diff --git a/.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.i18n.yaml b/.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.i18n.yaml
new file mode 100644
index 0000000000..20b1a4cfd5
--- /dev/null
+++ b/.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.i18n.yaml
@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write .agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.md
+2026-08-10-message-feedback-sidecar.md: 780cbaa840fcac7bcfa799468bfd61f5b08715cb
+2026-08-10-message-feedback-sidecar.zh.md: 72ecc82717010f65d013418a45c3b38c6084aaf9
diff --git a/.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.md b/.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.md
new file mode 100644
index 0000000000..780cbaa840
--- /dev/null
+++ b/.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.md
@@ -0,0 +1,43 @@
+# Agent Note: Lifecycle-bound message feedback sidecar
+
+Status: implemented
+
+English | [中文](2026-08-10-message-feedback-sidecar.zh.md)
+
+## Problem
+
+The existing `/feedback` command records an immutable Session-level `feedback/record` event. That event can release a pending telemetry prefix under `FEEDBACK_ONLY`, so it is the wrong authority for an editable positive/negative rating and optional note attached to one assistant message. Message feedback needs independent update and delete semantics without entering the canonical Session log, changing a projection, reaching the model surface, or implicitly consenting to telemetry.
+
+A sidecar keyed only by `SessionId` can outlive the log lifecycle it describes when an id is recreated with a different header identity. A Session-wide revision also makes unrelated message edits conflict, while plain storage-domain read/put has no cross-process compare-and-swap. Session disposal is only live-store detach, not durable deletion, and the current Session persistence seam exposes no deletion operation that could own a truthful cascade.
+
+## Decision
+
+`@deepseek-ai/dsh-message-feedback` owns the `ctx.messageFeedback` service and stores message feedback as one storage-domain sidecar row per Session. The sidecar is neither Session-log content nor a Session projection. It emits no `feedback/record` event and performs no telemetry handoff; the command-feedback and message-feedback contracts remain independent.
+
+Every usable row is bound to the inspected Session header identity `{createdAt, cwd}`, not merely its `SessionId`. A lifecycle mismatch is treated as absence: `list` returns no items, and `put` may replace the stale row with one bound to the current identity. An id reused with a different header identity therefore cannot inherit stale feedback. A fork receives its own Session identity and no sidecar copy: even when the fork seed contains the same assistant messages, feedback remains attached to the Session in which the human recorded it.
+
+`put` accepts a target only when `SessionPersistence.inspect()` observes a non-empty, append-origin `assistant/message` with that `MessageId`. Replacement-origin messages, empty usage-only assistant records, and non-assistant targets are rejected. Inspection is the cold-safe authority: it neither publishes or resumes an Agent nor commits cold-log repair merely to validate feedback. A cold `listSnapshots()` preflight classifies definite absence; inspection failure for a catalogued Session remains an infrastructure failure. A request in the narrow live-detach-to-header-materialization interval can therefore return `session-not-found`, and the caller retries after retirement materialization.
+
+Before `put` commits a sidecar row, it puts the target log behind a durability barrier. A matching live Session passes through the canonical `ctx.sessions.flush` checkpoint, then both live and cold paths are physically read from sequence zero through `SessionPersistence.readFrom`. The resulting observation's header identity and target are checked again. A missing flush participant, changed identity, vanished target, or physical-read failure prevents the sidecar write, so a committed feedback item never precedes the durable assistant message it references.
+
+Each message item carries its own opaque version plus Host-assigned `createdAt` and `updatedAt` timestamps. `put` compares the caller's `ifVersion` only with the addressed item, so editing one message does not invalidate another. The comparison is strict even when the desired value already matches, preventing a stale request from crossing an ABA value cycle; a conflict returns the authoritative current item so callers can reconcile without a second read. A matching-version no-op preserves the version and timestamps, while a material update preserves `createdAt`, replaces the version, and keeps `updatedAt` from moving backward. An already-absent delete is likewise successful. Versions are tokens for equality, not counters callers may order or synthesize.
+
+A per-Session mutation queue encloses lifecycle inspection, sidecar read, conflict evaluation, and whole-row write. This makes one service instance's mutations serial and preserves the per-message compare-and-swap contract inside one Host process. Plugin disposal closes admission, drains accepted queue work, and then closes the storage domain. The underlying storage-domain API provides no cross-process conditional write, so the implementation claims no cross-process linearizability or lost-update protection.
+
+`maxNoteBytes` is a required deployment choice and bounds the UTF-8 byte length of an optional note; the Web Host bundle sets it explicitly to `8192`. The package publishes the Host `messageFeedback.list`, `messageFeedback.put`, and `messageFeedback.delete` contract directly through `GatewayService` and `@Remote`. Client Remote aggregate mounting and UI remain separately owned and deferred; their later adapter stays a thin consumer of this Host contract.
+
+The service performs no fake deletion cascade. `session/disposed` and `host/session-removed` describe detach from live ownership, not durable Session deletion, and Session persistence currently has no delete surface. Sidecar rows can therefore remain after out-of-band log removal; a different `{createdAt, cwd}` prevents such an orphan from becoming feedback for a later Session that reuses the id.
+
+## Alternatives considered
+
+**Append edits to the Session log and derive a projection.** Rejected because editable UI metadata would become canonical conversation-adjacent history, forks would replay and inherit it, deletion would require tombstones, and reusing `feedback/record` would silently couple a message rating to telemetry consent.
+
+**Key feedback globally by `MessageId`, copy it on fork, or use one Session revision.** Rejected because message ids are meaningful only within a Session lifecycle, forked conversations need independent human judgments, and unrelated message mutations must not create false conflicts.
+
+**Extend `KvTable` with cross-process compare-and-swap in this change.** Rejected because the shipped storage-domain backends expose no common conditional-write primitive. A process-local queue matches the supported one-Host topology; a real multi-process guarantee requires a backend-level atomic contract and is separate work.
+
+**Delete feedback on Session disposal.** Rejected because disposal includes ordinary detach and rollback paths. Treating it as durable deletion would lose feedback while the Session log still exists; cleanup waits for a real Session deletion authority.
+
+## Consequences
+
+Message feedback is locally durable and independently editable without changing model-visible history or telemetry behavior. Concurrent callers in one Host receive per-message conflict detection and retry-safe outcomes, while deployments with multiple writers to the same storage root remain unsupported. A differing header identity treats a stale row as absent but does not reclaim it; a cloned log that retains the same `{createdAt, cwd}` is indistinguishable by this contract. The Host Remote contract is available now; client assembly and UI can remain thin consumers rather than taking ownership of persistence or concurrency semantics.
diff --git a/.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.zh.md b/.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.zh.md
new file mode 100644
index 0000000000..72ecc82717
--- /dev/null
+++ b/.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.zh.md
@@ -0,0 +1,43 @@
+# Agent Note: 绑定生命周期的消息反馈伴随记录
+
+Status: implemented
+
+[English](2026-08-10-message-feedback-sidecar.md) | 中文
+
+## 问题
+
+现有 `/feedback` 命令记录不可变的 Session 级 `feedback/record` 事件。在 `FEEDBACK_ONLY` 下，该事件可以释放待处理的遥测前缀，因此它不适合作为挂在单条 assistant 消息上的可编辑好评／差评与可选备注的权威来源。消息反馈需要独立的更新与删除语义，且不得进入权威 Session 日志、改变投影、到达模型接口，或隐式表示遥测同意。
+
+只按 `SessionId` 建索引的伴随记录可能在该 id 以不同 header 身份重建后，继续存活于其所描述的日志生命周期之外。Session 级 revision 还会让无关消息的编辑彼此冲突，而普通 storage-domain 读／写不提供跨进程 compare-and-swap。Session disposal 只是从 live store 脱离，并非持久删除；当前 Session 持久化 seam 也没有可拥有真实级联的删除操作。
+
+## 决策
+
+`@deepseek-ai/dsh-message-feedback` 拥有 `ctx.messageFeedback` 服务，并把消息反馈存为每个 Session 一条 storage-domain 伴随记录（sidecar）。该伴随记录既不是 Session 日志内容，也不是 Session 投影。它不发出 `feedback/record` 事件，也不执行遥测交接；command-feedback 与 message-feedback 契约保持独立。
+
+每条可用记录都绑定到经检查的 Session header 身份 `{createdAt, cwd}`，而不只是其 `SessionId`。生命周期不匹配按不存在处理：`list` 返回空条目，`put` 可以用绑定当前身份的新记录替换陈旧行。因此，以不同 header 身份复用的 id 不会继承陈旧反馈。fork 拥有自己的 Session 身份，且不复制伴随记录：即使 fork 种子包含相同的 assistant 消息，反馈仍只属于人类记录它的那个 Session。
+
+`put` 只接受由 `SessionPersistence.inspect()` 观测到的非空、append-origin `assistant/message`，且其 `MessageId` 必须与目标相同。replacement-origin 消息、仅承载 usage 的空 assistant 记录以及非 assistant 目标都会被拒绝。检查使用 cold-safe 权威路径：它不会仅为验证反馈而发布或恢复 Agent，也不会提交 cold 日志修复。cold 路径由 `listSnapshots()` 预检明确不存在；已进入目录的 Session 若检查失败，仍按基础设施故障处理。因此，请求若恰落在 live detach 到 header materialization 的极短窗口，可能返回 `session-not-found`，调用方在 retirement materialization 后重试。
+
+`put` 提交伴随记录前，会先让目标日志通过 durability barrier。身份匹配的 live Session 经过权威 `ctx.sessions.flush` checkpoint，随后 live 与 cold 路径都会通过 `SessionPersistence.readFrom` 从序列零做物理复读。之后再次校验所得观测的 header 身份与目标。缺少 flush 参与方、身份变化、目标消失或物理读取失败都会阻止伴随记录写入，因此已提交反馈绝不会先于它引用的持久 assistant 消息。
+
+每个消息条目都携带自己的 opaque version，以及 Host 分配的 `createdAt` 和 `updatedAt` 时间戳。`put` 只把调用方的 `ifVersion` 与目标条目比较，因此编辑一条消息不会使另一条消息失效。即使目标值已经相同，比较仍然严格执行，从而防止陈旧请求穿过 ABA 值循环；冲突会返回权威当前条目，调用方无需二次读取即可协调。携带匹配 version 的无变化请求会保留 version 与时间戳；实质更新保留 `createdAt`、替换 version，并保证 `updatedAt` 不倒退。删除已经不存在的条目也同样成功。version 是只能做相等比较的 token，不是调用方可以排序或自行合成的计数器。
+
+按 Session 划分的变更队列覆盖生命周期检查、伴随记录读取、冲突判断与整行写入。这使同一个服务实例的变更串行化，并在单个 Host 进程内保持逐消息 compare-and-swap 契约。Plugin disposal 会关闭接纳、排空已进入队列的工作，然后关闭 storage domain。底层 storage-domain API 不提供跨进程条件写，因此实现不承诺跨进程线性一致性或防止丢失更新。
+
+`maxNoteBytes` 是必填的部署选择，用于限制可选备注的 UTF-8 字节长度；Web Host bundle 将其显式设为 `8192`。该包通过 `GatewayService` 与 `@Remote` 直接发布 Host `messageFeedback.list`、`messageFeedback.put` 与 `messageFeedback.delete` 契约。客户端 Remote 聚合挂载与 UI 由各自边界负责并保持延后；后续适配层只是该 Host 契约的薄消费者。
+
+服务不伪造删除级联。`session/disposed` 与 `host/session-removed` 表示脱离 live ownership，而非持久删除，Session persistence 当前也没有删除接口。因此在带外移除日志后，伴随记录可能继续存在；不同的 `{createdAt, cwd}` 可阻止此类孤儿记录变成后来复用该 id 的 Session 反馈。
+
+## 考虑过的替代方案
+
+**把编辑追加到 Session 日志并派生投影。** 不予采纳，因为可编辑 UI 元数据会变成权威且邻近对话的历史，fork 会回放并继承它，删除需要 tombstone，而复用 `feedback/record` 会把消息评分与遥测同意静默耦合。
+
+**按全局 `MessageId` 建索引、在 fork 时复制，或使用一个 Session revision。** 不予采纳，因为消息 id 仅在某个 Session 生命周期内有意义，fork 后的对话需要独立的人类判断，而且无关消息的变更不应制造虚假冲突。
+
+**在本次变更中为 `KvTable` 扩展跨进程 compare-and-swap。** 不予采纳，因为出厂 storage-domain 后端没有共同的条件写原语。进程内队列符合受支持的单 Host 拓扑；真实的多进程保证需要后端级原子契约，属于独立工作。
+
+**在 Session disposal 时删除反馈。** 不予采纳，因为 disposal 包含普通 detach 与 rollback 路径。把它当成持久删除会在 Session 日志仍存在时丢失反馈；清理必须等待真正的 Session 删除权威。
+
+## 后果
+
+消息反馈在本地持久化并可独立编辑，且不改变模型可见历史或遥测行为。同一 Host 中的并发调用方获得逐消息冲突检测与可安全重试的结果；多个写入者共享同一存储根目录的部署仍不受支持。不同的 header 身份会让陈旧记录被视为不存在，但不会将其回收；本契约无法区分保留相同 `{createdAt, cwd}` 的克隆日志。Host Remote 契约现在可用；客户端组装与 UI 可以保持为薄消费者，而不接管持久化或并发语义。
diff --git a/apps/web/tests/message-feedback-protocol.snapshot.ts b/apps/web/tests/message-feedback-protocol.snapshot.ts
new file mode 100644
index 0000000000..9fbc556f77
--- /dev/null
+++ b/apps/web/tests/message-feedback-protocol.snapshot.ts
@@ -0,0 +1,115 @@
+import { readFile } from 'node:fs/promises'
+import { join } from 'node:path'
+import { fileURLToPath } from 'node:url'
+import { afterAll, beforeAll, describe, expect, it } from 'vitest'
+import {
+  assertFixtureInventory,
+  compareOrRefreshGolden,
+  launchWebScaffold,
+  seedSession,
+  type WebScaffold,
+} from './scaffold.ts'
+
+const SNAPSHOT_DIR = fileURLToPath(new URL('./snapshots/message-feedback-protocol', import.meta.url))
+const SESSION_FIXTURE = join(SNAPSHOT_DIR, 'session.jsonl')
+const PROTOCOL_EXPECTED = join(SNAPSHOT_DIR, 'protocol.expected.json')
+const SESSION_ID = 'message-feedback-protocol'
+const MESSAGE_ID = '11111111-1111-4111-8111-111111111111'
+
+interface ProtocolExchange {
+  readonly endpoint: string
+  readonly request: unknown
+  readonly status: number
+  readonly response: unknown
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null
+}
+
+/** Extract the opaque item version while keeping every surrounding wire field snapshot-owned. */
+function createdVersion(response: unknown): string {
+  if (!isRecord(response) || !isRecord(response.result) || response.result.ok !== true
+    || !isRecord(response.result.value) || response.result.value.ok !== true
+    || !isRecord(response.result.value.value)
+    || typeof response.result.value.value.version !== 'string') {
+    throw new Error('messageFeedback.put did not return a successful versioned item')
+  }
+  return response.result.value.value.version
+}
+
+/** Replace only run-owned UUID/time values; all protocol names and business fields stay exact. */
+function normalizeProtocol(exchanges: readonly ProtocolExchange[], version: string): string {
+  return JSON.stringify(exchanges, (key, value: unknown) => {
+    if ((key === 'version' || key === 'ifVersion') && value === version) return '{{version}}'
+    if ((key === 'createdAt' || key === 'updatedAt') && typeof value === 'number') return '{{timestamp}}'
+    return value
+  }, 2)
+}
+
+describe('message feedback Host Remote protocol', () => {
+  let scaffold: WebScaffold
+
+  beforeAll(async () => {
+    scaffold = await launchWebScaffold()
+    await seedSession(scaffold, await readFile(SESSION_FIXTURE, 'utf8'), SESSION_ID)
+  })
+
+  afterAll(async () => {
+    await scaffold?.close()
+  })
+
+  it('snapshots strict list, put, conflict, and delete calls through the shipped Web Host', async () => {
+    const exchanges: ProtocolExchange[] = []
+    const invoke = async (rpcId: string, endpoint: string, request: unknown): Promise<unknown> => {
+      const payload = { args: { request } }
+      const response = await fetch(`${scaffold.baseUrl}/api/${endpoint}`, {
+        method: 'POST',
+        headers: { 'content-type': 'application/json' },
+        body: JSON.stringify({
+          type: 'client-request',
+          rpcId,
+          method: endpoint,
+          payload,
+        }),
+      })
+      const body: unknown = await response.json()
+      exchanges.push({ endpoint: `/api/${endpoint}`, request: payload, status: response.status, response: body })
+      return body
+    }
+
+    await invoke('feedback-invalid', 'messageFeedback/put', {
+      sessionId: SESSION_ID,
+      messageId: MESSAGE_ID,
+      rating: 'invalid-rating',
+      ifVersion: null,
+    })
+    await invoke('feedback-list-empty', 'messageFeedback/list', { sessionId: SESSION_ID })
+    const created = await invoke('feedback-put', 'messageFeedback/put', {
+      sessionId: SESSION_ID,
+      messageId: MESSAGE_ID,
+      rating: 'positive',
+      note: 'Useful answer',
+      ifVersion: null,
+    })
+    const version = createdVersion(created)
+    expect(version).toMatch(/^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/)
+    await invoke('feedback-list-created', 'messageFeedback/list', { sessionId: SESSION_ID })
+    await invoke('feedback-conflict', 'messageFeedback/put', {
+      sessionId: SESSION_ID,
+      messageId: MESSAGE_ID,
+      rating: 'negative',
+      ifVersion: null,
+    })
+    await invoke('feedback-delete', 'messageFeedback/delete', {
+      sessionId: SESSION_ID,
+      messageId: MESSAGE_ID,
+      ifVersion: version,
+    })
+    await invoke('feedback-list-deleted', 'messageFeedback/list', { sessionId: SESSION_ID })
+
+    expect(exchanges.every(exchange => exchange.status === 200)).toBe(true)
+    await compareOrRefreshGolden(PROTOCOL_EXPECTED, normalizeProtocol(exchanges, version), scaffold.mode)
+    await assertFixtureInventory(SNAPSHOT_DIR, ['protocol.expected.json', 'session.jsonl'])
+  })
+})
diff --git a/apps/web/tests/snapshots/message-feedback-protocol/protocol.expected.json b/apps/web/tests/snapshots/message-feedback-protocol/protocol.expected.json
new file mode 100644
index 0000000000..302e4876df
--- /dev/null
+++ b/apps/web/tests/snapshots/message-feedback-protocol/protocol.expected.json
@@ -0,0 +1,203 @@
+[
+  {
+    "endpoint": "/api/messageFeedback/put",
+    "request": {
+      "args": {
+        "request": {
+          "sessionId": "message-feedback-protocol",
+          "messageId": "11111111-1111-4111-8111-111111111111",
+          "rating": "invalid-rating",
+          "ifVersion": null
+        }
+      }
+    },
+    "status": 200,
+    "response": {
+      "type": "server-response",
+      "rpcId": "feedback-invalid",
+      "result": {
+        "ok": false,
+        "error": {
+          "code": "internal",
+          "message": "typert gateway: messageFeedback/put: wire field \"request\" failed boundary validation",
+          "details": {}
+        }
+      }
+    }
+  },
+  {
+    "endpoint": "/api/messageFeedback/list",
+    "request": {
+      "args": {
+        "request": {
+          "sessionId": "message-feedback-protocol"
+        }
+      }
+    },
+    "status": 200,
+    "response": {
+      "type": "server-response",
+      "rpcId": "feedback-list-empty",
+      "result": {
+        "ok": true,
+        "value": {
+          "ok": true,
+          "value": {
+            "items": []
+          }
+        }
+      }
+    }
+  },
+  {
+    "endpoint": "/api/messageFeedback/put",
+    "request": {
+      "args": {
+        "request": {
+          "sessionId": "message-feedback-protocol",
+          "messageId": "11111111-1111-4111-8111-111111111111",
+          "rating": "positive",
+          "note": "Useful answer",
+          "ifVersion": null
+        }
+      }
+    },
+    "status": 200,
+    "response": {
+      "type": "server-response",
+      "rpcId": "feedback-put",
+      "result": {
+        "ok": true,
+        "value": {
+          "ok": true,
+          "value": {
+            "messageId": "11111111-1111-4111-8111-111111111111",
+            "rating": "positive",
+            "note": "Useful answer",
+            "version": "{{version}}",
+            "createdAt": "{{timestamp}}",
+            "updatedAt": "{{timestamp}}"
+          }
+        }
+      }
+    }
+  },
+  {
+    "endpoint": "/api/messageFeedback/list",
+    "request": {
+      "args": {
+        "request": {
+          "sessionId": "message-feedback-protocol"
+        }
+      }
+    },
+    "status": 200,
+    "response": {
+      "type": "server-response",
+      "rpcId": "feedback-list-created",
+      "result": {
+        "ok": true,
+        "value": {
+          "ok": true,
+          "value": {
+            "items": [
+              {
+                "messageId": "11111111-1111-4111-8111-111111111111",
+                "rating": "positive",
+                "note": "Useful answer",
+                "version": "{{version}}",
+                "createdAt": "{{timestamp}}",
+                "updatedAt": "{{timestamp}}"
+              }
+            ]
+          }
+        }
+      }
+    }
+  },
+  {
+    "endpoint": "/api/messageFeedback/put",
+    "request": {
+      "args": {
+        "request": {
+          "sessionId": "message-feedback-protocol",
+          "messageId": "11111111-1111-4111-8111-111111111111",
+          "rating": "negative",
+          "ifVersion": null
+        }
+      }
+    },
+    "status": 200,
+    "response": {
+      "type": "server-response",
+      "rpcId": "feedback-conflict",
+      "result": {
+        "ok": true,
+        "value": {
+          "ok": false,
+          "error": {
+            "code": "version-conflict",
+            "current": {
+              "messageId": "11111111-1111-4111-8111-111111111111",
+              "rating": "positive",
+              "note": "Useful answer",
+              "version": "{{version}}",
+              "createdAt": "{{timestamp}}",
+              "updatedAt": "{{timestamp}}"
+            }
+          }
+        }
+      }
+    }
+  },
+  {
+    "endpoint": "/api/messageFeedback/delete",
+    "request": {
+      "args": {
+        "request": {
+          "sessionId": "message-feedback-protocol",
+          "messageId": "11111111-1111-4111-8111-111111111111",
+          "ifVersion": "{{version}}"
+        }
+      }
+    },
+    "status": 200,
+    "response": {
+      "type": "server-response",
+      "rpcId": "feedback-delete",
+      "result": {
+        "ok": true,
+        "value": {
+          "ok": true,
+          "value": {
+            "absent": true
+          }
+        }
+      }
+    }
+  },
+  {
+    "endpoint": "/api/messageFeedback/list",
+    "request": {
+      "args": {
+        "request": {
+          "sessionId": "message-feedback-protocol"
+        }
+      }
+    },
+    "status": 200,
+    "response": {
+      "type": "server-response",
+      "rpcId": "feedback-list-deleted",
+      "result": {
+        "ok": true,
+        "value": {
+          "ok": true,
+          "value": {
+            "items": []
+          }
+        }
+      }
+    }
+  }
+]
diff --git a/apps/web/tests/snapshots/message-feedback-protocol/session.jsonl b/apps/web/tests/snapshots/message-feedback-protocol/session.jsonl
new file mode 100644
index 0000000000..d970fb8cb4
--- /dev/null
+++ b/apps/web/tests/snapshots/message-feedback-protocol/session.jsonl
@@ -0,0 +1,7 @@
+{"type":"session","version":0,"id":"{{sessionId}}","createdAt":1786406400000,"cwd":"{{cwd}}"}
+{"type":"turn/start","seq":0,"time":1786406400001,"data":{"turn":1}}
+{"type":"user/message","seq":1,"time":1786406400002,"data":{"role":"user","content":[{"type":"text","text":"Give one useful answer."}],"source":{"kind":"user"},"id":"22222222-2222-4222-8222-222222222222"},"surfaceOp":"append"}
+{"type":"step/start","seq":2,"time":1786406400003,"data":{"turn":1,"step":1}}
+{"type":"assistant/message","seq":3,"time":1786406400004,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"text","text":"A useful answer."}],"source":{"kind":"model","provider":"fixture","model":"fixture"},"id":"11111111-1111-4111-8111-111111111111"},"usage":{"inputTokens":4,"outputTokens":4}},"surfaceOp":"append"}
+{"type":"step/end","seq":4,"time":1786406400005,"data":{"turn":1,"step":1}}
+{"type":"turn/end","seq":5,"time":1786406400006,"data":{"turn":1,"reason":{"kind":"completed"}}}
diff --git a/apps/web/tsconfig.json b/apps/web/tsconfig.json
index b80a2f6e2b..f96a1f8dd1 100644
--- a/apps/web/tsconfig.json
+++ b/apps/web/tsconfig.json
@@ -25,6 +25,7 @@
     "tests/scaffold.ts",
     "tests/scaffold-hermetic.e2e.ts",
     "tests/minimal-preset.snapshot.ts",
+    "tests/message-feedback-protocol.snapshot.ts",
     "tests/live-interactions.e2e.ts",
     "tests/question-composer.e2e.ts",
     "tests/approval-composer.e2e.ts",
diff --git a/docs/architecture.i18n.yaml b/docs/architecture.i18n.yaml
index 344bac8145..ea8b934c79 100644
--- a/docs/architecture.i18n.yaml
+++ b/docs/architecture.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/architecture.md
-architecture.md: 8d1c5a1be391e2455aefc69db89d96027aaf3efa
-architecture.zh.md: 53bf9f54a5503ae40aa62a348822f9d92162dda2
+architecture.md: aeda7f9674e75a1e97549f25c13d571b3b37ee8c
+architecture.zh.md: a25f20ba9babefeaab4636027e97d6f2d4ae8caf
diff --git a/docs/architecture.md b/docs/architecture.md
index 8d1c5a1be3..aeda7f9674 100644
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -42,6 +42,7 @@ Harnesses are [Cordis](cordis-primer.md) contexts; packages contribute services,
 | `ctx.tasks` | [`tasks/`](../packages/tasks/README.md) | background task registry, generic `task_*` controls |
 | `ctx.workflows` | [`workflow/`](../packages/workflow/README.md) | script-driven multi-agent orchestration |
 | `ctx.goals` | [`goal/`](../packages/goal/README.md) | persisted same-session goals |
+| `ctx.messageFeedback` | [`feedback/`](../packages/feedback/README.md) | lifecycle-bound editable feedback for individual assistant messages and its Host Remote contract |
 | `ctx.sessionPersistence` | [`session/`](../packages/session/README.md) | durable session-log storage |
 | `ctx.sessionQuery` | [`session-query/`](../packages/session-query/README.md) | live-preferred exact/filter/trace queries over SQLite FTS, workspace-authorized model tools |
 | `ctx.sessionTitle` | [`session/session-title`](../packages/session/README.md) | log-backed fallbacks, one optional asynchronous provider |
diff --git a/docs/architecture.zh.md b/docs/architecture.zh.md
index 53bf9f54a5..a25f20ba9b 100644
--- a/docs/architecture.zh.md
+++ b/docs/architecture.zh.md
@@ -42,6 +42,7 @@
 | `ctx.tasks` | [`tasks/`](../packages/tasks/README.md) | 后台任务注册表和通用 `task_*` 控制 |
 | `ctx.workflows` | [`workflow/`](../packages/workflow/README.md) | 脚本驱动的多 agent 编排 |
 | `ctx.goals` | [`goal/`](../packages/goal/README.md) | 持久化的同会话目标 |
+| `ctx.messageFeedback` | [`feedback/`](../packages/feedback/README.md) | 绑定生命周期的单条 assistant 消息可编辑反馈及其 Host Remote 契约 |
 | `ctx.sessionPersistence` | [`session/`](../packages/session/README.md) | 会话日志的持久化存储 |
 | `ctx.sessionQuery` | [`session-query/`](../packages/session-query/README.md) | 基于 SQLite 全文搜索的实时优先精确检索／过滤／追踪、经工作区授权的模型工具 |
 | `ctx.sessionTitle` | [`session/session-title`](../packages/session/README.md) | 基于日志的回退标题和单个可选异步提供方 |
diff --git a/docs/capability-seams.i18n.yaml b/docs/capability-seams.i18n.yaml
index d6c4832447..c0091e400e 100644
--- a/docs/capability-seams.i18n.yaml
+++ b/docs/capability-seams.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/capability-seams.md
-capability-seams.md: c102167aa76b9ba613b1b434cb0aa58765d26106
-capability-seams.zh.md: 7c4eab8d5a2d890bdf4513bb9acdc81f55414642
+capability-seams.md: 64d20b1bfb609aec3acb3673e4589516bb315bfa
+capability-seams.zh.md: 10b5116d12991319df55c551d51840bb566ac898
diff --git a/docs/capability-seams.md b/docs/capability-seams.md
index c102167aa7..64d20b1bfb 100644
--- a/docs/capability-seams.md
+++ b/docs/capability-seams.md
@@ -30,6 +30,7 @@ flowchart LR
   pkg_session_query_sqlite["session-query-sqlite"]
   pkg_subagent_inprocess["subagent-inprocess"]
   pkg_invariants["invariants"]
+  pkg_message_feedback["message-feedback"]
   svc_invariants["ctx.invariants<br/>Package-owned invariant registry"]
   pkg_scope["scope"]
   pkg_typert_registry["typert-registry"]
@@ -60,6 +61,7 @@ flowchart LR
   pkg_storage_domain["storage-domain"]
   svc_storageDomain["ctx.storageDomain<br/>Domain data facility"]
   pkg_workspace["workspace"]
+  svc_messageFeedback["ctx.messageFeedback<br/>Lifecycle-bound message feedback"]
   svc_workspace["ctx.workspace<br/>Workspace entity registry"]
   svc_sessionQuery["ctx.sessionQuery<br/>Session reads, traces, filters, and search"]
   pkg_session_reference["session-reference"]
@@ -218,6 +220,7 @@ flowchart LR
   pkg_llm_deepseek --> svc_llm
   pkg_llm_pi_ai --> svc_llm
   pkg_llm_replay --> svc_llm
+  pkg_message_feedback --> svc_messageFeedback
   pkg_modules --> svc_clientModuleHost
   pkg_permission --> svc_permission
   pkg_plan_mode --> svc_planMode
@@ -322,6 +325,7 @@ flowchart LR
   svc_sessionPersistence --> pkg_agent_loop
   svc_sessionPersistence --> pkg_hooks_claude
   svc_sessionPersistence --> pkg_hooks_codex
+  svc_sessionPersistence --> pkg_message_feedback
   svc_sessionPersistence --> pkg_session_query
   svc_sessionPersistence --> pkg_session_query_sqlite
   svc_sessionPersistence --> pkg_tool_bash
@@ -334,6 +338,7 @@ flowchart LR
   svc_sessions --> pkg_agent
   svc_sessions --> pkg_agent_loop
   svc_sessions --> pkg_invariants
+  svc_sessions --> pkg_message_feedback
   svc_sessions --> pkg_session_persistence
   svc_sessions --> pkg_session_query
   svc_sessions --> pkg_session_query_sqlite
@@ -344,6 +349,7 @@ flowchart LR
   svc_skills --> pkg_tool_skill
   svc_spillStore --> pkg_spill_policy
   svc_storage --> pkg_storage_domain
+  svc_storageDomain --> pkg_message_feedback
   svc_storageDomain --> pkg_workspace
   svc_subagents --> pkg_tool_ralph
   svc_subagents --> pkg_tool_subagent
@@ -392,16 +398,17 @@ flowchart LR
 | `ctx.llm` | `seam` | [`llm`](../packages/llm/llm) | [`llm-deepseek`](../packages/llm/llm-deepseek), [`llm-pi-ai`](../packages/llm/llm-pi-ai), [`llm-replay`](../packages/support/llm-replay) | [`agent-loop`](../packages/core/agent-loop), [`compact-basic`](../packages/compact/compact-basic) | - | Adapters register provider implementations; the loop and compaction call the provider-neutral stream service. |
 | `ctx.tokenMeter` | `core` | [`token-meter`](../packages/llm/token-meter) | - | [`compact-basic`](../packages/compact/compact-basic) | - | Owns isolated per-session replay folds; pressure consumers share immutable revisioned measurements. |
 | `ctx.toolResultPrune` | `core` | [`compact-tool-result-prune`](../packages/compact/compact-tool-result-prune) | - | [`compact-basic`](../packages/compact/compact-basic) | - | Rewrites oversized current tool results through replayable single-node surface replacements before summary compaction. |
-| `ctx.sessions` | `core` | [`session`](../packages/core/session) | - | [`agent-loop`](../packages/core/agent-loop), [`agent`](../packages/core/agent), [`session-persistence`](../packages/session/session-persistence), [`session-query`](../packages/session-query/session-query), [`session-query-sqlite`](../packages/session-query/session-query-sqlite), [`subagent-inprocess`](../packages/subagent/subagent-inprocess), [`invariants`](../packages/support/invariants) | - | Owns append-only Session instances and emits the durable session event feed. |
+| `ctx.sessions` | `core` | [`session`](../packages/core/session) | - | [`agent-loop`](../packages/core/agent-loop), [`agent`](../packages/core/agent), [`session-persistence`](../packages/session/session-persistence), [`session-query`](../packages/session-query/session-query), [`session-query-sqlite`](../packages/session-query/session-query-sqlite), [`subagent-inprocess`](../packages/subagent/subagent-inprocess), [`invariants`](../packages/support/invariants), [`message-feedback`](../packages/feedback/message-feedback) | - | Owns append-only Session instances and emits the durable session event feed. |
 | `ctx.invariants` | `core` | [`invariants`](../packages/support/invariants) | - | [`session`](../packages/core/session), [`agent`](../packages/core/agent), [`scope`](../packages/core/scope), [`agent-loop`](../packages/core/agent-loop) | - | Companion subpaths register owner-local checks; the service owns selection, uniqueness, child fibers, and package-attributed failures. |
 | `ctx.typert` | `core` | [`typert-registry`](../packages/typert/registry) | - | [`typert-loader`](../packages/typert/loader), [`api-gateway`](../packages/api/gateway) | - | Plugins register live zod contributions directly or through dsh-typert-loader; the API gateway consumes invocation descriptors and providers, while other runtime consumers query schemas and reflection metadata at their own edges. |
 | `ctx.typertGateway` | `core` | [`api-gateway`](../packages/api/gateway) | - | - | - | Associates generated Remote descriptors with live Cordis services, resolves registered identities, and exposes unary calls through the shared Connection RPC carrier. |
-| `ctx.sessionPersistence` | `seam` | [`session-persistence`](../packages/session/session-persistence) | [`session-persistence-jsonl`](../packages/session/session-persistence-jsonl), [`session-persistence-sqlite`](../packages/session/session-persistence-sqlite) | [`agent-loop`](../packages/core/agent-loop), [`tool-bash`](../packages/bash/tool-bash), [`hooks-claude`](../packages/hooks/hooks-claude), [`hooks-codex`](../packages/hooks/hooks-codex), [`session-query`](../packages/session-query/session-query), [`session-query-sqlite`](../packages/session-query/session-query-sqlite) | - | Backends persist the same SessionEvent vocabulary; apps choose a backend at composition time. |
+| `ctx.sessionPersistence` | `seam` | [`session-persistence`](../packages/session/session-persistence) | [`session-persistence-jsonl`](../packages/session/session-persistence-jsonl), [`session-persistence-sqlite`](../packages/session/session-persistence-sqlite) | [`agent-loop`](../packages/core/agent-loop), [`tool-bash`](../packages/bash/tool-bash), [`hooks-claude`](../packages/hooks/hooks-claude), [`hooks-codex`](../packages/hooks/hooks-codex), [`session-query`](../packages/session-query/session-query), [`session-query-sqlite`](../packages/session-query/session-query-sqlite), [`message-feedback`](../packages/feedback/message-feedback) | - | Backends persist the same SessionEvent vocabulary; apps choose a backend at composition time. |
 | `ctx.settings` | `seam` | [`settings`](../packages/settings/settings) | [`settings-local`](../packages/settings/settings-local) | [`llm-deepseek`](../packages/llm/llm-deepseek), [`llm-pi-ai`](../packages/llm/llm-pi-ai), `apiproxy` | - | Plugins register namespace schemas and resolve layered values; providers store the raw document. The LLM adapters register their entry config as the composition base under the user section; the web gateway serves redacted layered descriptors and writes the user layer. |
 | `ctx.credentials` | `seam` | [`credentials`](../packages/credentials/credentials) | [`credentials-local`](../packages/credentials/credentials-local) | [`llm-deepseek`](../packages/llm/llm-deepseek), [`llm-pi-ai`](../packages/llm/llm-pi-ai), `apiproxy` | - | Configuration carries references to secrets; providers own the values. Consumers resolve per operation, so a rotated credential reaches the very next request; the web gateway exposes value-free views and write-only storage. |
 | `ctx.telemetry` | `seam` | [`session-telemetry`](../packages/session/session-telemetry) | [`session-telemetry-otel`](../packages/session/session-telemetry-otel) | - | - | The seam captures, redacts, and hands session records to one backend; nothing else consumes the service — its output leaves the process. |
 | `ctx.storage` | `seam` | [`storage`](../packages/storage/storage) | [`storage-json`](../packages/storage/storage-json), [`storage-sqlite`](../packages/storage/storage-sqlite) | [`storage-domain`](../packages/storage/storage-domain) | - | Backends register side by side under names; data forms (domain first) mount on the hub and translate typed operations into opaque KV-unit primitives. |
-| `ctx.storageDomain` | `core` | [`storage-domain`](../packages/storage/storage-domain) | - | [`workspace`](../packages/workspace/workspace) | - | Waits for every configured backend, then publishes the domain form as one lifecycle-bound service for typed durable state. |
+| `ctx.storageDomain` | `core` | [`storage-domain`](../packages/storage/storage-domain) | - | [`workspace`](../packages/workspace/workspace), [`message-feedback`](../packages/feedback/message-feedback) | - | Waits for every configured backend, then publishes the domain form as one lifecycle-bound service for typed durable state. |
+| `ctx.messageFeedback` | `core` | [`message-feedback`](../packages/feedback/message-feedback) | - | - | - | Owns local per-assistant-message feedback, lifecycle and target validation, per-item compare-and-set, and the Host unary Remote contract without entering Session history or telemetry. |
 | `ctx.workspace` | `core` | [`workspace`](../packages/workspace/workspace) | - | `apiproxy` | - | Owns WorkspaceId-branded records over the domain facility; stable sessionIds accounts drive Host RPC and GUI projections. |
 | `ctx.sessionQuery` | `seam` | [`session-query`](../packages/session-query/session-query) | [`session-query-sqlite`](../packages/session-query/session-query-sqlite) | [`session-reference`](../packages/context/session-reference), [`tool-session-query`](../packages/session-query/tool-session-query) | - | The interface supplies exact reads, filters, and traces; its concrete backend adds full-text reconciliation, ranking, snippets, and cursor generations, while the model consumer owns workspace authority and cursor-free rendering. |
 | `ctx.sessionReferences` | `core` | [`session-reference`](../packages/context/session-reference) | - | - | - | Projects bounded current-surface conversation snapshots into durable untrusted message context; host adapters own mention syntax. |
diff --git a/docs/capability-seams.zh.md b/docs/capability-seams.zh.md
index 7c4eab8d5a..10b5116d12 100644
--- a/docs/capability-seams.zh.md
+++ b/docs/capability-seams.zh.md
@@ -32,6 +32,7 @@ flowchart LR
   pkg_session_query_sqlite["session-query-sqlite"]
   pkg_subagent_inprocess["subagent-inprocess"]
   pkg_invariants["invariants"]
+  pkg_message_feedback["message-feedback"]
   svc_invariants["ctx.invariants<br/>Package-owned invariant registry"]
   pkg_scope["scope"]
   pkg_typert_registry["typert-registry"]
@@ -62,6 +63,7 @@ flowchart LR
   pkg_storage_domain["storage-domain"]
   svc_storageDomain["ctx.storageDomain<br/>Domain data facility"]
   pkg_workspace["workspace"]
+  svc_messageFeedback["ctx.messageFeedback<br/>Lifecycle-bound message feedback"]
   svc_workspace["ctx.workspace<br/>Workspace entity registry"]
   svc_sessionQuery["ctx.sessionQuery<br/>Session reads, traces, filters, and search"]
   pkg_session_reference["session-reference"]
@@ -220,6 +222,7 @@ flowchart LR
   pkg_llm_deepseek --> svc_llm
   pkg_llm_pi_ai --> svc_llm
   pkg_llm_replay --> svc_llm
+  pkg_message_feedback --> svc_messageFeedback
   pkg_modules --> svc_clientModuleHost
   pkg_permission --> svc_permission
   pkg_plan_mode --> svc_planMode
@@ -324,6 +327,7 @@ flowchart LR
   svc_sessionPersistence --> pkg_agent_loop
   svc_sessionPersistence --> pkg_hooks_claude
   svc_sessionPersistence --> pkg_hooks_codex
+  svc_sessionPersistence --> pkg_message_feedback
   svc_sessionPersistence --> pkg_session_query
   svc_sessionPersistence --> pkg_session_query_sqlite
   svc_sessionPersistence --> pkg_tool_bash
@@ -336,6 +340,7 @@ flowchart LR
   svc_sessions --> pkg_agent
   svc_sessions --> pkg_agent_loop
   svc_sessions --> pkg_invariants
+  svc_sessions --> pkg_message_feedback
   svc_sessions --> pkg_session_persistence
   svc_sessions --> pkg_session_query
   svc_sessions --> pkg_session_query_sqlite
@@ -346,6 +351,7 @@ flowchart LR
   svc_skills --> pkg_tool_skill
   svc_spillStore --> pkg_spill_policy
   svc_storage --> pkg_storage_domain
+  svc_storageDomain --> pkg_message_feedback
   svc_storageDomain --> pkg_workspace
   svc_subagents --> pkg_tool_ralph
   svc_subagents --> pkg_tool_subagent
@@ -394,16 +400,17 @@ flowchart LR
 | `ctx.llm` | `seam` | [`llm`](../packages/llm/llm) | [`llm-deepseek`](../packages/llm/llm-deepseek)、[`llm-pi-ai`](../packages/llm/llm-pi-ai)、[`llm-replay`](../packages/support/llm-replay) | [`agent-loop`](../packages/core/agent-loop)、[`compact-basic`](../packages/compact/compact-basic) | - | 适配器注册提供方实现；agent loop（智能体循环）与压缩功能调用提供方无关的流服务。 |
 | `ctx.tokenMeter` | `core` | [`token-meter`](../packages/llm/token-meter) | - | [`compact-basic`](../packages/compact/compact-basic) | - | 拥有按会话隔离的回放折叠区；压力消费方共享不可变且带修订版本的测量结果。 |
 | `ctx.toolResultPrune` | `core` | [`compact-tool-result-prune`](../packages/compact/compact-tool-result-prune) | - | [`compact-basic`](../packages/compact/compact-basic) | - | 在摘要压缩前，通过可回放的单节点表层替换来改写过大的当前工具结果。 |
-| `ctx.sessions` | `core` | [`session`](../packages/core/session) | - | [`agent-loop`](../packages/core/agent-loop)、[`agent`](../packages/core/agent)、[`session-persistence`](../packages/session/session-persistence)、[`session-query`](../packages/session-query/session-query)、[`session-query-sqlite`](../packages/session-query/session-query-sqlite)、[`subagent-inprocess`](../packages/subagent/subagent-inprocess)、[`invariants`](../packages/support/invariants) | - | 拥有仅追加的 Session 实例，并发出持久的会话事件流。 |
+| `ctx.sessions` | `core` | [`session`](../packages/core/session) | - | [`agent-loop`](../packages/core/agent-loop)、[`agent`](../packages/core/agent)、[`session-persistence`](../packages/session/session-persistence)、[`session-query`](../packages/session-query/session-query)、[`session-query-sqlite`](../packages/session-query/session-query-sqlite)、[`subagent-inprocess`](../packages/subagent/subagent-inprocess)、[`invariants`](../packages/support/invariants)、[`message-feedback`](../packages/feedback/message-feedback) | - | 拥有仅追加的 Session 实例，并发出持久的会话事件流。 |
 | `ctx.invariants` | `core` | [`invariants`](../packages/support/invariants) | - | [`session`](../packages/core/session)、[`agent`](../packages/core/agent)、[`scope`](../packages/core/scope)、[`agent-loop`](../packages/core/agent-loop) | - | 配套子路径注册所属包本地的检查；该服务负责选择、唯一性、子 fiber，以及标明所属包的失败。 |
 | `ctx.typert` | `core` | [`typert-registry`](../packages/typert/registry) | - | [`typert-loader`](../packages/typert/loader)、[`api-gateway`](../packages/api/gateway) | - | 插件直接或通过 dsh-typert-loader 注册实时 zod 贡献；API 网关消费调用描述符和提供方，其他运行时消费方则在各自边界查询 schema 与反射元数据。 |
 | `ctx.typertGateway` | `core` | [`api-gateway`](../packages/api/gateway) | - | - | - | 将生成的 Remote 描述符与实时 Cordis 服务关联，解析已注册的身份，并通过共享的 Connection RPC 载体提供一元调用。 |
-| `ctx.sessionPersistence` | `seam` | [`session-persistence`](../packages/session/session-persistence) | [`session-persistence-jsonl`](../packages/session/session-persistence-jsonl)、[`session-persistence-sqlite`](../packages/session/session-persistence-sqlite) | [`agent-loop`](../packages/core/agent-loop)、[`tool-bash`](../packages/bash/tool-bash)、[`hooks-claude`](../packages/hooks/hooks-claude)、[`hooks-codex`](../packages/hooks/hooks-codex)、[`session-query`](../packages/session-query/session-query)、[`session-query-sqlite`](../packages/session-query/session-query-sqlite) | - | 各后端持久化同一套 SessionEvent 词汇；应用在组合时选择后端。 |
+| `ctx.sessionPersistence` | `seam` | [`session-persistence`](../packages/session/session-persistence) | [`session-persistence-jsonl`](../packages/session/session-persistence-jsonl)、[`session-persistence-sqlite`](../packages/session/session-persistence-sqlite) | [`agent-loop`](../packages/core/agent-loop)、[`tool-bash`](../packages/bash/tool-bash)、[`hooks-claude`](../packages/hooks/hooks-claude)、[`hooks-codex`](../packages/hooks/hooks-codex)、[`session-query`](../packages/session-query/session-query)、[`session-query-sqlite`](../packages/session-query/session-query-sqlite)、[`message-feedback`](../packages/feedback/message-feedback) | - | 各后端持久化同一套 SessionEvent 词汇；应用在组合时选择后端。 |
 | `ctx.settings` | `seam` | [`settings`](../packages/settings/settings) | [`settings-local`](../packages/settings/settings-local) | [`llm-deepseek`](../packages/llm/llm-deepseek)、[`llm-pi-ai`](../packages/llm/llm-pi-ai)、`apiproxy` | - | 插件注册命名空间 schema 并解析分层值；提供方存储原始文档。LLM（大语言模型）适配器在用户分区下将其入口配置注册为组合基础；Web 网关提供经过脱敏的分层描述符，并写入用户层。 |
 | `ctx.credentials` | `seam` | [`credentials`](../packages/credentials/credentials) | [`credentials-local`](../packages/credentials/credentials-local) | [`llm-deepseek`](../packages/llm/llm-deepseek)、[`llm-pi-ai`](../packages/llm/llm-pi-ai)、`apiproxy` | - | 配置携带对机密信息的引用；提供方拥有实际值。消费方按操作解析，因此轮换后的凭据会在紧接着的下一次请求中生效；Web 网关提供不含实际值的视图和只写存储。 |
 | `ctx.telemetry` | `seam` | [`session-telemetry`](../packages/session/session-telemetry) | [`session-telemetry-otel`](../packages/session/session-telemetry-otel) | - | - | 该 seam 捕获会话记录、进行脱敏并交给一个后端；没有其他组件消费该服务，其输出会离开当前进程。 |
 | `ctx.storage` | `seam` | [`storage`](../packages/storage/storage) | [`storage-json`](../packages/storage/storage-json)、[`storage-sqlite`](../packages/storage/storage-sqlite) | [`storage-domain`](../packages/storage/storage-domain) | - | 各后端以不同名称并列注册；数据形态（领域优先）挂载到枢纽上，并将类型化操作转换为不透明的 KV 单元原语。 |
-| `ctx.storageDomain` | `core` | [`storage-domain`](../packages/storage/storage-domain) | - | [`workspace`](../packages/workspace/workspace) | - | 等待所有已配置后端就绪，然后将领域形态发布为一个受生命周期约束的服务，用于类型化持久状态。 |
+| `ctx.storageDomain` | `core` | [`storage-domain`](../packages/storage/storage-domain) | - | [`workspace`](../packages/workspace/workspace)、[`message-feedback`](../packages/feedback/message-feedback) | - | 等待所有已配置后端就绪，然后将领域形态发布为一个受生命周期约束的服务，用于类型化持久状态。 |
+| `ctx.messageFeedback` | `core` | [`message-feedback`](../packages/feedback/message-feedback) | - | - | - | 拥有本地逐 assistant 消息反馈、生命周期与目标校验、逐条目 compare-and-set 及 Host 一元 Remote 契约，且不进入 Session 历史或遥测。 |
 | `ctx.workspace` | `core` | [`workspace`](../packages/workspace/workspace) | - | `apiproxy` | - | 通过领域设施拥有带 WorkspaceId 品牌类型的记录；稳定的 sessionIds 账户驱动 Host RPC 与 GUI 投影。 |
 | `ctx.sessionQuery` | `seam` | [`session-query`](../packages/session-query/session-query) | [`session-query-sqlite`](../packages/session-query/session-query-sqlite) | [`session-reference`](../packages/context/session-reference)、[`tool-session-query`](../packages/session-query/tool-session-query) | - | 该接口提供精确读取、过滤和追踪；具体后端还提供全文协调、排序、摘要片段和游标世代，而模型消费方负责工作区权限与不含游标的渲染。 |
 | `ctx.sessionReferences` | `core` | [`session-reference`](../packages/context/session-reference) | - | - | - | 将当前表层中有界的对话快照投影为持久但不可信的消息上下文；Host 适配器负责提及语法。 |
diff --git a/docs/config-catalog.i18n.yaml b/docs/config-catalog.i18n.yaml
index f12b6e3637..a20a76a7ef 100644
--- a/docs/config-catalog.i18n.yaml
+++ b/docs/config-catalog.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/config-catalog.md
-config-catalog.md: 85338a0ead89f729573af2b747d92d68544cff84
-config-catalog.zh.md: 8c74940b3aad350f720361e197a389055784b445
+config-catalog.md: 6188fec1cfe65369e59c10b851629122c393af1e
+config-catalog.zh.md: 1aefcaff17d272d4767a22a5ba72a7ab6dc0b914
diff --git a/docs/config-catalog.md b/docs/config-catalog.md
index 85338a0ead..6188fec1cf 100644
--- a/docs/config-catalog.md
+++ b/docs/config-catalog.md
@@ -1129,6 +1129,20 @@ export interface ReconnectConfig {
 
 Source: [`packages/mcp/mcp-client/src/index.ts:98`](../packages/mcp/mcp-client/src/index.ts)
 
+## `@deepseek-ai/dsh-message-feedback`
+
+Requires: `storageDomain` · `sessionPersistence` · `sessions`
+
+```ts config-catalog
+/** Required deployment policy for optional notes. */
+export interface Config {
+  /** Maximum UTF-8 byte length accepted for one note. */
+  readonly maxNoteBytes: number
+}
+```
+
+Source: [`packages/feedback/message-feedback/src/index.ts:49`](../packages/feedback/message-feedback/src/index.ts)
+
 ## `@deepseek-ai/dsh-permission`
 
 Requires: `bash` · `approval` · `sessions`
diff --git a/docs/config-catalog.zh.md b/docs/config-catalog.zh.md
index 8c74940b3a..1aefcaff17 100644
--- a/docs/config-catalog.zh.md
+++ b/docs/config-catalog.zh.md
@@ -1131,6 +1131,20 @@ export interface ReconnectConfig {
 
 来源：[`packages/mcp/mcp-client/src/index.ts:94`](../packages/mcp/mcp-client/src/index.ts)
 
+## `@deepseek-ai/dsh-message-feedback`
+
+需要：`storageDomain` · `sessionPersistence` · `sessions`
+
+```ts config-catalog
+/** Required deployment policy for optional notes. */
+export interface Config {
+  /** Maximum UTF-8 byte length accepted for one note. */
+  readonly maxNoteBytes: number
+}
+```
+
+来源：[`packages/feedback/message-feedback/src/index.ts:49`](../packages/feedback/message-feedback/src/index.ts)
+
 ## `@deepseek-ai/dsh-permission`
 
 需要：`bash` · `approval` · `sessions`
diff --git a/docs/module-graph.i18n.yaml b/docs/module-graph.i18n.yaml
index a44c4ac247..3f5820ec3e 100644
--- a/docs/module-graph.i18n.yaml
+++ b/docs/module-graph.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/module-graph.md
-module-graph.md: 2e7fdcc2028cf17d88f986efef3fb580839be18b
-module-graph.zh.md: 71bf4b361d8b639d54b91e6264f21f19df6fce13
+module-graph.md: 859a449f63bd36177a9c666ac9d894cb495b224f
+module-graph.zh.md: cedf087810cf309200368b43c6d53757426c58cd
diff --git a/docs/module-graph.md b/docs/module-graph.md
index 2e7fdcc202..859a449f63 100644
--- a/docs/module-graph.md
+++ b/docs/module-graph.md
@@ -201,6 +201,7 @@ flowchart TD
   end
   subgraph group_feedback["packages/feedback"]
     pkg_command_feedback["command-feedback"]
+    pkg_message_feedback["message-feedback"]
   end
   subgraph group_guard["packages/guard"]
     pkg_repeat_tool_guard["repeat-tool-guard"]
@@ -571,6 +572,13 @@ flowchart TD
   pkg_time_context --> pkg_agent
   pkg_time_context --> pkg_invariants
   pkg_time_context --> pkg_session
+  pkg_message_feedback --> pkg_brand
+  pkg_message_feedback --> pkg_invariants
+  pkg_message_feedback --> pkg_llm
+  pkg_message_feedback --> pkg_session
+  pkg_message_feedback --> pkg_session_persistence
+  pkg_message_feedback --> pkg_storage_domain
+  pkg_message_feedback --> pkg_type_meta
   pkg_host_apiproxy --> pkg_agent_presets
   pkg_host_apiproxy --> pkg_invariants
   pkg_host_directory_picker_auto --> pkg_host_directory_picker_browse
@@ -1349,6 +1357,7 @@ flowchart TD
 | [`spill-local`](../packages/spill/spill-local) | `spill` | [`invariants`](../packages/support/invariants), [`spill`](../packages/spill/spill) |
 | [`loader-smoke`](../packages/support/loader-smoke) | `support` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session) |
 | [`time-context`](../packages/context/time-context) | `context` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`session`](../packages/core/session) |
+| [`message-feedback`](../packages/feedback/message-feedback) | `feedback` | [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`session-persistence`](../packages/session/session-persistence), [`storage-domain`](../packages/storage/storage-domain), [`type-meta`](../packages/typert/type-meta) |
 | [`host-apiproxy`](../packages/host/apiproxy) | `host` | [`agent-presets`](../packages/preset/agent-presets), [`invariants`](../packages/support/invariants) |
 | [`host-directory-picker-auto`](../packages/host/directory-picker-auto) | `host` | [`host-directory-picker-browse`](../packages/host/directory-picker-browse), [`host-directory-picker-native`](../packages/host/directory-picker-native), [`host-webserver`](../packages/host/webserver), [`invariants`](../packages/support/invariants) |
 | [`commands`](../packages/interaction/commands) | `interaction` | [`agent`](../packages/core/agent), [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`scope`](../packages/core/scope), [`session`](../packages/core/session) |
diff --git a/docs/module-graph.zh.md b/docs/module-graph.zh.md
index 71bf4b361d..cedf087810 100644
--- a/docs/module-graph.zh.md
+++ b/docs/module-graph.zh.md
@@ -203,6 +203,7 @@ flowchart TD
   end
   subgraph group_feedback["packages/feedback"]
     pkg_command_feedback["command-feedback"]
+    pkg_message_feedback["message-feedback"]
   end
   subgraph group_guard["packages/guard"]
     pkg_repeat_tool_guard["repeat-tool-guard"]
@@ -573,6 +574,13 @@ flowchart TD
   pkg_time_context --> pkg_agent
   pkg_time_context --> pkg_invariants
   pkg_time_context --> pkg_session
+  pkg_message_feedback --> pkg_brand
+  pkg_message_feedback --> pkg_invariants
+  pkg_message_feedback --> pkg_llm
+  pkg_message_feedback --> pkg_session
+  pkg_message_feedback --> pkg_session_persistence
+  pkg_message_feedback --> pkg_storage_domain
+  pkg_message_feedback --> pkg_type_meta
   pkg_host_apiproxy --> pkg_agent_presets
   pkg_host_apiproxy --> pkg_invariants
   pkg_host_directory_picker_auto --> pkg_host_directory_picker_browse
@@ -1351,6 +1359,7 @@ flowchart TD
 | [`spill-local`](../packages/spill/spill-local) | `spill` | [`invariants`](../packages/support/invariants), [`spill`](../packages/spill/spill) |
 | [`loader-smoke`](../packages/support/loader-smoke) | `support` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session) |
 | [`time-context`](../packages/context/time-context) | `context` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`session`](../packages/core/session) |
+| [`message-feedback`](../packages/feedback/message-feedback) | `feedback` | [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`session-persistence`](../packages/session/session-persistence), [`storage-domain`](../packages/storage/storage-domain), [`type-meta`](../packages/typert/type-meta) |
 | [`host-apiproxy`](../packages/host/apiproxy) | `host` | [`agent-presets`](../packages/preset/agent-presets), [`invariants`](../packages/support/invariants) |
 | [`host-directory-picker-auto`](../packages/host/directory-picker-auto) | `host` | [`host-directory-picker-browse`](../packages/host/directory-picker-browse), [`host-directory-picker-native`](../packages/host/directory-picker-native), [`host-webserver`](../packages/host/webserver), [`invariants`](../packages/support/invariants) |
 | [`commands`](../packages/interaction/commands) | `interaction` | [`agent`](../packages/core/agent), [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`scope`](../packages/core/scope), [`session`](../packages/core/session) |
diff --git a/docs/subsystems/README.i18n.yaml b/docs/subsystems/README.i18n.yaml
index 9e578f7886..ebdccb923a 100644
--- a/docs/subsystems/README.i18n.yaml
+++ b/docs/subsystems/README.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/subsystems/README.md
-README.md: fddbf460c8e9e7c6f9ed1d3375bdabe65947661f
-README.zh.md: febc5a97426fef5ec4b2b80d9677957369994a3b
+README.md: 560851eeda607b762456fe20c874b4497704709f
+README.zh.md: 4acba4372e995b54a3bb326bec0cf9606f997773
diff --git a/docs/subsystems/README.md b/docs/subsystems/README.md
index fddbf460c8..560851eeda 100644
--- a/docs/subsystems/README.md
+++ b/docs/subsystems/README.md
@@ -18,6 +18,7 @@ One page per subsystem of the DeepSeek Harness: what it is, the data structures
 | [settings.md](settings.md) | the user-settings seam: `SettingsNamespace` registration, layered resolution (defaults → composition `base` → user document), owner scopes, hot commits |
 | [credentials.md](credentials.md) | the credential seam: `CredentialRef` references (never values) in configuration, per-operation resolution, UI-safe `CredentialInfo`, provider source layers |
 | [session-query.md](session-query.md) | logical records, bounded exact-event reads, relationship traces, semantic filters/documents, and full-text result pages |
+| [feedback.md](feedback.md) | lifecycle-bound per-message feedback records, optimistic versions, sidecar persistence, and the Host Remote contract |
 | [session-title.md](session-title.md) | durable title snapshots, cited source-message seqs, and the asynchronous provider contract |
 | [session-reference.md](session-reference.md) | structured cross-session references: `SessionReferenceInput`/`Candidate`, prepared message contexts, the stable error taxonomy |
 | [system-prompt.md](system-prompt.md) | per-assembly context, tool-provider results, prompt sections, and cooperative assembly |
diff --git a/docs/subsystems/README.zh.md b/docs/subsystems/README.zh.md
index febc5a9742..4acba4372e 100644
--- a/docs/subsystems/README.zh.md
+++ b/docs/subsystems/README.zh.md
@@ -18,6 +18,7 @@
 | [settings.md](settings.md) | 用户设置 seam：`SettingsNamespace` 注册、分层解析（默认值 → 组合 `base` → 用户文档）、owner scope、热提交 |
 | [credentials.md](credentials.md) | 凭据 seam：配置中的 `CredentialRef` 引用（绝不含值）、按操作解析、对 UI 安全的 `CredentialInfo`、provider 来源层 |
 | [session-query.md](session-query.md) | 逻辑记录、有界精确事件读取、关系追踪、语义筛选器/文档与全文检索结果页 |
+| [feedback.md](feedback.md) | 绑定生命周期的逐消息反馈记录、乐观版本、伴随记录持久化与 Host Remote 契约 |
 | [session-title.md](session-title.md) | 持久标题快照、被引用的来源消息 seq 与异步提供方约定 |
 | [session-reference.md](session-reference.md) | 结构化跨会话引用：`SessionReferenceInput`/`Candidate`、prepared 消息上下文、稳定错误分类 |
 | [system-prompt.md](system-prompt.md) | 逐次组装的上下文、工具提供方结果、提示词段落与协作式组装 |
diff --git a/docs/subsystems/feedback.i18n.yaml b/docs/subsystems/feedback.i18n.yaml
new file mode 100644
index 0000000000..f6de2debe9
--- /dev/null
+++ b/docs/subsystems/feedback.i18n.yaml
@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write docs/subsystems/feedback.md
+feedback.md: 76a29f7d6ba604fa07ed56429c9b066e22639671
+feedback.zh.md: 5a409832de68b6d0bc9688a907c0f22edd3b0a43
diff --git a/docs/subsystems/feedback.md b/docs/subsystems/feedback.md
new file mode 100644
index 0000000000..76a29f7d6b
--- /dev/null
+++ b/docs/subsystems/feedback.md
@@ -0,0 +1,256 @@
+# Message Feedback
+
+English | [中文](feedback.zh.md)
+
+[`@deepseek-ai/dsh-message-feedback`](../../packages/feedback/message-feedback) owns editable feedback for individual assistant messages. It is deliberately separate from the immutable Session-level `feedback/record` event: message feedback is a local storage-domain sidecar, not Session-log content or a projection, and it performs no telemetry handoff.
+
+Source: [`packages/feedback/message-feedback/src/types.ts`](../../packages/feedback/message-feedback/src/types.ts)
+
+## Public types
+
+```ts type-equiv
+/** Opaque compare-and-set token for one exact feedback item revision. */
+type MessageFeedbackVersion = Branded<'MessageFeedbackVersion'>
+```
+
+```ts type-equiv
+/** The human's overall judgment of one assistant message. */
+type MessageFeedbackRating = 'positive' | 'negative'
+```
+
+```ts type-equiv
+/** One current feedback value and its opaque mutation token. */
+interface MessageFeedbackItem {
+  /** Stable identity of the assistant message inside the owning Session. */
+  readonly messageId: MessageId
+  /** Overall positive or negative judgment. */
+  readonly rating: MessageFeedbackRating
+  /** Optional explanation, preserved verbatim after validation. */
+  readonly note?: string
+  /** Equality-only token replaced by every material create or update. */
+  readonly version: MessageFeedbackVersion
+  /** Host-assigned creation time in Unix epoch milliseconds. */
+  readonly createdAt: number
+  /** Host-assigned time of the most recent material update. */
+  readonly updatedAt: number
+}
+```
+
+```ts type-equiv
+/** Read all message feedback belonging to one persisted Session lifecycle. */
+interface MessageFeedbackListRequest {
+  /** Persisted Session whose sidecar should be read. */
+  readonly sessionId: SessionId
+}
+```
+
+```ts type-equiv
+/** Current feedback values for one Session, in first-creation order. */
+interface MessageFeedbackListValue {
+  /** Fresh immutable item snapshots. */
+  readonly items: readonly MessageFeedbackItem[]
+}
+```
+
+```ts type-equiv
+/** Create or replace feedback for one assistant message. */
+interface MessageFeedbackPutRequest {
+  /** Persisted Session that owns the target message. */
+  readonly sessionId: SessionId
+  /** Target assistant-message identity. */
+  readonly messageId: MessageId
+  /** Desired overall judgment. */
+  readonly rating: MessageFeedbackRating
+  /** Optional non-blank explanation. */
+  readonly note?: string
+  /** Observed item version, or `null` to require that no item exists. */
+  readonly ifVersion: MessageFeedbackVersion | null
+}
+```
+
+```ts type-equiv
+/** Delete feedback for one message after observing its current version. */
+interface MessageFeedbackDeleteRequest {
+  /** Persisted Session that owns the sidecar. */
+  readonly sessionId: SessionId
+  /** Message whose feedback should be absent after this operation. */
+  readonly messageId: MessageId
+  /** Observed item version; ignored when the item is already absent. */
+  readonly ifVersion: MessageFeedbackVersion
+}
+```
+
+```ts type-equiv
+/** Idempotent deletion acknowledgement. */
+interface MessageFeedbackDeleteValue {
+  /** Stable postcondition shared by the first deletion and every retry. */
+  readonly absent: true
+}
+```
+
+```ts type-equiv
+/** No persisted Session header exists for the requested id. */
+interface MessageFeedbackSessionNotFound {
+  readonly code: 'session-not-found'
+  readonly sessionId: SessionId
+}
+```
+
+```ts type-equiv
+/** The id does not name a derived, append-origin assistant message. */
+interface MessageFeedbackTargetNotFound {
+  readonly code: 'target-not-found'
+  readonly sessionId: SessionId
+  readonly messageId: MessageId
+}
+```
+
+```ts type-equiv
+/** A material mutation did not match the addressed item's current version. */
+interface MessageFeedbackVersionConflict {
+  readonly code: 'version-conflict'
+  /** Authoritative current item, or `null` when it does not exist. */
+  readonly current: MessageFeedbackItem | null
+}
+```
+
+```ts type-equiv
+/** A supplied note contains no non-whitespace character. */
+interface MessageFeedbackNoteBlank {
+  readonly code: 'note-blank'
+}
+```
+
+```ts type-equiv
+/** A supplied note exceeds the configured UTF-8 byte limit. */
+interface MessageFeedbackNoteTooLarge {
+  readonly code: 'note-too-large'
+  readonly maxBytes: number
+  readonly actualBytes: number
+}
+```
+
+```ts type-equiv
+/** Failures shared by the public message-feedback operations. */
+type MessageFeedbackFailure =
+  | MessageFeedbackSessionNotFound
+  | MessageFeedbackTargetNotFound
+  | MessageFeedbackVersionConflict
+  | MessageFeedbackNoteBlank
+  | MessageFeedbackNoteTooLarge
+```
+
+```ts type-equiv
+/** Successful public operation result. */
+interface MessageFeedbackSuccess<T> {
+  readonly ok: true
+  readonly value: T
+}
+```
+
+```ts type-equiv
+/** Rejected public operation result with a stable business failure. */
+interface MessageFeedbackRejected<E extends MessageFeedbackFailure> {
+  readonly ok: false
+  readonly error: E
+}
+```
+
+```ts type-equiv
+/** Result returned by the message-feedback `list` operation. */
+type MessageFeedbackListResult =
+  | MessageFeedbackSuccess<MessageFeedbackListValue>
+  | MessageFeedbackRejected<MessageFeedbackSessionNotFound>
+```
+
+```ts type-equiv
+/** Result returned by the message-feedback `put` operation. */
+type MessageFeedbackPutResult =
+  | MessageFeedbackSuccess<MessageFeedbackItem>
+  | MessageFeedbackRejected<
+    | MessageFeedbackSessionNotFound
+    | MessageFeedbackTargetNotFound
+    | MessageFeedbackVersionConflict
+    | MessageFeedbackNoteBlank
+    | MessageFeedbackNoteTooLarge
+  >
+```
+
+```ts type-equiv
+/** Result returned by the message-feedback `delete` operation. */
+type MessageFeedbackDeleteResult =
+  | MessageFeedbackSuccess<MessageFeedbackDeleteValue>
+  | MessageFeedbackRejected<MessageFeedbackSessionNotFound | MessageFeedbackVersionConflict>
+```
+
+## Data and concurrency
+
+One Session sidecar row contains its header identity `{createdAt, cwd}` and feedback items keyed by `MessageId`. Each item carries a positive or negative rating, an optional note, Host-assigned `createdAt`/`updatedAt` timestamps, and its own opaque version. Versions are compared only for equality and only against the addressed message; callers do not order or synthesize them.
+
+`put` uses strict optimistic concurrency: every request for an existing item must match its current `ifVersion`, including a no-op. A conflict returns the authoritative current item (or `null`), so a caller can reconcile a lost response or a concurrent edit without another read. Deleting an already absent item succeeds. A per-Session queue encloses inspection, read, conflict evaluation, and whole-row write, so these guarantees cover concurrent calls in one Host process.
+
+## Target and lifecycle authority
+
+`SessionPersistence.inspect()` supplies the target Session observation without publishing or resuming an Agent and without committing cold repair. A cold `listSnapshots()` preflight classifies definite absence; inspection failure for a catalogued Session propagates as infrastructure failure. `put` accepts only a non-empty, append-origin `assistant/message` with the requested `MessageId`; replacement-origin, usage-only empty, and non-assistant records are not feedback targets.
+
+The stored `{createdAt, cwd}` identity must match the inspected header. A mismatch is treated as absence: `list` returns no items, while `put` may replace the stale row with one bound to the current header identity. Forks use a new Session identity and receive no sidecar copy even when their seed contains the same messages.
+
+## Persistence and Remote contract
+
+The service stores whole Session rows in the `message_feedback` storage domain through `ctx.storageDomain`. Before `put` commits a row that references a target message, a matching live target passes through the canonical `ctx.sessions.flush` checkpoint; both live and cold paths are then physically read from sequence zero through `SessionPersistence.readFrom`. The resulting observation is revalidated before the sidecar write, so the durable target log always precedes its sidecar commit. `maxNoteBytes` is required and bounds note text by UTF-8 bytes; the Web Host composition sets `8192`. The package publishes the Host `messageFeedback.list`, `messageFeedback.put`, and `messageFeedback.delete` unary Remote contract through `GatewayService` and `@Remote`; the generated Cordis surface below is the method-level authority.
+
+Plugin disposal closes mutation admission, drains accepted per-Session queue work, and then closes the storage domain.
+
+## Boundaries and limitations
+
+- The client Remote aggregate mount and UI consumer are separately owned and deferred.
+- The mutation queue is process-local. Storage-domain has no cross-process conditional write, so multiple Host writers to one storage root have no compare-and-swap or lost-update guarantee.
+- Session persistence has no durable deletion surface. The service does not treat `session/disposed` or `host/session-removed` as deletion and therefore performs no fake cascade; orphan sidecar rows may remain after out-of-band log removal.
+- A request in the narrow interval after live detach but before the persistence catalog materializes the header can receive `session-not-found`; callers retry after retirement materialization.
+- Cold requests scan the complete Session snapshot catalog because persistence has no lookup-by-id metadata operation. One Session row also has no item-count or aggregate-byte cap; `maxNoteBytes` bounds only each note until a concrete consumer owns a row policy.
+- Header identity detects a reused id only when `{createdAt, cwd}` differs; a cloned log retaining the same header identity is indistinguishable by this contract.
+- The Host contract records no authenticated actor or audit identity and therefore assumes a trusted caller boundary.
+
+<!-- BEGIN GENERATED cordis-surface (gen-cordis-catalog.ts) — do not edit between markers -->
+
+<a id="cordis-surface"></a>
+
+## Cordis surface
+
+Generated from source by `scripts/gen-cordis-catalog.ts` (verified fresh by `pnpm run verify-cordis-catalog` in doc-sync; regenerate with `pnpm run gen-cordis-catalog`) — this section is byte-identical in both language sides of the page. Signature blocks use a `ts cordis-catalog` fence and keep the original source JSDoc; dispatch modes are defined in the [primer](../cordis-primer.md#dispatch-modes), and the framework-inherited `ctx` surface lives in [cordis-api/inherited.md](../cordis-api/inherited.md).
+
+<a id="ctxmessagefeedback--messagefeedbackservice"></a>
+
+### `ctx.messageFeedback` — `MessageFeedbackService`
+
+Storage-domain sidecar service. It inspects persisted Session history and never creates or resumes an Agent or Session.
+
+```ts cordis-catalog
+/**
+ * Read feedback belonging to the current persisted Session lifecycle.
+ * A stale row from a reused Session id is invisible.
+ * @param request - Session identity to inspect and list.
+ * @returns current immutable items or `session-not-found`.
+ */
+@Remote('list') async list(request: MessageFeedbackListRequest): Promise<MessageFeedbackListResult>
+
+/**
+ * Create or replace feedback for one derived append-origin assistant
+ * message. Every request must match the addressed item's current version;
+ * a matching no-op returns the stored item without changing its revision.
+ * @param request - target, desired value, and observed item version.
+ * @returns the committed item or an explicit business failure.
+ */
+@Remote('put') put(request: MessageFeedbackPutRequest): Promise<MessageFeedbackPutResult>
+
+/**
+ * Delete one feedback item. Absence is successful regardless of the
+ * supplied version; an existing item requires an exact version match.
+ * @param request - Session, message, and observed item version.
+ * @returns the stable absent postcondition, or an explicit failure.
+ */
+@Remote('delete') delete(request: MessageFeedbackDeleteRequest): Promise<MessageFeedbackDeleteResult>
+```
+
+Source: [`packages/feedback/message-feedback/src/index.ts:150`](../../packages/feedback/message-feedback/src/index.ts)
+<!-- END GENERATED cordis-surface -->
diff --git a/docs/subsystems/feedback.zh.md b/docs/subsystems/feedback.zh.md
new file mode 100644
index 0000000000..5a409832de
--- /dev/null
+++ b/docs/subsystems/feedback.zh.md
@@ -0,0 +1,256 @@
+# 消息反馈
+
+[English](feedback.md) | 中文
+
+[`@deepseek-ai/dsh-message-feedback`](../../packages/feedback/message-feedback)拥有针对单条 assistant 消息的可编辑反馈。它刻意与不可变的 Session 级 `feedback/record` 事件分离：message feedback 是本地 storage-domain 伴随记录（sidecar），不是 Session 日志内容或投影，也不执行遥测交接。
+
+来源：[`packages/feedback/message-feedback/src/types.ts`](../../packages/feedback/message-feedback/src/types.ts)
+
+## 公开类型
+
+```ts type-equiv
+/** Opaque compare-and-set token for one exact feedback item revision. */
+type MessageFeedbackVersion = Branded<'MessageFeedbackVersion'>
+```
+
+```ts type-equiv
+/** The human's overall judgment of one assistant message. */
+type MessageFeedbackRating = 'positive' | 'negative'
+```
+
+```ts type-equiv
+/** One current feedback value and its opaque mutation token. */
+interface MessageFeedbackItem {
+  /** Stable identity of the assistant message inside the owning Session. */
+  readonly messageId: MessageId
+  /** Overall positive or negative judgment. */
+  readonly rating: MessageFeedbackRating
+  /** Optional explanation, preserved verbatim after validation. */
+  readonly note?: string
+  /** Equality-only token replaced by every material create or update. */
+  readonly version: MessageFeedbackVersion
+  /** Host-assigned creation time in Unix epoch milliseconds. */
+  readonly createdAt: number
+  /** Host-assigned time of the most recent material update. */
+  readonly updatedAt: number
+}
+```
+
+```ts type-equiv
+/** Read all message feedback belonging to one persisted Session lifecycle. */
+interface MessageFeedbackListRequest {
+  /** Persisted Session whose sidecar should be read. */
+  readonly sessionId: SessionId
+}
+```
+
+```ts type-equiv
+/** Current feedback values for one Session, in first-creation order. */
+interface MessageFeedbackListValue {
+  /** Fresh immutable item snapshots. */
+  readonly items: readonly MessageFeedbackItem[]
+}
+```
+
+```ts type-equiv
+/** Create or replace feedback for one assistant message. */
+interface MessageFeedbackPutRequest {
+  /** Persisted Session that owns the target message. */
+  readonly sessionId: SessionId
+  /** Target assistant-message identity. */
+  readonly messageId: MessageId
+  /** Desired overall judgment. */
+  readonly rating: MessageFeedbackRating
+  /** Optional non-blank explanation. */
+  readonly note?: string
+  /** Observed item version, or `null` to require that no item exists. */
+  readonly ifVersion: MessageFeedbackVersion | null
+}
+```
+
+```ts type-equiv
+/** Delete feedback for one message after observing its current version. */
+interface MessageFeedbackDeleteRequest {
+  /** Persisted Session that owns the sidecar. */
+  readonly sessionId: SessionId
+  /** Message whose feedback should be absent after this operation. */
+  readonly messageId: MessageId
+  /** Observed item version; ignored when the item is already absent. */
+  readonly ifVersion: MessageFeedbackVersion
+}
+```
+
+```ts type-equiv
+/** Idempotent deletion acknowledgement. */
+interface MessageFeedbackDeleteValue {
+  /** Stable postcondition shared by the first deletion and every retry. */
+  readonly absent: true
+}
+```
+
+```ts type-equiv
+/** No persisted Session header exists for the requested id. */
+interface MessageFeedbackSessionNotFound {
+  readonly code: 'session-not-found'
+  readonly sessionId: SessionId
+}
+```
+
+```ts type-equiv
+/** The id does not name a derived, append-origin assistant message. */
+interface MessageFeedbackTargetNotFound {
+  readonly code: 'target-not-found'
+  readonly sessionId: SessionId
+  readonly messageId: MessageId
+}
+```
+
+```ts type-equiv
+/** A material mutation did not match the addressed item's current version. */
+interface MessageFeedbackVersionConflict {
+  readonly code: 'version-conflict'
+  /** Authoritative current item, or `null` when it does not exist. */
+  readonly current: MessageFeedbackItem | null
+}
+```
+
+```ts type-equiv
+/** A supplied note contains no non-whitespace character. */
+interface MessageFeedbackNoteBlank {
+  readonly code: 'note-blank'
+}
+```
+
+```ts type-equiv
+/** A supplied note exceeds the configured UTF-8 byte limit. */
+interface MessageFeedbackNoteTooLarge {
+  readonly code: 'note-too-large'
+  readonly maxBytes: number
+  readonly actualBytes: number
+}
+```
+
+```ts type-equiv
+/** Failures shared by the public message-feedback operations. */
+type MessageFeedbackFailure =
+  | MessageFeedbackSessionNotFound
+  | MessageFeedbackTargetNotFound
+  | MessageFeedbackVersionConflict
+  | MessageFeedbackNoteBlank
+  | MessageFeedbackNoteTooLarge
+```
+
+```ts type-equiv
+/** Successful public operation result. */
+interface MessageFeedbackSuccess<T> {
+  readonly ok: true
+  readonly value: T
+}
+```
+
+```ts type-equiv
+/** Rejected public operation result with a stable business failure. */
+interface MessageFeedbackRejected<E extends MessageFeedbackFailure> {
+  readonly ok: false
+  readonly error: E
+}
+```
+
+```ts type-equiv
+/** Result returned by the message-feedback `list` operation. */
+type MessageFeedbackListResult =
+  | MessageFeedbackSuccess<MessageFeedbackListValue>
+  | MessageFeedbackRejected<MessageFeedbackSessionNotFound>
+```
+
+```ts type-equiv
+/** Result returned by the message-feedback `put` operation. */
+type MessageFeedbackPutResult =
+  | MessageFeedbackSuccess<MessageFeedbackItem>
+  | MessageFeedbackRejected<
+    | MessageFeedbackSessionNotFound
+    | MessageFeedbackTargetNotFound
+    | MessageFeedbackVersionConflict
+    | MessageFeedbackNoteBlank
+    | MessageFeedbackNoteTooLarge
+  >
+```
+
+```ts type-equiv
+/** Result returned by the message-feedback `delete` operation. */
+type MessageFeedbackDeleteResult =
+  | MessageFeedbackSuccess<MessageFeedbackDeleteValue>
+  | MessageFeedbackRejected<MessageFeedbackSessionNotFound | MessageFeedbackVersionConflict>
+```
+
+## 数据与并发
+
+每个 Session 的一条伴随记录包含 header 身份 `{createdAt, cwd}` 和以 `MessageId` 为键的反馈条目。每个条目携带好评或差评、可选备注、Host 分配的 `createdAt`/`updatedAt` 时间戳及自己的 opaque version。version 只能用于相等比较，且只与目标消息比较；调用方不能排序或自行合成它。
+
+`put` 采用严格乐观并发：已有条目的每次请求都必须匹配当前 `ifVersion`，即使请求不会改变目标值。冲突会返回权威当前条目（不存在时为 `null`），因此调用方无需额外读取，即可协调丢失响应或并发编辑。删除已经不存在的条目同样成功。按 Session 划分的队列覆盖检查、读取、冲突判断与整行写入，因此这些保证适用于单个 Host 进程中的并发调用。
+
+## 目标与生命周期权威
+
+`SessionPersistence.inspect()` 提供目标 Session 的观测，且不会发布或恢复 Agent，也不会提交 cold repair。cold 路径先由 `listSnapshots()` 预检明确不存在；已进入目录的 Session 若检查失败，会按基础设施故障原样传播。`put` 只接受具有指定 `MessageId` 的非空、append-origin `assistant/message`；replacement-origin、仅承载 usage 的空记录和非 assistant 记录都不是反馈目标。
+
+存储的 `{createdAt, cwd}` 身份必须与检查所得 header 匹配。不匹配按不存在处理：`list` 返回空条目，`put` 则可用绑定当前 header 身份的新记录替换陈旧行。fork 使用新的 Session 身份，即使种子包含相同消息，也不获得伴随记录副本。
+
+## 持久化与 Remote 契约
+
+服务通过 `ctx.storageDomain` 在 `message_feedback` 存储域中保存完整 Session 行。`put` 提交引用目标消息的伴随记录前，身份匹配的 live 目标先经过权威 `ctx.sessions.flush` checkpoint；随后 live 与 cold 路径都会通过 `SessionPersistence.readFrom` 从序列零做物理复读。写入伴随记录前会再次校验所得观测，因此目标日志的持久提交始终先于其伴随记录。`maxNoteBytes` 为必填项，按 UTF-8 字节限制备注文本；Web Host 组合将其设为 `8192`。该包通过 `GatewayService` 与 `@Remote` 发布 Host `messageFeedback.list`、`messageFeedback.put` 和 `messageFeedback.delete` 一元 Remote 契约；下方生成的 Cordis surface 是方法级权威。
+
+Plugin disposal 会先关闭变更接纳，排空已进入各 Session 队列的工作，然后才关闭 storage domain。
+
+## 边界与限制
+
+- 客户端 Remote 聚合挂载与 UI 消费方由各自边界负责并保持延后。
+- 变更队列仅在进程内生效。storage-domain 没有跨进程条件写，因此多个 Host 写入同一存储根目录时，不提供 compare-and-swap 或防止丢失更新的保证。
+- Session persistence 没有持久删除接口。服务不把 `session/disposed` 或 `host/session-removed` 当作删除，因此不伪造级联；在带外移除日志后，孤儿伴随记录可能继续存在。
+- 请求若恰好落在 live detach 之后、persistence catalog 物化 header 之前的极短窗口，可能收到 `session-not-found`；调用方应在 retirement materialization 后重试。
+- 由于 persistence 没有按 id 读取元数据的操作，cold 请求会扫描完整的 Session snapshot 目录。单个 Session 行也没有条目数或聚合字节上限；在具体消费方拥有行策略之前，`maxNoteBytes` 只限制每条备注。
+- 只有 `{createdAt, cwd}` 不同时，header 身份才能识别复用的 id；本契约无法区分保留相同 header 身份的克隆日志。
+- Host 契约不记录已认证的 actor 或审计身份，因此假设调用方边界可信。
+
+<!-- BEGIN GENERATED cordis-surface (gen-cordis-catalog.ts) — do not edit between markers -->
+
+<a id="cordis-surface"></a>
+
+## Cordis surface
+
+Generated from source by `scripts/gen-cordis-catalog.ts` (verified fresh by `pnpm run verify-cordis-catalog` in doc-sync; regenerate with `pnpm run gen-cordis-catalog`) — this section is byte-identical in both language sides of the page. Signature blocks use a `ts cordis-catalog` fence and keep the original source JSDoc; dispatch modes are defined in the [primer](../cordis-primer.md#dispatch-modes), and the framework-inherited `ctx` surface lives in [cordis-api/inherited.md](../cordis-api/inherited.md).
+
+<a id="ctxmessagefeedback--messagefeedbackservice"></a>
+
+### `ctx.messageFeedback` — `MessageFeedbackService`
+
+Storage-domain sidecar service. It inspects persisted Session history and never creates or resumes an Agent or Session.
+
+```ts cordis-catalog
+/**
+ * Read feedback belonging to the current persisted Session lifecycle.
+ * A stale row from a reused Session id is invisible.
+ * @param request - Session identity to inspect and list.
+ * @returns current immutable items or `session-not-found`.
+ */
+@Remote('list') async list(request: MessageFeedbackListRequest): Promise<MessageFeedbackListResult>
+
+/**
+ * Create or replace feedback for one derived append-origin assistant
+ * message. Every request must match the addressed item's current version;
+ * a matching no-op returns the stored item without changing its revision.
+ * @param request - target, desired value, and observed item version.
+ * @returns the committed item or an explicit business failure.
+ */
+@Remote('put') put(request: MessageFeedbackPutRequest): Promise<MessageFeedbackPutResult>
+
+/**
+ * Delete one feedback item. Absence is successful regardless of the
+ * supplied version; an existing item requires an exact version match.
+ * @param request - Session, message, and observed item version.
+ * @returns the stable absent postcondition, or an explicit failure.
+ */
+@Remote('delete') delete(request: MessageFeedbackDeleteRequest): Promise<MessageFeedbackDeleteResult>
+```
+
+Source: [`packages/feedback/message-feedback/src/index.ts:150`](../../packages/feedback/message-feedback/src/index.ts)
+<!-- END GENERATED cordis-surface -->
diff --git a/packages/bundle/web-app/cordis.patch.yml b/packages/bundle/web-app/cordis.patch.yml
index 1c06b23157..cd6d752166 100644
--- a/packages/bundle/web-app/cordis.patch.yml
+++ b/packages/bundle/web-app/cordis.patch.yml
@@ -60,6 +60,11 @@
       config:
         backend: json
 
+    - id: message-feedback
+      name: '@deepseek-ai/dsh-message-feedback'
+      config:
+        maxNoteBytes: 8192
+
     - id: workspace
       name: '@deepseek-ai/dsh-workspace'
 
diff --git a/packages/bundle/web-app/package.json b/packages/bundle/web-app/package.json
index 3dcfc8ee6a..95e7428f0a 100644
--- a/packages/bundle/web-app/package.json
+++ b/packages/bundle/web-app/package.json
@@ -83,6 +83,7 @@
     "@deepseek-ai/dsh-host-directory-picker-browse": "workspace:^",
     "@deepseek-ai/dsh-host-directory-picker-native": "workspace:^",
     "@deepseek-ai/dsh-host-webserver": "workspace:^",
+    "@deepseek-ai/dsh-message-feedback": "workspace:^",
     "@deepseek-ai/dsh-session-projection-cache": "workspace:^",
     "@deepseek-ai/dsh-storage": "workspace:^",
     "@deepseek-ai/dsh-storage-domain": "workspace:^",
diff --git a/packages/feedback/README.i18n.yaml b/packages/feedback/README.i18n.yaml
index fce2946cff..bab1cf0db2 100644
--- a/packages/feedback/README.i18n.yaml
+++ b/packages/feedback/README.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/feedback/README.md
-README.md: af8e9d5c4903594299284d09f880aa8929f5e051
-README.zh.md: 9156ff1c8da8ed1128488fcacaf454425468163a
+README.md: 152db65bd7ac179bb8d475d446535734b9f8238e
+README.zh.md: 64202a3c4a0258f9b41a6cd96e7bbbf011d0338d
diff --git a/packages/feedback/README.md b/packages/feedback/README.md
index af8e9d5c49..152db65bd7 100644
--- a/packages/feedback/README.md
+++ b/packages/feedback/README.md
@@ -2,10 +2,13 @@
 
 English | [中文](README.zh.md)
 
-The feedback family lets a human record a remark about the session without acting on it. Feedback is durable session-log content, separate from the model conversation and from any policy that might later read it.
+The feedback family exposes two deliberately separate contracts: an immutable remark in the canonical Session log, and editable feedback attached to one assistant message in a local sidecar. Neither form enters the model conversation.
 
 | Package | Role | ctx key |
 |---|---|---|
 | `command-feedback/` | Trigger-independent `feedback/record` event plus the human-facing `/feedback` producer | — |
+| `message-feedback/` | Lifecycle-bound per-message rating/note sidecar plus Host `messageFeedback.list/put/delete` Remote contract | `messageFeedback` |
 
-A recorded remark is log-only: it never enters the model surface or derived history. When mounted, [`dsh-session-telemetry-otel`](../session/session-telemetry-otel) observes `feedback/record` to release a pending telemetry prefix or warn that disabled telemetry leaves the feedback local; capture itself remains independent of that policy.
+A command feedback remark is log-only: it never enters the model surface or derived history. When mounted, [`dsh-session-telemetry-otel`](../session/session-telemetry-otel) observes `feedback/record` to release a pending telemetry prefix or warn that disabled telemetry leaves the feedback local; capture itself remains independent of that policy.
+
+Message feedback is not a Session event or projection. It remains in the storage-domain sidecar and causes no telemetry handoff. The Host Remote contract ships with the service; the client Remote aggregate mount and UI consumer are separately owned and deferred.
diff --git a/packages/feedback/README.zh.md b/packages/feedback/README.zh.md
index 9156ff1c8d..64202a3c4a 100644
--- a/packages/feedback/README.zh.md
+++ b/packages/feedback/README.zh.md
@@ -2,10 +2,13 @@
 
 [English](README.md) | 中文
 
-反馈家族让人类记录对会话的评价，但不据此采取任何动作。反馈属于持久的会话日志内容，与模型对话以及后续可能读取它的任何策略相互独立。
+反馈家族公开两份刻意分离的契约：写入权威 Session 日志的不可变评价，以及挂在单条 assistant 消息上的可编辑本地伴随记录（sidecar）反馈。两者都不会进入模型对话。
 
 | 包 | 职责 | ctx 键 |
 |---|---|---|
 | `command-feedback/` | 与触发方式无关的 `feedback/record` 事件，以及面向用户的 `/feedback` 生产方 | 无 |
+| `message-feedback/` | 绑定生命周期的逐消息评分／备注伴随记录，以及 Host `messageFeedback.list/put/delete` Remote 契约 | `messageFeedback` |
 
-被记录的评价仅写入日志：它绝不会进入模型接口或派生历史。挂载后，[`dsh-session-telemetry-otel`](../session/session-telemetry-otel) 会观察 `feedback/record`，以释放待处理的遥测前缀，或在遥测已禁用时警告反馈将留在本地；采集本身与该策略相互独立。
+command feedback 评价仅写入日志：它绝不会进入模型接口或派生历史。挂载后，[`dsh-session-telemetry-otel`](../session/session-telemetry-otel) 会观察 `feedback/record`，以释放待处理的遥测前缀，或在遥测已禁用时警告反馈将留在本地；采集本身与该策略相互独立。
+
+message feedback 不是 Session 事件或投影。它只保留在 storage-domain 伴随记录中，不触发任何遥测交接。服务随附 Host Remote 契约；客户端 Remote 聚合挂载与 UI 消费方由各自边界负责，并保持延后。
diff --git a/packages/feedback/message-feedback/README.i18n.yaml b/packages/feedback/message-feedback/README.i18n.yaml
new file mode 100644
index 0000000000..edf8ec947b
--- /dev/null
+++ b/packages/feedback/message-feedback/README.i18n.yaml
@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write packages/feedback/message-feedback/README.md
+README.md: a9ebad25907e32435c8d2a65eb4b2cd9eaa89eeb
+README.zh.md: 29cbee0c1ec2ee810948d895c762d2e6320e9b66
diff --git a/packages/feedback/message-feedback/README.md b/packages/feedback/message-feedback/README.md
new file mode 100644
index 0000000000..a9ebad2590
--- /dev/null
+++ b/packages/feedback/message-feedback/README.md
@@ -0,0 +1,84 @@
+# @deepseek-ai/dsh-message-feedback
+
+English | [中文](README.zh.md)
+
+Host-owned editable feedback for one finalized assistant message. The package registers `ctx.messageFeedback`, persists one lifecycle-bound sidecar row per Session in storage-domain, and publishes the Host `messageFeedback.list`, `messageFeedback.put`, and `messageFeedback.delete` unary Remote contract. It is separate from the immutable Session-level `feedback/record` event and performs no telemetry handoff. The [message-feedback sidecar Agent Note](../../../.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.md) owns the design boundary.
+
+Public request, value, version, and failure types are exported from the package root and `@deepseek-ai/dsh-message-feedback/types`; [`src/types.ts`](src/types.ts) is their source.
+
+## Configuration
+
+| key | meaning |
+|---|---|
+| `maxNoteBytes` | Required positive safe integer: maximum UTF-8 byte length of one optional note. |
+
+Notes must contain at least one non-whitespace character, but accepted text is stored verbatim rather than trimmed. Omitting `note` means the desired value has no note, so a version-matched material `put` clears an existing note. Note validation precedes Session lookup and can therefore return `note-blank` or `note-too-large` for a missing Session without touching persistence.
+
+```yaml
+- id: message-feedback
+  name: '@deepseek-ai/dsh-message-feedback'
+  config:
+    maxNoteBytes: 8192
+```
+
+The service injects `storageDomain`, `sessionPersistence`, and `sessions`. Its durable domain is `message_feedback`, with one `sessions` table row per `SessionId`.
+
+## Data, lifecycle, and durability
+
+`MessageFeedbackItem` contains `messageId`, `rating: 'positive' | 'negative'`, optional `note`, an opaque equality-only `version`, and Host-assigned `createdAt`/`updatedAt` Unix-millisecond timestamps. A material update preserves `createdAt`, replaces `version`, and keeps `updatedAt` from moving backward. `list` returns fresh immutable snapshots in first-creation order; updating an item retains its place, while deleting and later recreating it appends a new item.
+
+Each stored row carries the inspected Session header identity `{createdAt, cwd}`. A mismatch is treated as absence: `list` returns an empty `items` array, `delete` returns the absent postcondition, and `put` may replace the stale row with one bound to the current identity. This fences a reused `SessionId` when its header identity differs. Forks use a distinct Session identity and receive no feedback-row copy.
+
+`SessionPersistence.inspect()` supplies a cold-safe observation without publishing or resuming an Agent and without committing cold repair. For a Session without a live owner, `listSnapshots()` first decides definite absence; an `inspect()` failure for a catalogued Session remains an infrastructure failure rather than being guessed into `session-not-found`. `put` accepts only a non-empty, append-origin `assistant/message` with the requested `MessageId`; replacement-origin messages, empty usage-only assistant records, and non-assistant records return `target-not-found`.
+
+After initial validation, `put` establishes a durability barrier before writing the sidecar. A matching live Session commits through the canonical `ctx.sessions.flush` checkpoint, then both live and cold paths are physically read from sequence zero through `SessionPersistence.readFrom`. The resulting observation's header identity and target are validated again. A missing flush participant, changed identity, vanished target, or physical-read failure prevents the sidecar commit, so durable feedback never precedes the durable target message.
+
+Message feedback is not Session-log content or a Session projection. It emits no `feedback/record` event, does not enter model history, and does not trigger `FEEDBACK_ONLY` telemetry release.
+
+## Service and Host Remote contract
+
+The same three `MessageFeedbackService` methods are published by `GatewayService` and `@Remote`; the Host endpoint names are `messageFeedback.list`, `messageFeedback.put`, and `messageFeedback.delete`. Every method returns a discriminated business union: `{ ok: true, value }` or `{ ok: false, error }`. Operational storage, corruption, or missing-durability-listener failures reject instead of being mislabeled as business errors.
+
+| Method | Request | Success `value` | Rejected `error.code` |
+|---|---|---|---|
+| `list` | `MessageFeedbackListRequest { sessionId }` | `MessageFeedbackListValue { items }` | `session-not-found` |
+| `put` | `MessageFeedbackPutRequest { sessionId, messageId, rating, note?, ifVersion }` | committed `MessageFeedbackItem` | `session-not-found`, `target-not-found`, `version-conflict`, `note-blank`, `note-too-large` |
+| `delete` | `MessageFeedbackDeleteRequest { sessionId, messageId, ifVersion }` | `MessageFeedbackDeleteValue { absent: true }` | `session-not-found`, `version-conflict` |
+
+`MessageFeedbackVersionConflict` returns the authoritative `current` item, or `null` when no item exists. This lets a caller reconcile the current rating, note, and version without a second `list` request. `MessageFeedbackNoteTooLarge` returns both `maxBytes` and `actualBytes`. The Client Remote aggregate does not mount the generated client contribution yet; Host callers can use the service/Remote contract without that client assembly.
+
+## Compare-and-set and idempotency
+
+`ifVersion: null` requests creation only; every request for an existing item requires its exact current version, including a no-op whose desired value already matches. The check is per message rather than per Session, so changing one item does not conflict with another. Every material create or update assigns a fresh opaque UUID token, preventing stale writes from crossing an ABA value cycle.
+
+A matching-version no-op returns the already stored item with unchanged version and timestamps. After a lost success response, a retry with the old token receives `version-conflict.current`; the caller can compare that authoritative item with its desired value without an extra read. `delete` ignores `ifVersion` when the item is already absent and always returns the stable `{ absent: true }` postcondition after success.
+
+A per-Session promise queue encloses inspection, durability validation, sidecar read, comparison, and whole-row write. These semantics serialize concurrent mutations through one service instance; storage-domain itself has no cross-process conditional write.
+
+Plugin disposal closes mutation admission, drains every operation already accepted into the per-Session queues, and only then closes the storage domain. A mutation submitted after disposal begins rejects as a lifecycle failure instead of entering a closing domain.
+
+## Model Experience
+
+### Local message-feedback state
+
+#### What the model sees
+
+Nothing. `ctx.messageFeedback` registers no tool, prompt section, model-facing context, or Session event; feedback stays in a Host-owned sidecar unless a separately documented Consumer explicitly exposes it.
+
+#### Token effect
+
+Zero. No request, result, rating, note, timestamp, or failure from this package enters a model request.
+
+#### KV Cache effect
+
+Independent. Listing or mutating message feedback does not touch a model request prefix and cannot invalidate an otherwise reusable provider cache entry.
+
+## Known Limitations and Deferred Work
+
+- **Client aggregate and UI are absent** — the Host Remote contract ships, but the Client Remote aggregate contribution and any UI consumer are separately owned and deferred.
+- **Compare-and-set is single-process** — the per-Session queue serializes one service instance only; multiple Host processes writing one storage root can still lose updates because storage-domain exposes no cross-process conditional write.
+- **No durable Session deletion cascade** — Session persistence has no deletion surface, and `session/disposed`/`host/session-removed` mean detach rather than durable deletion. The service therefore retains empty rows and may leave orphan rows after out-of-band log removal instead of deleting valid feedback on detach.
+- **Detach/catalog retirement window** — a request in the narrow interval after live detach but before the persistence catalog materializes the header can receive `session-not-found`; callers retry after retirement materialization.
+- **Header identity is not a content fingerprint** — `{createdAt, cwd}` detects reuse only when those fields differ; a cloned log retaining the same header identity is indistinguishable.
+- **Trusted caller boundary** — `list`/`put`/`delete` carry no authenticated actor or audit identity. A deployment must expose the Host gateway only through its trusted or separately authenticated boundary until authorization and attribution are added.
+- **Catalog and row bounds** — a cold request scans the complete Session snapshot catalog because persistence has no lookup-by-id metadata operation. `maxNoteBytes` bounds one note, but the item count and aggregate retained bytes of one Session row are not capped; an indexed metadata read and deployment-owned row bound remain deferred until a concrete consumer defines their policy.
diff --git a/packages/feedback/message-feedback/README.zh.md b/packages/feedback/message-feedback/README.zh.md
new file mode 100644
index 0000000000..29cbee0c1e
--- /dev/null
+++ b/packages/feedback/message-feedback/README.zh.md
@@ -0,0 +1,84 @@
+# @deepseek-ai/dsh-message-feedback
+
+[English](README.md) | 中文
+
+本包提供由 Host 拥有、针对单条已完成 assistant 消息的可编辑反馈。它注册 `ctx.messageFeedback`，在 storage-domain 中为每个 Session 持久化一条绑定生命周期的伴随记录（sidecar），并发布 Host `messageFeedback.list`、`messageFeedback.put` 与 `messageFeedback.delete` 一元 Remote 契约。它与不可变的 Session 级 `feedback/record` 事件相互独立，不执行遥测交接。[消息反馈伴随记录 Agent Note](../../../.agents/notes/implemented/architecture/2026-08-10-message-feedback-sidecar.md)拥有其设计边界。
+
+公开的请求、值、版本与失败类型从包根入口及 `@deepseek-ai/dsh-message-feedback/types` 导出；其源码为 [`src/types.ts`](src/types.ts)。
+
+## 配置
+
+| 键 | 含义 |
+|---|---|
+| `maxNoteBytes` | 必填正 safe integer：一条可选备注的最大 UTF-8 字节长度。 |
+
+备注必须包含至少一个非空白字符，但通过校验的文本按原样存储，不会 trim。省略 `note` 表示目标值不含备注，因此 version 匹配的实质 `put` 会清除已有备注。备注校验早于 Session 查找，因此即使 Session 不存在，也可能在不访问持久化的情况下返回 `note-blank` 或 `note-too-large`。
+
+```yaml
+- id: message-feedback
+  name: '@deepseek-ai/dsh-message-feedback'
+  config:
+    maxNoteBytes: 8192
+```
+
+服务注入 `storageDomain`、`sessionPersistence` 与 `sessions`。其持久存储域为 `message_feedback`，其中 `sessions` 表按 `SessionId` 每个一行。
+
+## 数据、生命周期与持久性
+
+`MessageFeedbackItem` 包含 `messageId`、`rating: 'positive' | 'negative'`、可选 `note`、只能做相等比较的 opaque `version`，以及由 Host 分配、以 Unix 毫秒表示的 `createdAt`/`updatedAt` 时间戳。实质更新保留 `createdAt`、替换 `version`，并保证 `updatedAt` 不倒退。`list` 按首次创建顺序返回新的不可变快照；更新条目时保留其位置，删除后再创建则追加为新条目。
+
+每条存储行都携带检查所得 Session header 身份 `{createdAt, cwd}`。不匹配按不存在处理：`list` 返回空 `items` 数组，`delete` 返回已不存在的后置条件，`put` 可以用绑定当前身份的新行替换陈旧行。这会在复用的 `SessionId` 具有不同 header 身份时形成隔离。fork 使用独立的 Session 身份，不复制反馈伴随记录。
+
+`SessionPersistence.inspect()` 提供 cold-safe 观测，不发布或恢复 Agent，也不提交 cold repair。对于没有 live owner 的 Session，系统先用 `listSnapshots()` 判定明确不存在；已进入目录的 Session 若 `inspect()` 失败，仍属于基础设施故障，不会被猜测成 `session-not-found`。`put` 只接受具有指定 `MessageId` 的非空、append-origin `assistant/message`；replacement-origin 消息、仅承载 usage 的空 assistant 记录与非 assistant 记录都返回 `target-not-found`。
+
+初步校验后，`put` 在写入伴随记录前建立 durability barrier。身份匹配的 live Session 先通过权威 `ctx.sessions.flush` checkpoint 提交，随后 live 与 cold 路径都会通过 `SessionPersistence.readFrom` 从序列零做物理复读。之后再次校验所得观测的 header 身份与目标。缺少 flush 参与方、身份变化、目标消失或物理读取失败都会阻止伴随记录提交，因此持久反馈绝不会先于其持久目标消息。
+
+message feedback 不是 Session 日志内容或 Session 投影。它不发出 `feedback/record` 事件，不进入模型历史，也不触发 `FEEDBACK_ONLY` 遥测释放。
+
+## 服务与 Host Remote 契约
+
+`GatewayService` 与 `@Remote` 将 `MessageFeedbackService` 的同三个方法发布出去；Host endpoint 名称为 `messageFeedback.list`、`messageFeedback.put` 与 `messageFeedback.delete`。每个方法都返回判别式业务 union：`{ ok: true, value }` 或 `{ ok: false, error }`。存储、损坏或缺少 durability listener 等操作故障会产生 reject，不会被误标为业务错误。
+
+| 方法 | 请求 | 成功 `value` | 拒绝的 `error.code` |
+|---|---|---|---|
+| `list` | `MessageFeedbackListRequest { sessionId }` | `MessageFeedbackListValue { items }` | `session-not-found` |
+| `put` | `MessageFeedbackPutRequest { sessionId, messageId, rating, note?, ifVersion }` | 已提交的 `MessageFeedbackItem` | `session-not-found`、`target-not-found`、`version-conflict`、`note-blank`、`note-too-large` |
+| `delete` | `MessageFeedbackDeleteRequest { sessionId, messageId, ifVersion }` | `MessageFeedbackDeleteValue { absent: true }` | `session-not-found`、`version-conflict` |
+
+`MessageFeedbackVersionConflict` 返回权威 `current` 条目；条目不存在时为 `null`。调用方无需额外执行 `list`，即可协调当前 rating、note 与 version。`MessageFeedbackNoteTooLarge` 同时返回 `maxBytes` 与 `actualBytes`。客户端 Remote 聚合尚未挂载生成的客户端 contribution；Host 调用方无需该客户端组装即可使用 service/Remote 契约。
+
+## Compare-and-set 与幂等性
+
+`ifVersion: null` 表示仅当条目不存在时才创建；已有条目的每次请求都必须与其当前 version 完全一致，即使目标值已经相同、不会产生实质更新。检查按消息而非按 Session 进行，因此修改一个条目不会与另一个条目冲突。每次实质创建或更新都会分配新的 opaque UUID token，防止陈旧写入穿过 ABA 值循环。
+
+携带匹配 version 的无变化请求会返回已存条目，version 与时间戳均不变。成功响应丢失后，使用旧 token 重试会得到 `version-conflict.current`；调用方无需额外读取，即可把权威当前值与目标值比较。条目已不存在时，`delete` 忽略 `ifVersion`；成功后始终返回稳定的 `{ absent: true }` 后置条件。
+
+按 Session 划分的 promise 队列覆盖检查、持久性校验、伴随记录读取、比较与整行写入。这些语义会串行化经由同一服务实例的并发变更；storage-domain 自身没有跨进程条件写。
+
+Plugin disposal 会先关闭变更接纳，排空已进入各个 Session 队列的所有操作，然后才关闭 storage domain。disposal 开始后提交的变更会以生命周期故障拒绝，不会进入正在关闭的 domain。
+
+## 模型体验
+
+### 本地消息反馈状态
+
+#### 模型看到的内容
+
+无。`ctx.messageFeedback` 不注册工具、提示词段落、模型可见上下文或 Session 事件；除非另一个具有独立文档的 Consumer 显式公开反馈，否则它只留在 Host 拥有的伴随记录中。
+
+#### Token 影响
+
+为零。本包的请求、结果、评分、备注、时间戳或失败都不会进入模型请求。
+
+#### KV Cache 影响
+
+相互独立。读取或变更消息反馈不会触碰模型请求前缀，也不会使本可复用的提供方缓存条目失效。
+
+## 已知局限与延后工作
+
+- **缺少客户端聚合与 UI**——Host Remote 契约已经发布，但客户端 Remote 聚合 contribution 与任何 UI 消费方由各自边界负责并保持延后。
+- **Compare-and-set 仅限单进程**——按 Session 划分的队列只串行化一个服务实例；storage-domain 不提供跨进程条件写，因此多个 Host 进程写入同一存储根目录时仍可能丢失更新。
+- **没有持久 Session 删除级联**——Session persistence 没有删除接口，且 `session/disposed`/`host/session-removed` 表示 detach 而非持久删除。因此服务会保留空行，并可能在带外移除日志后留下孤儿行，而不会在 detach 时删除仍有效的反馈。
+- **Detach/catalog retirement 窗口**——请求若恰好落在 live detach 之后、persistence catalog 物化 header 之前的极短窗口，可能收到 `session-not-found`；调用方应在 retirement materialization 后重试。
+- **Header 身份不是内容指纹**——只有 `{createdAt, cwd}` 不同时才能识别复用；本契约无法区分保留相同 header 身份的克隆日志。
+- **调用方边界受信任**——`list`/`put`/`delete` 不携带已认证的 actor 或审计身份。在加入授权与归属信息前，部署方必须只通过受信任或另行认证的边界暴露 Host gateway。
+- **目录与行边界**——由于 persistence 没有按 id 读取元数据的操作，cold 请求会扫描完整的 Session snapshot 目录。`maxNoteBytes` 只限制单条备注，单个 Session 行的条目数和聚合保留字节尚无上限；按索引读取元数据和由部署决定的行边界，延后到具体消费方明确策略时处理。
diff --git a/packages/feedback/message-feedback/package.json b/packages/feedback/message-feedback/package.json
new file mode 100644
index 0000000000..fe0caa18fb
--- /dev/null
+++ b/packages/feedback/message-feedback/package.json
@@ -0,0 +1,82 @@
+{
+  "name": "@deepseek-ai/dsh-message-feedback",
+  "description": "Lifecycle-bound per-message rating and note sidecar for the DeepSeek Harness",
+  "version": "0.0.1-rc.1",
+  "publishConfig": {
+    "access": "restricted"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/deepseek-ai/deepseek-harness.git",
+    "directory": "packages/feedback/message-feedback"
+  },
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./invariant": {
+      "types": "./lib/types/invariant.d.ts",
+      "default": "./lib/invariant.js"
+    },
+    "./types": {
+      "types": "./lib/types/types.d.ts",
+      "default": "./lib/types/types.js"
+    },
+    "./typert": {
+      "types": "./lib/typert.host.d.ts",
+      "default": "./lib/typert.host.js"
+    },
+    "./remote": {
+      "types": "./lib/typert.remote-client.d.ts",
+      "default": "./lib/typert.remote-client.js"
+    },
+    "./src/*": "./src/*",
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/invariant.js",
+    "lib/types/**/*.js",
+    "lib/types/**/*.d.ts",
+    "lib/typert.host.js",
+    "lib/typert.host.d.ts",
+    "lib/typert.remote-client.js",
+    "lib/typert.remote-client.d.ts",
+    "lib/typert.remote-client.d.ts.map",
+    "src"
+  ],
+  "license": "BSD-3-Clause",
+  "peerDependencies": {
+    "@deepseek-ai/dsh-brand": "workspace:^",
+    "@deepseek-ai/dsh-invariants": "workspace:^",
+    "@deepseek-ai/dsh-llm": "workspace:^",
+    "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-session-persistence": "workspace:^",
+    "@deepseek-ai/dsh-storage-domain": "workspace:^",
+    "@deepseek-ai/dsh-type-meta": "workspace:^",
+    "@deepseek-ai/cordis": "workspace:^"
+  },
+  "dependencies": {
+    "@deepseek-ai/schemastery": "workspace:^",
+    "zod": "^4.4.3"
+  },
+  "devDependencies": {
+    "@deepseek-ai/cordis-plugin-include": "workspace:^",
+    "@deepseek-ai/cordis-plugin-loader": "workspace:^",
+    "@deepseek-ai/dsh-brand": "workspace:^",
+    "@deepseek-ai/dsh-invariants": "workspace:^",
+    "@deepseek-ai/dsh-llm": "workspace:^",
+    "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-session-persistence": "workspace:^",
+    "@deepseek-ai/dsh-session-persistence-jsonl": "workspace:^",
+    "@deepseek-ai/dsh-storage": "workspace:^",
+    "@deepseek-ai/dsh-storage-domain": "workspace:^",
+    "@deepseek-ai/dsh-storage-json": "workspace:^",
+    "@deepseek-ai/dsh-type-meta": "workspace:^",
+    "@deepseek-ai/cordis": "workspace:^"
+  }
+}
diff --git a/packages/feedback/message-feedback/src/index.ts b/packages/feedback/message-feedback/src/index.ts
new file mode 100644
index 0000000000..6126e837e1
--- /dev/null
+++ b/packages/feedback/message-feedback/src/index.ts
@@ -0,0 +1,383 @@
+/**
+ * Durable, lifecycle-bound feedback for finalized assistant messages.
+ * @module @deepseek-ai/dsh-message-feedback
+ */
+
+import { Buffer } from 'node:buffer'
+import { randomUUID } from 'node:crypto'
+import { Context, Service } from '@deepseek-ai/cordis'
+import s from '@deepseek-ai/schemastery'
+import { deriveEventMessage, isAppendSurfaceEvent } from '@deepseek-ai/dsh-session/surface'
+import type { SessionHeader, SessionId } from '@deepseek-ai/dsh-session/types'
+import type { SessionInspection } from '@deepseek-ai/dsh-session-persistence'
+import type { KvTable } from '@deepseek-ai/dsh-storage-domain'
+import { GatewayService, Remote } from '@deepseek-ai/dsh-type-meta'
+import { messageFeedbackDomainSpec } from './spec.ts'
+import type { MessageFeedbackRow, MessageFeedbackSessionIdentity } from './spec.ts'
+import type {
+  MessageFeedbackDeleteRequest,
+  MessageFeedbackDeleteResult,
+  MessageFeedbackDeleteValue,
+  MessageFeedbackFailure,
+  MessageFeedbackItem,
+  MessageFeedbackListRequest,
+  MessageFeedbackListResult,
+  MessageFeedbackListValue,
+  MessageFeedbackNoteBlank,
+  MessageFeedbackNoteTooLarge,
+  MessageFeedbackPutRequest,
+  MessageFeedbackPutResult,
+  MessageFeedbackRejected,
+  MessageFeedbackSessionNotFound,
+  MessageFeedbackSuccess,
+  MessageFeedbackVersion,
+  MessageFeedbackVersionConflict,
+} from './types.ts'
+
+export type * from './types.ts'
+export {
+  messageFeedbackDomainSpec,
+  messageFeedbackItemSchema,
+  messageFeedbackRatingSchema,
+  messageFeedbackRowSchema,
+  messageFeedbackSessionIdentitySchema,
+  messageFeedbackVersionSchema,
+} from './spec.ts'
+export type { MessageFeedbackRow, MessageFeedbackSessionIdentity } from './spec.ts'
+
+/** Required deployment policy for optional notes. */
+export interface Config {
+  /** Maximum UTF-8 byte length accepted for one note. */
+  readonly maxNoteBytes: number
+}
+
+declare module '@deepseek-ai/cordis' {
+  interface Context {
+    messageFeedback: MessageFeedbackService
+  }
+}
+
+/** Immutable empty list reused only as an input to caller-owned copying. */
+const EMPTY_ITEMS: readonly MessageFeedbackItem[] = Object.freeze([])
+
+/** Validate the one deployment-varying limit at the configuration boundary. */
+function resolveMaxNoteBytes(value: number): number {
+  if (!Number.isSafeInteger(value) || value < 1) {
+    throw new TypeError(
+      `message-feedback: maxNoteBytes must be a positive safe integer, got ${String(value)}`,
+    )
+  }
+  return value
+}
+
+/** Copy and freeze one item before it crosses the service boundary. */
+function snapshotItem(item: MessageFeedbackItem): MessageFeedbackItem {
+  return Object.freeze({
+    messageId: item.messageId,
+    rating: item.rating,
+    ...(item.note === undefined ? {} : { note: item.note }),
+    version: item.version,
+    createdAt: item.createdAt,
+    updatedAt: item.updatedAt,
+  })
+}
+
+/** Copy and freeze a list response. */
+function snapshotList(items: readonly MessageFeedbackItem[]): MessageFeedbackListValue {
+  return Object.freeze({ items: Object.freeze(items.map(snapshotItem)) })
+}
+
+/** Build a frozen success branch. */
+function success<T>(value: T): MessageFeedbackSuccess<T> {
+  return Object.freeze({ ok: true, value })
+}
+
+/** Build a frozen business-failure branch. */
+function rejected<E extends MessageFeedbackFailure>(error: E): MessageFeedbackRejected<E> {
+  return Object.freeze({ ok: false, error: Object.freeze(error) })
+}
+
+/** Project the Session fields that distinguish one persisted log lifecycle. */
+function identityOf(header: SessionHeader): MessageFeedbackSessionIdentity {
+  return Object.freeze({
+    createdAt: header.createdAt,
+    ...(header.cwd === undefined ? {} : { cwd: header.cwd }),
+  })
+}
+
+/** Whether a stored row belongs to the inspected Session lifecycle. */
+function sameIdentity(row: MessageFeedbackRow, header: SessionHeader): boolean {
+  return row.session.createdAt === header.createdAt && row.session.cwd === header.cwd
+}
+
+/** Whether two observations name the same persisted Session lifecycle. */
+function sameHeaderIdentity(left: SessionHeader, right: SessionHeader): boolean {
+  return left.id === right.id && left.createdAt === right.createdAt && left.cwd === right.cwd
+}
+
+/** Freeze the replacement row so storage-domain never exposes mutable aliases. */
+function rowSnapshot(
+  session: MessageFeedbackSessionIdentity,
+  items: readonly MessageFeedbackItem[],
+): MessageFeedbackRow {
+  const copiedItems = items.map(snapshotItem)
+  Object.freeze(copiedItems)
+  return Object.freeze({
+    session,
+    items: copiedItems,
+  })
+}
+
+/** Generate an opaque equality token for one material mutation. */
+function nextVersion(): MessageFeedbackVersion {
+  return randomUUID() as MessageFeedbackVersion
+}
+
+/** Session inspection result that keeps absence inside the business union. */
+type KnownSession =
+  | MessageFeedbackSuccess<SessionInspection>
+  | MessageFeedbackRejected<MessageFeedbackSessionNotFound>
+
+/** Validated note or one explicit request failure. */
+type ResolvedNote =
+  | MessageFeedbackSuccess<string | undefined>
+  | MessageFeedbackRejected<MessageFeedbackNoteBlank | MessageFeedbackNoteTooLarge>
+
+/**
+ * Storage-domain sidecar service. It inspects persisted Session history and
+ * never creates or resumes an Agent or Session.
+ */
+export class MessageFeedbackService extends GatewayService {
+  static inject = ['storageDomain', 'sessionPersistence', 'sessions']
+
+  /** Loader validation for the required note-size policy. */
+  static Config: s<Config> = s.object({
+    maxNoteBytes: s.number().step(1).min(1).required(),
+  })
+
+  private readonly maxNoteBytes: number
+  private table?: KvTable<SessionId, MessageFeedbackRow>
+  private readonly operationTails = new Map<SessionId, Promise<void>>()
+  private mutationAdmissionOpen = true
+
+  /**
+   * @param ctx - Host context carrying persistence and the storage-domain form.
+   * @param config - Required note-size policy.
+   */
+  constructor(ctx: Context, config: Config) {
+    super(ctx, 'messageFeedback')
+    this.maxNoteBytes = resolveMaxNoteBytes(config.maxNoteBytes)
+  }
+
+  /** Open and own the one message-feedback sidecar domain. */
+  protected async [Service.init](): Promise<void> {
+    const domain = await this.ctx.storageDomain.open(messageFeedbackDomainSpec)
+    this.ctx.effect(() => async () => {
+      this.mutationAdmissionOpen = false
+      await Promise.all(this.operationTails.values())
+      await domain.close()
+    }, 'message-feedback.domainClose')
+    this.table = domain.table('sessions')
+  }
+
+  /**
+   * Read feedback belonging to the current persisted Session lifecycle.
+   * A stale row from a reused Session id is invisible.
+   * @param request - Session identity to inspect and list.
+   * @returns current immutable items or `session-not-found`.
+   */
+  @Remote('list')
+  async list(request: MessageFeedbackListRequest): Promise<MessageFeedbackListResult> {
+    const known = await this.inspectSession(request.sessionId)
+    if (!known.ok) return known
+    const row = this.requireTable().get(request.sessionId)
+    const items = row !== undefined && sameIdentity(row, known.value.meta) ? row.items : EMPTY_ITEMS
+    return success(snapshotList(items))
+  }
+
+  /**
+   * Create or replace feedback for one derived append-origin assistant
+   * message. Every request must match the addressed item's current version;
+   * a matching no-op returns the stored item without changing its revision.
+   * @param request - target, desired value, and observed item version.
+   * @returns the committed item or an explicit business failure.
+   */
+  @Remote('put')
+  put(request: MessageFeedbackPutRequest): Promise<MessageFeedbackPutResult> {
+    const note = this.resolveNote(request.note)
+    if (!note.ok) return Promise.resolve(note)
+    return this.enqueue(request.sessionId, async () => {
+      const known = await this.inspectSession(request.sessionId)
+      if (!known.ok) return known
+      if (!this.hasFeedbackTarget(known.value, request.messageId)) {
+        return rejected({
+          code: 'target-not-found',
+          sessionId: request.sessionId,
+          messageId: request.messageId,
+        })
+      }
+
+      const durable = await this.ensureTargetDurable(known.value)
+      if (!sameHeaderIdentity(durable.meta, known.value.meta)
+        || !this.hasFeedbackTarget(durable, request.messageId)) {
+        return rejected({
+          code: 'target-not-found',
+          sessionId: request.sessionId,
+          messageId: request.messageId,
+        })
+      }
+
+      const table = this.requireTable()
+      const stored = table.get(request.sessionId)
+      const current = stored !== undefined && sameIdentity(stored, durable.meta) ? stored : undefined
+      const items = current?.items ?? EMPTY_ITEMS
+      const index = items.findIndex(item => item.messageId === request.messageId)
+      const existing = items[index]
+      if (request.ifVersion !== (existing?.version ?? null)) {
+        return rejected(this.versionConflict(existing ?? null))
+      }
+      if (existing !== undefined
+        && existing.rating === request.rating
+        && existing.note === note.value) {
+        return success(snapshotItem(existing))
+      }
+
+      const now = Date.now()
+      const item = snapshotItem({
+        messageId: request.messageId,
+        rating: request.rating,
+        ...(note.value === undefined ? {} : { note: note.value }),
+        version: nextVersion(),
+        createdAt: existing?.createdAt ?? now,
+        updatedAt: existing === undefined ? now : Math.max(now, existing.updatedAt),
+      })
+      const nextItems = [...items]
+      if (index === -1) nextItems.push(item)
+      else nextItems[index] = item
+      await table.put(
+        request.sessionId,
+        rowSnapshot(identityOf(durable.meta), nextItems),
+      )
+      return success(snapshotItem(item))
+    })
+  }
+
+  /**
+   * Delete one feedback item. Absence is successful regardless of the
+   * supplied version; an existing item requires an exact version match.
+   * @param request - Session, message, and observed item version.
+   * @returns the stable absent postcondition, or an explicit failure.
+   */
+  @Remote('delete')
+  delete(request: MessageFeedbackDeleteRequest): Promise<MessageFeedbackDeleteResult> {
+    return this.enqueue(request.sessionId, async () => {
+      const known = await this.inspectSession(request.sessionId)
+      if (!known.ok) return known
+
+      const table = this.requireTable()
+      const stored = table.get(request.sessionId)
+      const current = stored !== undefined && sameIdentity(stored, known.value.meta) ? stored : undefined
+      const items = current?.items ?? EMPTY_ITEMS
+      const existing = items.find(item => item.messageId === request.messageId)
+      if (existing === undefined) {
+        return success<MessageFeedbackDeleteValue>(Object.freeze({ absent: true }))
+      }
+      if (request.ifVersion !== existing.version) {
+        return rejected(this.versionConflict(existing))
+      }
+
+      await table.put(
+        request.sessionId,
+        rowSnapshot(identityOf(known.value.meta), items.filter(item => item !== existing)),
+      )
+      return success<MessageFeedbackDeleteValue>(Object.freeze({ absent: true }))
+    })
+  }
+
+  /**
+   * Resolve a live owner directly; otherwise use the storage catalog as the
+   * existence authority before inspecting the log. Inspection failures for a
+   * catalogued Session remain infrastructure failures rather than being
+   * guessed into the business `session-not-found` branch.
+   */
+  private async inspectSession(sessionId: SessionId): Promise<KnownSession> {
+    if (this.ctx.sessions.get(sessionId) === undefined) {
+      const snapshots = await this.ctx.sessionPersistence.listSnapshots()
+      if (!snapshots.some(snapshot => snapshot.header.id === sessionId)
+        && this.ctx.sessions.get(sessionId) === undefined) {
+        return rejected({ code: 'session-not-found', sessionId })
+      }
+    }
+    return success(await this.ctx.sessionPersistence.inspect(sessionId))
+  }
+
+  /** Require the exact finalized append-origin assistant message projection. */
+  private hasFeedbackTarget(inspection: SessionInspection, messageId: MessageFeedbackItem['messageId']): boolean {
+    return inspection.events.some((event) => {
+      if (event.type !== 'assistant/message' || !isAppendSurfaceEvent(event)) return false
+      const message = deriveEventMessage(event)
+      return message?.role === 'assistant' && message.id === messageId
+    })
+  }
+
+  /**
+   * Put the target log prefix behind a durability barrier before its sidecar.
+   * A live owner flushes through the SessionStore's canonical checkpoint; a
+   * cold owner is re-read from the physical durable prefix.
+   */
+  private async ensureTargetDurable(inspection: SessionInspection): Promise<SessionInspection> {
+    const live = this.ctx.sessions.get(inspection.meta.id)
+    if (live !== undefined && sameHeaderIdentity(live.header, inspection.meta)) {
+      if (!(await this.ctx.sessions.flush(live))) {
+        throw new Error(
+          `message-feedback: no durability listener participated for live session '${inspection.meta.id}'`,
+        )
+      }
+      return await this.ctx.sessionPersistence.readFrom(inspection.meta.id, 0)
+    }
+    return await this.ctx.sessionPersistence.readFrom(inspection.meta.id, 0)
+  }
+
+  /** Validate optional-note semantics and the configured complete UTF-8 byte bound. */
+  private resolveNote(note: string | undefined): ResolvedNote {
+    if (note === undefined) return success(undefined)
+    if (note.trim().length === 0) return rejected({ code: 'note-blank' })
+    const actualBytes = Buffer.byteLength(note, 'utf8')
+    if (actualBytes > this.maxNoteBytes) {
+      return rejected({ code: 'note-too-large', maxBytes: this.maxNoteBytes, actualBytes })
+    }
+    return success(note)
+  }
+
+  /** Return the authoritative item needed to reconcile one failed comparison. */
+  private versionConflict(current: MessageFeedbackItem | null): MessageFeedbackVersionConflict {
+    return {
+      code: 'version-conflict',
+      current: current === null ? null : snapshotItem(current),
+    }
+  }
+
+  /** Queue a complete read/compare/write mutation behind this Session's prior mutation. */
+  private enqueue<T>(sessionId: SessionId, operation: () => Promise<T>): Promise<T> {
+    if (!this.mutationAdmissionOpen) {
+      return Promise.reject(new Error('message-feedback: service is disposing'))
+    }
+    const previous = this.operationTails.get(sessionId) ?? Promise.resolve()
+    const result = previous.then(operation)
+    const tail = result.then(() => undefined, () => undefined)
+    this.operationTails.set(sessionId, tail)
+    return result.finally(() => {
+      if (this.operationTails.get(sessionId) === tail) this.operationTails.delete(sessionId)
+    })
+  }
+
+  /** Resolve the initialized durable table or fail a broken service lifecycle. */
+  private requireTable(): KvTable<SessionId, MessageFeedbackRow> {
+    if (this.table === undefined) {
+      throw new Error('message-feedback: durable domain is not initialized')
+    }
+    return this.table
+  }
+}
+
+export default MessageFeedbackService
diff --git a/packages/feedback/message-feedback/src/invariant.ts b/packages/feedback/message-feedback/src/invariant.ts
new file mode 100644
index 0000000000..5433f318f1
--- /dev/null
+++ b/packages/feedback/message-feedback/src/invariant.ts
@@ -0,0 +1,27 @@
+/** Package-owned invariant companion. @module @deepseek-ai/dsh-message-feedback/invariant */
+
+/* jscpd:ignore-start */
+import type { Context } from '@deepseek-ai/cordis'
+import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-message-feedback'
+
+/** Cordis companion plugin name. */
+export const name = 'message-feedback-invariant'
+/** Services required before the companion can reserve and check package ownership. */
+export const inject = ['invariants']
+
+/**
+ * No runtime invariant: the private typed writer owns current row mutations,
+ * the domain schema validates rows on reopen, and no second authority exists.
+ */
+const install: InvariantInstaller = Object.assign(() => {}, { inject: ['messageFeedback'] })
+
+/**
+ * Register this package's invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))
+/* jscpd:ignore-end */
diff --git a/packages/feedback/message-feedback/src/spec.ts b/packages/feedback/message-feedback/src/spec.ts
new file mode 100644
index 0000000000..d08a536d06
--- /dev/null
+++ b/packages/feedback/message-feedback/src/spec.ts
@@ -0,0 +1,90 @@
+/**
+ * Durable storage-domain declaration for lifecycle-bound message feedback.
+ * @module @deepseek-ai/dsh-message-feedback/src/spec
+ */
+
+import { z } from 'zod'
+import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
+import type { SessionId } from '@deepseek-ai/dsh-session/types'
+import { defineDomain, domainTable } from '@deepseek-ai/dsh-storage-domain'
+import type { MessageFeedbackItem, MessageFeedbackRating, MessageFeedbackVersion } from './types.ts'
+
+const nonNegativeSafeInteger = z.number().int().nonnegative().max(Number.MAX_SAFE_INTEGER)
+
+/** Runtime schema for the closed rating vocabulary. */
+export const messageFeedbackRatingSchema = z.union([
+  z.literal('positive'),
+  z.literal('negative'),
+]) satisfies z.ZodType<MessageFeedbackRating>
+
+/** Runtime schema for one opaque item version stored on disk. */
+export const messageFeedbackVersionSchema = z.uuid()
+  .transform(value => value as MessageFeedbackVersion)
+
+/** Runtime schema for one current feedback item. */
+// Zod infers transformed branded fields structurally, so it cannot name the
+// public interface even though every branded output is created below.
+export const messageFeedbackItemSchema = z.object({
+  messageId: z.string().min(1).transform(value => value as MessageId),
+  rating: messageFeedbackRatingSchema,
+  note: z.string().refine(note => note.trim().length > 0, {
+    message: 'message feedback note must contain a non-whitespace character',
+  }).optional(),
+  version: messageFeedbackVersionSchema,
+  createdAt: nonNegativeSafeInteger,
+  updatedAt: nonNegativeSafeInteger,
+}).refine(item => item.updatedAt >= item.createdAt, {
+  path: ['updatedAt'],
+  message: 'message feedback updatedAt must not precede createdAt',
+}) as unknown as z.ZodType<MessageFeedbackItem>
+
+/** Persisted Session fields that fence a sidecar row to one log lifecycle. */
+export const messageFeedbackSessionIdentitySchema = z.object({
+  createdAt: nonNegativeSafeInteger,
+  cwd: z.string().optional(),
+})
+
+/** Persisted lifecycle identity inferred from its durable schema. */
+export type MessageFeedbackSessionIdentity = z.infer<typeof messageFeedbackSessionIdentitySchema>
+
+/**
+ * One whole-Session sidecar. Duplicate message ids would make item lookup
+ * ambiguous; duplicate versions would break their independent identity.
+ */
+export const messageFeedbackRowSchema = z.object({
+  session: messageFeedbackSessionIdentitySchema,
+  items: z.array(messageFeedbackItemSchema),
+}).superRefine((row, ctx) => {
+  const messageIds = new Set<string>()
+  const versions = new Set<string>()
+  row.items.forEach((item, index) => {
+    if (messageIds.has(item.messageId)) {
+      ctx.addIssue({
+        code: 'custom',
+        path: ['items', index, 'messageId'],
+        message: `duplicate message feedback id '${item.messageId}'`,
+      })
+    }
+    messageIds.add(item.messageId)
+    if (versions.has(item.version)) {
+      ctx.addIssue({
+        code: 'custom',
+        path: ['items', index, 'version'],
+        message: `duplicate message feedback version '${item.version}'`,
+      })
+    }
+    versions.add(item.version)
+  })
+})
+
+/** Durable sidecar row inferred from {@link messageFeedbackRowSchema}. */
+export type MessageFeedbackRow = z.infer<typeof messageFeedbackRowSchema>
+
+/** One lifecycle-bound sidecar record per Session id. */
+export const messageFeedbackDomainSpec = defineDomain({
+  name: 'message_feedback',
+  version: 0,
+  tables: {
+    sessions: domainTable<SessionId, MessageFeedbackRow>(messageFeedbackRowSchema),
+  },
+})
diff --git a/packages/feedback/message-feedback/src/types.ts b/packages/feedback/message-feedback/src/types.ts
new file mode 100644
index 0000000000..0be57b17b4
--- /dev/null
+++ b/packages/feedback/message-feedback/src/types.ts
@@ -0,0 +1,147 @@
+/**
+ * Public request, value, and failure vocabulary for per-message feedback.
+ * This module contains types only so generated Remote clients can consume it
+ * without importing Host runtime code.
+ * @module @deepseek-ai/dsh-message-feedback/types
+ */
+
+import type { Branded } from '@deepseek-ai/dsh-brand'
+import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
+import type { SessionId } from '@deepseek-ai/dsh-session/types'
+
+/** Opaque compare-and-set token for one exact feedback item revision. */
+export type MessageFeedbackVersion = Branded<'MessageFeedbackVersion'>
+
+/** The human's overall judgment of one assistant message. */
+export type MessageFeedbackRating = 'positive' | 'negative'
+
+/** One current feedback value and its opaque mutation token. */
+export interface MessageFeedbackItem {
+  /** Stable identity of the assistant message inside the owning Session. */
+  readonly messageId: MessageId
+  /** Overall positive or negative judgment. */
+  readonly rating: MessageFeedbackRating
+  /** Optional explanation, preserved verbatim after validation. */
+  readonly note?: string
+  /** Equality-only token replaced by every material create or update. */
+  readonly version: MessageFeedbackVersion
+  /** Host-assigned creation time in Unix epoch milliseconds. */
+  readonly createdAt: number
+  /** Host-assigned time of the most recent material update. */
+  readonly updatedAt: number
+}
+
+/** Read all message feedback belonging to one persisted Session lifecycle. */
+export interface MessageFeedbackListRequest {
+  /** Persisted Session whose sidecar should be read. */
+  readonly sessionId: SessionId
+}
+
+/** Current feedback values for one Session, in first-creation order. */
+export interface MessageFeedbackListValue {
+  /** Fresh immutable item snapshots. */
+  readonly items: readonly MessageFeedbackItem[]
+}
+
+/** Create or replace feedback for one assistant message. */
+export interface MessageFeedbackPutRequest {
+  /** Persisted Session that owns the target message. */
+  readonly sessionId: SessionId
+  /** Target assistant-message identity. */
+  readonly messageId: MessageId
+  /** Desired overall judgment. */
+  readonly rating: MessageFeedbackRating
+  /** Optional non-blank explanation. */
+  readonly note?: string
+  /** Observed item version, or `null` to require that no item exists. */
+  readonly ifVersion: MessageFeedbackVersion | null
+}
+
+/** Delete feedback for one message after observing its current version. */
+export interface MessageFeedbackDeleteRequest {
+  /** Persisted Session that owns the sidecar. */
+  readonly sessionId: SessionId
+  /** Message whose feedback should be absent after this operation. */
+  readonly messageId: MessageId
+  /** Observed item version; ignored when the item is already absent. */
+  readonly ifVersion: MessageFeedbackVersion
+}
+
+/** Idempotent deletion acknowledgement. */
+export interface MessageFeedbackDeleteValue {
+  /** Stable postcondition shared by the first deletion and every retry. */
+  readonly absent: true
+}
+
+/** No persisted Session header exists for the requested id. */
+export interface MessageFeedbackSessionNotFound {
+  readonly code: 'session-not-found'
+  readonly sessionId: SessionId
+}
+
+/** The id does not name a derived, append-origin assistant message. */
+export interface MessageFeedbackTargetNotFound {
+  readonly code: 'target-not-found'
+  readonly sessionId: SessionId
+  readonly messageId: MessageId
+}
+
+/** A material mutation did not match the addressed item's current version. */
+export interface MessageFeedbackVersionConflict {
+  readonly code: 'version-conflict'
+  /** Authoritative current item, or `null` when it does not exist. */
+  readonly current: MessageFeedbackItem | null
+}
+
+/** A supplied note contains no non-whitespace character. */
+export interface MessageFeedbackNoteBlank {
+  readonly code: 'note-blank'
+}
+
+/** A supplied note exceeds the configured UTF-8 byte limit. */
+export interface MessageFeedbackNoteTooLarge {
+  readonly code: 'note-too-large'
+  readonly maxBytes: number
+  readonly actualBytes: number
+}
+
+/** Failures shared by the public message-feedback operations. */
+export type MessageFeedbackFailure =
+  | MessageFeedbackSessionNotFound
+  | MessageFeedbackTargetNotFound
+  | MessageFeedbackVersionConflict
+  | MessageFeedbackNoteBlank
+  | MessageFeedbackNoteTooLarge
+
+/** Successful public operation result. */
+export interface MessageFeedbackSuccess<T> {
+  readonly ok: true
+  readonly value: T
+}
+
+/** Rejected public operation result with a stable business failure. */
+export interface MessageFeedbackRejected<E extends MessageFeedbackFailure> {
+  readonly ok: false
+  readonly error: E
+}
+
+/** Result returned by the message-feedback `list` operation. */
+export type MessageFeedbackListResult =
+  | MessageFeedbackSuccess<MessageFeedbackListValue>
+  | MessageFeedbackRejected<MessageFeedbackSessionNotFound>
+
+/** Result returned by the message-feedback `put` operation. */
+export type MessageFeedbackPutResult =
+  | MessageFeedbackSuccess<MessageFeedbackItem>
+  | MessageFeedbackRejected<
+    | MessageFeedbackSessionNotFound
+    | MessageFeedbackTargetNotFound
+    | MessageFeedbackVersionConflict
+    | MessageFeedbackNoteBlank
+    | MessageFeedbackNoteTooLarge
+  >
+
+/** Result returned by the message-feedback `delete` operation. */
+export type MessageFeedbackDeleteResult =
+  | MessageFeedbackSuccess<MessageFeedbackDeleteValue>
+  | MessageFeedbackRejected<MessageFeedbackSessionNotFound | MessageFeedbackVersionConflict>
diff --git a/packages/feedback/message-feedback/tests/helpers.ts b/packages/feedback/message-feedback/tests/helpers.ts
new file mode 100644
index 0000000000..1dfaa24396
--- /dev/null
+++ b/packages/feedback/message-feedback/tests/helpers.ts
@@ -0,0 +1,213 @@
+import { mkdtemp, rm } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { Context } from '@deepseek-ai/cordis'
+import { createAssistantMessage, createUserMessage } from '@deepseek-ai/dsh-llm'
+import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
+import SessionStore, {
+  SESSION_FORMAT_VERSION,
+  Session,
+  SessionId,
+  type SessionEvent,
+  type SessionHeader,
+} from '@deepseek-ai/dsh-session'
+import SessionPersistence, {
+  SessionPersistenceRevision,
+  type SessionInspection,
+  type SessionLocation,
+  type SessionPersistenceSnapshot,
+} from '@deepseek-ai/dsh-session-persistence'
+import Storage from '@deepseek-ai/dsh-storage'
+import * as StorageDomain from '@deepseek-ai/dsh-storage-domain'
+import * as StorageJson from '@deepseek-ai/dsh-storage-json'
+import MessageFeedbackService from '../src/index.ts'
+
+export interface MessageFixture {
+  readonly session: Session
+  readonly userMessageId: MessageId
+  readonly assistantMessageIds: readonly [MessageId, MessageId]
+  readonly emptyAssistantMessageId: MessageId
+  readonly replacementAssistantMessageId: MessageId
+}
+
+/** Append one deterministic transcript surface used by target-validation tests. */
+export function appendMessageFixture(session: Session): Omit<MessageFixture, 'session'> {
+  session.append('turn/start', { turn: 1 })
+  session.append('step/start', { turn: 1, step: 1 })
+  const user = createUserMessage({
+    content: [{ type: 'text', text: 'Question' }],
+    source: { kind: 'user' },
+  })
+  session.append('user/message', user, { surfaceOp: 'append' })
+
+  const first = createAssistantMessage({
+    content: [{ type: 'text', text: 'First answer' }],
+    source: { provider: 'test', model: 'test' },
+  })
+  const firstEvent = session.append('assistant/message', {
+    turn: 1,
+    step: 1,
+    message: first,
+  }, { surfaceOp: 'append' })
+  const second = createAssistantMessage({
+    content: [{ type: 'text', text: 'Second answer' }],
+    source: { provider: 'test', model: 'test' },
+  })
+  session.append('assistant/message', {
+    turn: 1,
+    step: 1,
+    message: second,
+  }, { surfaceOp: 'append' })
+  const empty = createAssistantMessage({
+    content: [],
+    source: { provider: 'test', model: 'test' },
+  })
+  session.append('assistant/message', {
+    turn: 1,
+    step: 1,
+    message: empty,
+  }, { surfaceOp: 'append' })
+  session.append('step/end', { turn: 1, step: 1 })
+  session.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
+
+  const replacement = createAssistantMessage({
+    content: [{ type: 'text', text: 'Model-only replacement' }],
+    source: { provider: 'test', model: 'test' },
+  })
+  session.append('assistant/message', {
+    turn: 1,
+    step: 1,
+    message: replacement,
+  }, {
+    surfaceOp: { op: 'replace', start: firstEvent.seq, end: firstEvent.seq },
+    sourceEventSeqs: [firstEvent.seq],
+  })
+
+  return {
+    userMessageId: user.id,
+    assistantMessageIds: [first.id, second.id],
+    emptyAssistantMessageId: empty.id,
+    replacementAssistantMessageId: replacement.id,
+  }
+}
+
+/** Construct one cold persistence fixture without publishing a live Session. */
+export function messageFixture(
+  rawId: string,
+  options: { readonly createdAt?: number; readonly cwd?: string } = {},
+): MessageFixture {
+  const id = SessionId(rawId)
+  const header: SessionHeader = {
+    version: SESSION_FORMAT_VERSION,
+    id,
+    createdAt: options.createdAt ?? 1_700_000_000_000,
+    ...(options.cwd === undefined ? {} : { cwd: options.cwd }),
+  }
+  const session = Session.create(id, [], header)
+  return { session, ...appendMessageFixture(session) }
+}
+
+/** Minimal controllable persistence provider for service-level tests. */
+class TestPersistence extends SessionPersistence {
+  static inject = ['sessions']
+
+  readonly durable = new Map<SessionId, SessionInspection>()
+  readonly logical = new Map<SessionId, SessionInspection>()
+  inspectFailure: Error | undefined
+  inspectCalls = 0
+  readFromCalls = 0
+  onReadFrom: (() => void | Promise<void>) | undefined
+  onListSnapshots: (() => void | Promise<void>) | undefined
+
+  locate(_meta: SessionHeader): SessionLocation | undefined { return undefined }
+  create(_meta: SessionHeader): Promise<void> { return Promise.resolve() }
+  append(_id: SessionId, _events: readonly SessionEvent[]): Promise<void> { return Promise.resolve() }
+
+  load(id: SessionId): Promise<SessionInspection> {
+    return this.readFrom(id, 0)
+  }
+
+  inspect(id: SessionId): Promise<SessionInspection> {
+    this.inspectCalls += 1
+    if (this.inspectFailure !== undefined) return Promise.reject(this.inspectFailure)
+    const explicit = this.logical.get(id)
+    if (explicit !== undefined) return Promise.resolve(explicit)
+    const live = this.ctx.sessions.get(id)
+    if (live !== undefined) return Promise.resolve({ meta: live.header, events: live.events })
+    const stored = this.durable.get(id)
+    return stored === undefined
+      ? Promise.reject(new Error(`test persistence: session '${id}' not found`))
+      : Promise.resolve(stored)
+  }
+
+  async readFrom(
+    id: SessionId,
+    fromSeq: number,
+  ): Promise<{ meta: SessionHeader; events: SessionEvent[] }> {
+    this.readFromCalls += 1
+    await this.onReadFrom?.()
+    const stored = this.durable.get(id)
+    return stored === undefined
+      ? Promise.reject(new Error(`test persistence: session '${id}' not found`))
+      : { meta: stored.meta, events: stored.events.filter(event => event.seq >= fromSeq) }
+  }
+
+  list(): Promise<SessionHeader[]> {
+    return Promise.resolve([...this.durable.values()].map(value => value.meta))
+  }
+
+  async listSnapshots(): Promise<SessionPersistenceSnapshot[]> {
+    await this.onListSnapshots?.()
+    return [...this.durable.values()].map((value, index) => ({
+      header: value.meta,
+      revision: SessionPersistenceRevision(`test:${index}:${value.events.length}`),
+    }))
+  }
+
+  persist(session: Session): void {
+    this.durable.set(session.id, { meta: session.header, events: session.events })
+  }
+
+  setDurable(inspection: SessionInspection): void {
+    this.durable.set(inspection.meta.id, inspection)
+  }
+}
+
+export interface TestHarness {
+  readonly ctx: Context
+  readonly persistence: TestPersistence
+  readonly root: string
+  disposeFeedback(): Promise<void>
+  dispose(): Promise<void>
+}
+
+/** Compose the service over the real storage hub/domain/JSON backend. */
+export async function setupHarness(maxNoteBytes = 64): Promise<TestHarness> {
+  const root = await mkdtemp(join(tmpdir(), 'dsh-message-feedback-test-'))
+  const ctx = new Context()
+  let disposeFeedback: (() => Promise<void>) | undefined
+  try {
+    await ctx.plugin(SessionStore)
+    await ctx.plugin(TestPersistence)
+    await ctx.plugin(Storage)
+    await ctx.plugin(StorageJson, { root })
+    await ctx.plugin(StorageDomain, { backend: 'json' })
+    const feedbackFiber = await ctx.plugin(MessageFeedbackService, { maxNoteBytes })
+    disposeFeedback = feedbackFiber.dispose
+  } catch (error) {
+    await ctx.fiber.dispose()
+    await rm(root, { recursive: true, force: true })
+    throw error
+  }
+  if (disposeFeedback === undefined) throw new Error('message feedback test plugin did not load')
+  return {
+    ctx,
+    persistence: ctx.sessionPersistence as unknown as TestPersistence,
+    root,
+    disposeFeedback,
+    async dispose() {
+      await ctx.fiber.dispose()
+      await rm(root, { recursive: true, force: true })
+    },
+  }
+}
diff --git a/packages/feedback/message-feedback/tests/invariant.spec.ts b/packages/feedback/message-feedback/tests/invariant.spec.ts
new file mode 100644
index 0000000000..e88131e147
--- /dev/null
+++ b/packages/feedback/message-feedback/tests/invariant.spec.ts
@@ -0,0 +1,23 @@
+import { describe, expect, it } from 'vitest'
+import InvariantService from '@deepseek-ai/dsh-invariants'
+import * as MessageFeedbackInvariant from '../src/invariant.ts'
+import { setupHarness } from './helpers.ts'
+
+describe('message-feedback invariant companion', () => {
+  it('removes its registry contribution when its fiber is disposed (HMR safety)', async () => {
+    const harness = await setupHarness()
+    try {
+      await harness.ctx.plugin(InvariantService)
+      const fiber = await harness.ctx.plugin(MessageFeedbackInvariant)
+
+      expect(() => {
+        harness.ctx.invariants.register('@deepseek-ai/dsh-message-feedback', () => {})
+      }).toThrow(/already registered/u)
+
+      await fiber.dispose()
+      await expect(harness.ctx.plugin(MessageFeedbackInvariant).await()).resolves.toBeDefined()
+    } finally {
+      await harness.dispose()
+    }
+  })
+})
diff --git a/packages/feedback/message-feedback/tests/loader-composition.spec.ts b/packages/feedback/message-feedback/tests/loader-composition.spec.ts
new file mode 100644
index 0000000000..98a7f29243
--- /dev/null
+++ b/packages/feedback/message-feedback/tests/loader-composition.spec.ts
@@ -0,0 +1,115 @@
+import { mkdtemp, rm, writeFile } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { pathToFileURL } from 'node:url'
+import { afterEach, describe, expect, it } from 'vitest'
+import { Context } from '@deepseek-ai/cordis'
+import Include from '@deepseek-ai/cordis-plugin-include'
+import Loader from '@deepseek-ai/cordis-plugin-loader'
+import SessionStore, { SessionId } from '@deepseek-ai/dsh-session'
+import SessionPersistenceJsonl from '@deepseek-ai/dsh-session-persistence-jsonl'
+import Storage from '@deepseek-ai/dsh-storage'
+import * as StorageDomain from '@deepseek-ai/dsh-storage-domain'
+import * as StorageJson from '@deepseek-ai/dsh-storage-json'
+import { remoteMethods } from '@deepseek-ai/dsh-type-meta'
+import MessageFeedbackService from '../src/index.ts'
+import { appendMessageFixture } from './helpers.ts'
+
+let root: string | undefined
+const contexts: Context[] = []
+
+afterEach(async () => {
+  await Promise.all(contexts.splice(0).map(ctx => ctx.fiber.dispose()))
+  if (root !== undefined) await rm(root, { recursive: true, force: true })
+  root = undefined
+})
+async function loadComposition(configPath: string): Promise<Context> {
+  const ctx = new Context()
+  contexts.push(ctx)
+  ctx.baseUrl = pathToFileURL(root as string).href + '/'
+  await ctx.plugin(Loader)
+  ctx.loader.builtins.include = Include
+  const modules = new Map<string, unknown>([
+    ['@deepseek-ai/dsh-session', SessionStore],
+    ['@deepseek-ai/dsh-session-persistence-jsonl', SessionPersistenceJsonl],
+    ['@deepseek-ai/dsh-storage', Storage],
+    ['@deepseek-ai/dsh-storage-json', StorageJson],
+    ['@deepseek-ai/dsh-storage-domain', StorageDomain],
+    ['@deepseek-ai/dsh-message-feedback', MessageFeedbackService],
+  ])
+  ctx.loader.internal = {
+    version: 'v2',
+    async import(specifier: string) {
+      if (!modules.has(specifier)) throw new Error(`unexpected Loader import: ${specifier}`)
+      return modules.get(specifier)
+    },
+  } as unknown as NonNullable<typeof ctx.loader.internal>
+  await ctx.loader.create({
+    name: 'cordis:include',
+    config: { path: pathToFileURL(configPath).href },
+  })
+  await ctx.loader.await()
+  const unloaded = [...ctx.loader.entries()]
+    .filter(entry => entry.fiber === undefined && !entry.disabled)
+    .map(entry => entry.options.name)
+  expect(unloaded).toEqual([])
+  return ctx
+}
+
+describe('message feedback through a real Loader composition', () => {
+  it('persists a checkpointed target and its sidecar across a cold restart', async () => {
+    root = await mkdtemp(join(tmpdir(), 'dsh-message-feedback-loader-'))
+    const configPath = join(root, 'cordis.yml')
+    await writeFile(configPath, [
+      "- name: '@deepseek-ai/dsh-session'",
+      "- name: '@deepseek-ai/dsh-session-persistence-jsonl'",
+      '  config:',
+      `    root: ${JSON.stringify(join(root, 'sessions'))}`,
+      '    compression: none',
+      '    writeBatchMaxDelayMs: 1',
+      "- name: '@deepseek-ai/dsh-storage'",
+      "- name: '@deepseek-ai/dsh-storage-json'",
+      '  config:',
+      `    root: ${JSON.stringify(join(root, 'storage'))}`,
+      "- name: '@deepseek-ai/dsh-storage-domain'",
+      '  config:',
+      '    backend: json',
+      "- name: '@deepseek-ai/dsh-message-feedback'",
+      '  config:',
+      '    maxNoteBytes: 32',
+      '',
+    ].join('\n'))
+
+    const first = await loadComposition(configPath)
+    expect(first.messageFeedback.typertGateway.namespace).toBe('messageFeedback')
+    expect(remoteMethods(first.messageFeedback).map(marker => marker.method))
+      .toEqual(['list', 'put', 'delete'])
+
+    const session = first.sessions.create(SessionId('loader-feedback'), {
+      meta: { cwd: root },
+    })
+    const fixture = appendMessageFixture(session)
+    const put = await first.messageFeedback.put({
+      sessionId: session.id,
+      messageId: fixture.assistantMessageIds[0],
+      rating: 'positive',
+      note: 'survives restart',
+      ifVersion: null,
+    })
+    if (!put.ok) throw new Error(`expected put success, got ${put.error.code}`)
+    const durable = await first.sessionPersistence.readFrom(session.id, 0)
+    expect(durable.events.some(event =>
+      event.type === 'assistant/message'
+      && event.data.message.id === fixture.assistantMessageIds[0])).toBe(true)
+
+    await first.fiber.dispose()
+    contexts.splice(contexts.indexOf(first), 1)
+
+    const second = await loadComposition(configPath)
+    await expect(second.messageFeedback.list({ sessionId: session.id })).resolves.toEqual({
+      ok: true,
+      value: { items: [put.value] },
+    })
+    expect(second.sessions.get(session.id)).toBeUndefined()
+  })
+})
diff --git a/packages/feedback/message-feedback/tests/message-feedback.spec.ts b/packages/feedback/message-feedback/tests/message-feedback.spec.ts
new file mode 100644
index 0000000000..f4478ec202
--- /dev/null
+++ b/packages/feedback/message-feedback/tests/message-feedback.spec.ts
@@ -0,0 +1,655 @@
+import { randomUUID } from 'node:crypto'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { Context } from '@deepseek-ai/cordis'
+import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
+import { Session, SessionId } from '@deepseek-ai/dsh-session'
+import { remoteMethods } from '@deepseek-ai/dsh-type-meta'
+import MessageFeedbackService, { messageFeedbackRowSchema } from '../src/index.ts'
+import type {
+  MessageFeedbackItem,
+  MessageFeedbackVersion,
+} from '../src/index.ts'
+import {
+  appendMessageFixture,
+  messageFixture,
+  setupHarness,
+  type TestHarness,
+} from './helpers.ts'
+
+const harnesses: TestHarness[] = []
+
+async function harness(maxNoteBytes = 64): Promise<TestHarness> {
+  const value = await setupHarness(maxNoteBytes)
+  harnesses.push(value)
+  return value
+}
+
+afterEach(async () => {
+  vi.useRealTimers()
+  await Promise.all(harnesses.splice(0).map(value => value.dispose()))
+})
+
+function staleVersion(): MessageFeedbackVersion {
+  return randomUUID() as MessageFeedbackVersion
+}
+
+function expectItem(
+  result: Awaited<ReturnType<TestHarness['ctx']['messageFeedback']['put']>>,
+): MessageFeedbackItem {
+  if (!result.ok) throw new Error(`expected feedback item, got ${result.error.code}`)
+  return result.value
+}
+
+describe('MessageFeedbackService public contract', () => {
+  it('publishes the exact Gateway namespace and Remote method names', async () => {
+    const { ctx } = await harness()
+    const binding = ctx.messageFeedback.typertGateway
+    expect(binding.serviceKey).toBe('messageFeedback')
+    expect(binding.namespace).toBe('messageFeedback')
+    expect(remoteMethods(ctx.messageFeedback)).toEqual([
+      { method: 'list', invocation: { kind: 'direct' } },
+      { method: 'put', invocation: { kind: 'direct' } },
+      { method: 'delete', invocation: { kind: 'direct' } },
+    ])
+  })
+
+  it('returns session-not-found only for a definite persistence miss', async () => {
+    const { ctx, persistence } = await harness()
+    const missing = SessionId('missing-session')
+    await expect(ctx.messageFeedback.list({ sessionId: missing })).resolves.toEqual({
+      ok: false,
+      error: { code: 'session-not-found', sessionId: missing },
+    })
+
+    const fixture = messageFixture('corrupt-session')
+    persistence.setDurable({ meta: fixture.session.header, events: fixture.session.events })
+    const corruption = new Error('stored log checksum mismatch')
+    persistence.inspectFailure = corruption
+    await expect(ctx.messageFeedback.list({ sessionId: fixture.session.id })).rejects.toBe(corruption)
+  })
+
+  it('rechecks live ownership before returning a cold catalog miss', async () => {
+    const { ctx, persistence } = await harness()
+    const sessionId = SessionId('catalog-live-race')
+    const listed = Promise.withResolvers<undefined>()
+    const release = Promise.withResolvers<undefined>()
+    persistence.onListSnapshots = async () => {
+      listed.resolve(undefined)
+      await release.promise
+    }
+
+    const pending = ctx.messageFeedback.list({ sessionId })
+    await listed.promise
+    ctx.sessions.create(sessionId, { meta: { createdAt: 1_700_000_000_001 } })
+    release.resolve(undefined)
+
+    await expect(pending).resolves.toEqual({ ok: true, value: { items: [] } })
+    expect(persistence.inspectCalls).toBe(1)
+  })
+
+  it('returns session-not-found from mutations and conflicts on an observed version for an absent item', async () => {
+    const { ctx, persistence } = await harness()
+    const missing = SessionId('missing-mutations')
+    const missingMessage = 'missing-message' as MessageId
+    await expect(ctx.messageFeedback.put({
+      sessionId: missing,
+      messageId: missingMessage,
+      rating: 'positive',
+      ifVersion: null,
+    })).resolves.toEqual({
+      ok: false,
+      error: { code: 'session-not-found', sessionId: missing },
+    })
+    await expect(ctx.messageFeedback.delete({
+      sessionId: missing,
+      messageId: missingMessage,
+      ifVersion: staleVersion(),
+    })).resolves.toEqual({
+      ok: false,
+      error: { code: 'session-not-found', sessionId: missing },
+    })
+
+    const fixture = messageFixture('absent-version-conflict')
+    persistence.persist(fixture.session)
+    const expected = staleVersion()
+    await expect(ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId: fixture.assistantMessageIds[0],
+      rating: 'positive',
+      ifVersion: expected,
+    })).resolves.toEqual({
+      ok: false,
+      error: { code: 'version-conflict', current: null },
+    })
+  })
+
+  it('creates, updates, and retry-reads immutable items with monotonic Host times', async () => {
+    const { ctx, persistence } = await harness()
+    const fixture = messageFixture('timestamps')
+    persistence.persist(fixture.session)
+    const messageId = fixture.assistantMessageIds[0]
+
+    vi.useFakeTimers()
+    vi.setSystemTime(1_700_000_001_000)
+    const created = expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'positive',
+      note: '  exact prose  ',
+      ifVersion: null,
+    }))
+    expect(created).toMatchObject({
+      messageId,
+      rating: 'positive',
+      note: '  exact prose  ',
+      createdAt: 1_700_000_001_000,
+      updatedAt: 1_700_000_001_000,
+    })
+    expect(created.version).toMatch(/^[0-9a-f-]{36}$/u)
+    expect(Object.isFrozen(created)).toBe(true)
+
+    vi.setSystemTime(1_700_000_000_000)
+    const updated = expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'negative',
+      ifVersion: created.version,
+    }))
+    expect(updated).toMatchObject({
+      messageId,
+      rating: 'negative',
+      createdAt: created.createdAt,
+      updatedAt: created.updatedAt,
+    })
+    expect(updated.version).not.toBe(created.version)
+
+    const retry = expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'negative',
+      ifVersion: updated.version,
+    }))
+    expect(retry).toEqual(updated)
+
+    const listed = await ctx.messageFeedback.list({ sessionId: fixture.session.id })
+    if (!listed.ok) throw new Error(`expected list success, got ${listed.error.code}`)
+    expect(listed.value.items).toEqual([updated])
+    expect(listed.value.items[0]).not.toBe(updated)
+    expect(Object.isFrozen(listed.value)).toBe(true)
+    expect(Object.isFrozen(listed.value.items)).toBe(true)
+    expect(Object.isFrozen(listed.value.items[0])).toBe(true)
+  })
+
+  it('reports non-blank and complete UTF-8 byte limits without touching persistence', async () => {
+    const { ctx, persistence } = await harness(4)
+    const fixture = messageFixture('note-limits')
+    persistence.persist(fixture.session)
+    const messageId = fixture.assistantMessageIds[0]
+    const before = persistence.inspectCalls
+
+    await expect(ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'positive',
+      note: ' \n\t ',
+      ifVersion: null,
+    })).resolves.toEqual({ ok: false, error: { code: 'note-blank' } })
+    await expect(ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'positive',
+      note: 'ééé',
+      ifVersion: null,
+    })).resolves.toEqual({
+      ok: false,
+      error: { code: 'note-too-large', maxBytes: 4, actualBytes: 6 },
+    })
+    expect(persistence.inspectCalls).toBe(before)
+
+    expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'positive',
+      note: '😀',
+      ifVersion: null,
+    }))
+  })
+
+  it('accepts only non-empty append-origin assistant projections as targets', async () => {
+    const { ctx, persistence } = await harness()
+    const fixture = messageFixture('targets')
+    persistence.persist(fixture.session)
+    const rejectedTargets: MessageId[] = [
+      fixture.userMessageId,
+      fixture.emptyAssistantMessageId,
+      fixture.replacementAssistantMessageId,
+    ]
+    for (const messageId of rejectedTargets) {
+      await expect(ctx.messageFeedback.put({
+        sessionId: fixture.session.id,
+        messageId,
+        rating: 'positive',
+        ifVersion: null,
+      })).resolves.toEqual({
+        ok: false,
+        error: {
+          code: 'target-not-found',
+          sessionId: fixture.session.id,
+          messageId,
+        },
+      })
+    }
+    expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId: fixture.assistantMessageIds[0],
+      rating: 'positive',
+      ifVersion: null,
+    }))
+  })
+
+  it('fails invalid direct configuration and a read before domain initialization', async () => {
+    const invalidCtx = new Context()
+    expect(() => new MessageFeedbackService(invalidCtx, { maxNoteBytes: 0 }))
+      .toThrow(/positive safe integer/u)
+    await invalidCtx.fiber.dispose()
+
+    const fixture = messageFixture('uninitialized-domain')
+    const rawCtx = new Context()
+    rawCtx.provide('sessions', { get: () => undefined } as never)
+    rawCtx.provide('sessionPersistence', {
+      listSnapshots: () => Promise.resolve([{ header: fixture.session.header, revision: 'test' }]),
+      inspect: () => Promise.resolve({ meta: fixture.session.header, events: fixture.session.events }),
+    } as never)
+    const raw = new MessageFeedbackService(rawCtx, { maxNoteBytes: 1 })
+    await expect(raw.list({ sessionId: fixture.session.id }))
+      .rejects.toThrow(/durable domain is not initialized/u)
+    await rawCtx.fiber.dispose()
+  })
+
+  it('rejects durable rows with duplicate message ids or reused item versions', () => {
+    const version = staleVersion()
+    const duplicate = messageFeedbackRowSchema.safeParse({
+      session: { createdAt: 1 },
+      items: [
+        {
+          messageId: 'same-message',
+          rating: 'positive',
+          version,
+          createdAt: 1,
+          updatedAt: 1,
+        },
+        {
+          messageId: 'same-message',
+          rating: 'negative',
+          version,
+          createdAt: 1,
+          updatedAt: 1,
+        },
+      ],
+    })
+    expect(duplicate.success).toBe(false)
+    if (duplicate.success) throw new Error('expected duplicate row rejection')
+    expect(duplicate.error.issues.map(issue => issue.path.join('.')))
+      .toEqual(['items.1.messageId', 'items.1.version'])
+  })
+})
+
+describe('MessageFeedbackService item concurrency', () => {
+  it('serializes whole-row writes while keeping versions independent per message', async () => {
+    const { ctx, persistence } = await harness()
+    const fixture = messageFixture('concurrent-items')
+    persistence.persist(fixture.session)
+    const [firstId, secondId] = fixture.assistantMessageIds
+
+    const [firstResult, secondResult] = await Promise.all([
+      ctx.messageFeedback.put({
+        sessionId: fixture.session.id,
+        messageId: firstId,
+        rating: 'positive',
+        ifVersion: null,
+      }),
+      ctx.messageFeedback.put({
+        sessionId: fixture.session.id,
+        messageId: secondId,
+        rating: 'negative',
+        ifVersion: null,
+      }),
+    ])
+    const first = expectItem(firstResult)
+    const second = expectItem(secondResult)
+    const updated = expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId: firstId,
+      rating: 'negative',
+      note: 'changed',
+      ifVersion: first.version,
+    }))
+
+    await expect(ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId: firstId,
+      rating: 'positive',
+      note: 'stale change',
+      ifVersion: first.version,
+    })).resolves.toEqual({
+      ok: false,
+      error: { code: 'version-conflict', current: updated },
+    })
+
+    const listed = await ctx.messageFeedback.list({ sessionId: fixture.session.id })
+    if (!listed.ok) throw new Error(`expected list success, got ${listed.error.code}`)
+    expect(listed.value.items).toEqual([updated, second])
+    expect(listed.value.items[1]?.version).toBe(second.version)
+  })
+
+  it('rejects a stale put even when the current value has returned to the same state', async () => {
+    const { ctx, persistence } = await harness()
+    const fixture = messageFixture('put-aba')
+    persistence.persist(fixture.session)
+    const messageId = fixture.assistantMessageIds[0]
+    const first = expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'positive',
+      ifVersion: null,
+    }))
+    const second = expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'negative',
+      ifVersion: first.version,
+    }))
+    const current = expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'positive',
+      ifVersion: second.version,
+    }))
+
+    await expect(ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'positive',
+      ifVersion: first.version,
+    })).resolves.toEqual({
+      ok: false,
+      error: { code: 'version-conflict', current },
+    })
+  })
+
+  it('makes delete retries stable and prevents delete/recreate ABA', async () => {
+    const { ctx, persistence } = await harness()
+    const fixture = messageFixture('delete-aba')
+    persistence.persist(fixture.session)
+    const messageId = fixture.assistantMessageIds[0]
+    const created = expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'positive',
+      ifVersion: null,
+    }))
+
+    await expect(ctx.messageFeedback.delete({
+      sessionId: fixture.session.id,
+      messageId,
+      ifVersion: staleVersion(),
+    })).resolves.toEqual({
+      ok: false,
+      error: { code: 'version-conflict', current: created },
+    })
+    const request = {
+      sessionId: fixture.session.id,
+      messageId,
+      ifVersion: created.version,
+    }
+    await expect(ctx.messageFeedback.delete(request)).resolves.toEqual({
+      ok: true,
+      value: { absent: true },
+    })
+    await expect(ctx.messageFeedback.delete(request)).resolves.toEqual({
+      ok: true,
+      value: { absent: true },
+    })
+
+    const recreated = expectItem(await ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId,
+      rating: 'negative',
+      ifVersion: null,
+    }))
+    expect(recreated.version).not.toBe(created.version)
+    await expect(ctx.messageFeedback.delete(request)).resolves.toEqual({
+      ok: false,
+      error: { code: 'version-conflict', current: recreated },
+    })
+  })
+
+  it('fences a reused Session id and lets the new lifecycle start cleanly', async () => {
+    const { ctx, persistence } = await harness()
+    const old = messageFixture('reused-session', { createdAt: 10, cwd: '/old' })
+    persistence.persist(old.session)
+    const oldItem = expectItem(await ctx.messageFeedback.put({
+      sessionId: old.session.id,
+      messageId: old.assistantMessageIds[0],
+      rating: 'positive',
+      ifVersion: null,
+    }))
+
+    const replacement = Session.create(
+      old.session.id,
+      old.session.events,
+      { ...old.session.header, createdAt: 20, cwd: '/new' },
+    )
+    persistence.persist(replacement)
+    await expect(ctx.messageFeedback.list({ sessionId: replacement.id })).resolves.toEqual({
+      ok: true,
+      value: { items: [] },
+    })
+    await expect(ctx.messageFeedback.delete({
+      sessionId: replacement.id,
+      messageId: old.assistantMessageIds[0],
+      ifVersion: oldItem.version,
+    })).resolves.toEqual({ ok: true, value: { absent: true } })
+
+    const newItem = expectItem(await ctx.messageFeedback.put({
+      sessionId: replacement.id,
+      messageId: old.assistantMessageIds[0],
+      rating: 'negative',
+      ifVersion: null,
+    }))
+    expect(newItem.version).not.toBe(oldItem.version)
+  })
+
+  it('drains admitted mutations before domain close and rejects later admission', async () => {
+    const current = await harness()
+    const { ctx, persistence } = current
+    const fixture = messageFixture('dispose-quiescence')
+    persistence.persist(fixture.session)
+    const service = ctx.messageFeedback
+    const lifecycle = service as unknown as { readonly mutationAdmissionOpen: boolean }
+    const started = Promise.withResolvers<undefined>()
+    const release = Promise.withResolvers<undefined>()
+    let physicalReads = 0
+    let committed = 0
+    persistence.onReadFrom = async () => {
+      physicalReads += 1
+      if (physicalReads !== 1) return
+      started.resolve(undefined)
+      await release.promise
+    }
+    ctx.on('domain/changed', (change) => {
+      if (change.domain === 'message_feedback') committed += 1
+    })
+
+    const first = service.put({
+      sessionId: fixture.session.id,
+      messageId: fixture.assistantMessageIds[0],
+      rating: 'positive',
+      ifVersion: null,
+    })
+    await started.promise
+    const second = service.put({
+      sessionId: fixture.session.id,
+      messageId: fixture.assistantMessageIds[1],
+      rating: 'negative',
+      ifVersion: null,
+    })
+    const disposal = current.disposeFeedback()
+    await vi.waitFor(() => { expect(lifecycle.mutationAdmissionOpen).toBe(false) })
+
+    await expect(service.delete({
+      sessionId: fixture.session.id,
+      messageId: fixture.assistantMessageIds[0],
+      ifVersion: staleVersion(),
+    })).rejects.toThrow('message-feedback: service is disposing')
+    release.resolve(undefined)
+
+    expectItem(await first)
+    expectItem(await second)
+    await disposal
+    expect(physicalReads).toBe(2)
+    expect(committed).toBe(2)
+  })
+})
+
+describe('MessageFeedbackService durability ordering', () => {
+  it('rejects a logical target missing from the cold physical durable prefix', async () => {
+    const { ctx, persistence } = await harness()
+    const fixture = messageFixture('cold-prefix')
+    persistence.logical.set(fixture.session.id, {
+      meta: fixture.session.header,
+      events: fixture.session.events,
+    })
+    persistence.setDurable({ meta: fixture.session.header, events: [] })
+
+    await expect(ctx.messageFeedback.put({
+      sessionId: fixture.session.id,
+      messageId: fixture.assistantMessageIds[0],
+      rating: 'positive',
+      ifVersion: null,
+    })).resolves.toEqual({
+      ok: false,
+      error: {
+        code: 'target-not-found',
+        sessionId: fixture.session.id,
+        messageId: fixture.assistantMessageIds[0],
+      },
+    })
+    expect(persistence.readFromCalls).toBe(1)
+    await expect(ctx.messageFeedback.list({ sessionId: fixture.session.id })).resolves.toEqual({
+      ok: true,
+      value: { items: [] },
+    })
+  })
+
+  it('commits and physically verifies a live target checkpoint before the sidecar write', async () => {
+    const { ctx, persistence } = await harness()
+    const session = ctx.sessions.create(SessionId('live-checkpoint'), {
+      meta: { createdAt: 30, cwd: '/live' },
+    })
+    const fixture = appendMessageFixture(session)
+    const order: string[] = []
+    ctx.on('session/flush', (current) => {
+      order.push('session:durable')
+      persistence.persist(current)
+    })
+    ctx.on('domain/changed', (change) => {
+      if (change.domain === 'message_feedback') order.push('sidecar:durable')
+    })
+    persistence.onReadFrom = () => { order.push('session:verified') }
+
+    expectItem(await ctx.messageFeedback.put({
+      sessionId: session.id,
+      messageId: fixture.assistantMessageIds[0],
+      rating: 'positive',
+      ifVersion: null,
+    }))
+    expect(order).toEqual(['session:durable', 'session:verified', 'sidecar:durable'])
+    expect(persistence.readFromCalls).toBe(1)
+    expect(persistence.durable.get(session.id)?.events).toContainEqual(
+      expect.objectContaining({ type: 'assistant/message' }),
+    )
+  })
+
+  it('fails closed when a live checkpoint fails, has no participant, or is not physically durable', async () => {
+    const failed = await harness()
+    const failedSession = failed.ctx.sessions.create(SessionId('live-flush-failure'))
+    const failedFixture = appendMessageFixture(failedSession)
+    const diskFailure = new Error('disk unavailable')
+    failed.ctx.on('session/flush', () => { throw diskFailure })
+    await expect(failed.ctx.messageFeedback.put({
+      sessionId: failedSession.id,
+      messageId: failedFixture.assistantMessageIds[0],
+      rating: 'positive',
+      ifVersion: null,
+    })).rejects.toBe(diskFailure)
+    await expect(failed.ctx.messageFeedback.list({ sessionId: failedSession.id })).resolves.toEqual({
+      ok: true,
+      value: { items: [] },
+    })
+
+    const absent = await harness()
+    const absentSession = absent.ctx.sessions.create(SessionId('live-no-flush'))
+    const absentFixture = appendMessageFixture(absentSession)
+    await expect(absent.ctx.messageFeedback.put({
+      sessionId: absentSession.id,
+      messageId: absentFixture.assistantMessageIds[0],
+      rating: 'positive',
+      ifVersion: null,
+    })).rejects.toThrow(/no durability listener participated/u)
+    await expect(absent.ctx.messageFeedback.list({ sessionId: absentSession.id })).resolves.toEqual({
+      ok: true,
+      value: { items: [] },
+    })
+
+    const noDurability = await harness()
+    const unpersistedSession = noDurability.ctx.sessions.create(SessionId('live-unpersisted'))
+    const unpersistedFixture = appendMessageFixture(unpersistedSession)
+    noDurability.ctx.on('session/flush', () => {})
+    await expect(noDurability.ctx.messageFeedback.put({
+      sessionId: unpersistedSession.id,
+      messageId: unpersistedFixture.assistantMessageIds[0],
+      rating: 'positive',
+      ifVersion: null,
+    })).rejects.toThrow(/not found/u)
+    expect(noDurability.persistence.durable.has(unpersistedSession.id)).toBe(false)
+    await expect(noDurability.ctx.messageFeedback.list({ sessionId: unpersistedSession.id })).resolves.toEqual({
+      ok: true,
+      value: { items: [] },
+    })
+  })
+
+  it('finishes the captured live checkpoint when the Session detaches mid-flush', async () => {
+    const { ctx, persistence } = await harness()
+    const session = ctx.sessions.prepare(SessionId('detach-during-flush'), {
+      meta: { createdAt: 40, cwd: '/detach' },
+    })
+    const detach = ctx.sessions.enter(session)
+    ctx.sessions.announce(session)
+    const fixture = appendMessageFixture(session)
+    const started = Promise.withResolvers<undefined>()
+    const release = Promise.withResolvers<undefined>()
+    ctx.on('session/flush', async (current) => {
+      started.resolve(undefined)
+      await release.promise
+      persistence.persist(current)
+    })
+
+    const pending = ctx.messageFeedback.put({
+      sessionId: session.id,
+      messageId: fixture.assistantMessageIds[0],
+      rating: 'positive',
+      ifVersion: null,
+    })
+    await started.promise
+    detach()
+    expect(ctx.sessions.get(session.id)).toBeUndefined()
+    release.resolve(undefined)
+    expectItem(await pending)
+    expect(persistence.readFromCalls).toBe(1)
+    await expect(ctx.messageFeedback.list({ sessionId: session.id })).resolves.toMatchObject({
+      ok: true,
+      value: { items: [{ messageId: fixture.assistantMessageIds[0] }] },
+    })
+  })
+})
diff --git a/packages/feedback/message-feedback/tsconfig.json b/packages/feedback/message-feedback/tsconfig.json
new file mode 100644
index 0000000000..e406c4c00e
--- /dev/null
+++ b/packages/feedback/message-feedback/tsconfig.json
@@ -0,0 +1,45 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types"
+  },
+  "include": [
+    "src"
+  ],
+  "references": [
+    {
+      "path": "../../../vendor/cosmokit"
+    },
+    {
+      "path": "../../../vendor/cordis"
+    },
+    {
+      "path": "../../../vendor/schemastery"
+    },
+    {
+      "path": "../../util/brand"
+    },
+    {
+      "path": "../../llm/llm"
+    },
+    {
+      "path": "../../core/session"
+    },
+    {
+      "path": "../../session/session-persistence"
+    },
+    {
+      "path": "../../storage/storage"
+    },
+    {
+      "path": "../../storage/storage-domain"
+    },
+    {
+      "path": "../../typert/type-meta"
+    },
+    {
+      "path": "../../support/invariants"
+    }
+  ]
+}
diff --git a/packages/self-modification/tool-cordis/src/api-catalog.ts b/packages/self-modification/tool-cordis/src/api-catalog.ts
index 3052b6895d..732ab3fa00 100644
--- a/packages/self-modification/tool-cordis/src/api-catalog.ts
+++ b/packages/self-modification/tool-cordis/src/api-catalog.ts
@@ -586,6 +586,24 @@ export const SERVICE_API: readonly ServiceApiEntry[] = [
       },
     ],
   },
+  {
+    key: 'messageFeedback',
+    summary: 'Storage-domain sidecar service.',
+    methods: [
+      {
+        signature: '@Remote(\'list\') async list(request: MessageFeedbackListRequest): Promise<MessageFeedbackListResult>',
+        jsDoc: '/**\n * Read feedback belonging to the current persisted Session lifecycle.\n * A stale row from a reused Session id is invisible.\n * @param request - Session identity to inspect and list.\n * @returns current immutable items or `session-not-found`.\n */',
+      },
+      {
+        signature: '@Remote(\'put\') put(request: MessageFeedbackPutRequest): Promise<MessageFeedbackPutResult>',
+        jsDoc: '/**\n * Create or replace feedback for one derived append-origin assistant\n * message. Every request must match the addressed item\'s current version;\n * a matching no-op returns the stored item without changing its revision.\n * @param request - target, desired value, and observed item version.\n * @returns the committed item or an explicit business failure.\n */',
+      },
+      {
+        signature: '@Remote(\'delete\') delete(request: MessageFeedbackDeleteRequest): Promise<MessageFeedbackDeleteResult>',
+        jsDoc: '/**\n * Delete one feedback item. Absence is successful regardless of the\n * supplied version; an existing item requires an exact version match.\n * @param request - Session, message, and observed item version.\n * @returns the stable absent postcondition, or an explicit failure.\n */',
+      },
+    ],
+  },
   {
     key: 'permission',
     summary: 'Owns the deployment\'s permission presets and their write path.',
@@ -2335,6 +2353,82 @@ export const TYPE_API: readonly TypeApiEntry[] = [
     name: 'Message',
     declaration: 'export interface Message {\n    readonly id: MessageId;\n    readonly role: \'system\' | \'user\' | \'assistant\';\n    readonly content: ContentBlock[];\n    readonly source: MessageSource;\n}',
   },
+  {
+    name: 'MessageFeedbackDeleteRequest',
+    declaration: 'export interface MessageFeedbackDeleteRequest {\n    readonly sessionId: SessionId;\n    readonly messageId: MessageId;\n    readonly ifVersion: MessageFeedbackVersion;\n}',
+  },
+  {
+    name: 'MessageFeedbackDeleteResult',
+    declaration: 'export type MessageFeedbackDeleteResult = MessageFeedbackSuccess<MessageFeedbackDeleteValue> | MessageFeedbackRejected<MessageFeedbackSessionNotFound | MessageFeedbackVersionConflict>;',
+  },
+  {
+    name: 'MessageFeedbackDeleteValue',
+    declaration: 'export interface MessageFeedbackDeleteValue {\n    readonly absent: true;\n}',
+  },
+  {
+    name: 'MessageFeedbackFailure',
+    declaration: 'export type MessageFeedbackFailure = MessageFeedbackSessionNotFound | MessageFeedbackTargetNotFound | MessageFeedbackVersionConflict | MessageFeedbackNoteBlank | MessageFeedbackNoteTooLarge;',
+  },
+  {
+    name: 'MessageFeedbackItem',
+    declaration: 'export interface MessageFeedbackItem {\n    readonly messageId: MessageId;\n    readonly rating: MessageFeedbackRating;\n    readonly note?: string;\n    readonly version: MessageFeedbackVersion;\n    readonly createdAt: number;\n    readonly updatedAt: number;\n}',
+  },
+  {
+    name: 'MessageFeedbackListRequest',
+    declaration: 'export interface MessageFeedbackListRequest {\n    readonly sessionId: SessionId;\n}',
+  },
+  {
+    name: 'MessageFeedbackListResult',
+    declaration: 'export type MessageFeedbackListResult = MessageFeedbackSuccess<MessageFeedbackListValue> | MessageFeedbackRejected<MessageFeedbackSessionNotFound>;',
+  },
+  {
+    name: 'MessageFeedbackListValue',
+    declaration: 'export interface MessageFeedbackListValue {\n    readonly items: readonly MessageFeedbackItem[];\n}',
+  },
+  {
+    name: 'MessageFeedbackNoteBlank',
+    declaration: 'export interface MessageFeedbackNoteBlank {\n    readonly code: \'note-blank\';\n}',
+  },
+  {
+    name: 'MessageFeedbackNoteTooLarge',
+    declaration: 'export interface MessageFeedbackNoteTooLarge {\n    readonly code: \'note-too-large\';\n    readonly maxBytes: number;\n    readonly actualBytes: number;\n}',
+  },
+  {
+    name: 'MessageFeedbackPutRequest',
+    declaration: 'export interface MessageFeedbackPutRequest {\n    readonly sessionId: SessionId;\n    readonly messageId: MessageId;\n    readonly rating: MessageFeedbackRating;\n    readonly note?: string;\n    readonly ifVersion: MessageFeedbackVersion | null;\n}',
+  },
+  {
+    name: 'MessageFeedbackPutResult',
+    declaration: 'export type MessageFeedbackPutResult = MessageFeedbackSuccess<MessageFeedbackItem> | MessageFeedbackRejected<MessageFeedbackSessionNotFound | MessageFeedbackTargetNotFound | MessageFeedbackVersionConflict | MessageFeedbackNoteBlank | MessageFeedbackNoteTooLarge>;',
+  },
+  {
+    name: 'MessageFeedbackRating',
+    declaration: 'export type MessageFeedbackRating = \'positive\' | \'negative\';',
+  },
+  {
+    name: 'MessageFeedbackRejected',
+    declaration: 'export interface MessageFeedbackRejected<E extends MessageFeedbackFailure> {\n    readonly ok: false;\n    readonly error: E;\n}',
+  },
+  {
+    name: 'MessageFeedbackSessionNotFound',
+    declaration: 'export interface MessageFeedbackSessionNotFound {\n    readonly code: \'session-not-found\';\n    readonly sessionId: SessionId;\n}',
+  },
+  {
+    name: 'MessageFeedbackSuccess',
+    declaration: 'export interface MessageFeedbackSuccess<T> {\n    readonly ok: true;\n    readonly value: T;\n}',
+  },
+  {
+    name: 'MessageFeedbackTargetNotFound',
+    declaration: 'export interface MessageFeedbackTargetNotFound {\n    readonly code: \'target-not-found\';\n    readonly sessionId: SessionId;\n    readonly messageId: MessageId;\n}',
+  },
+  {
+    name: 'MessageFeedbackVersion',
+    declaration: 'export type MessageFeedbackVersion = Branded<\'MessageFeedbackVersion\'>;',
+  },
+  {
+    name: 'MessageFeedbackVersionConflict',
+    declaration: 'export interface MessageFeedbackVersionConflict {\n    readonly code: \'version-conflict\';\n    readonly current: MessageFeedbackItem | null;\n}',
+  },
   {
     name: 'MessageId',
     declaration: 'export type MessageId = Branded<\'MessageId\'>;',
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 495beb9e8b..a787f4c68e 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -1608,6 +1608,9 @@ importers:
       '@deepseek-ai/dsh-host-webserver':
         specifier: workspace:^
         version: link:../../host/webserver
+      '@deepseek-ai/dsh-message-feedback':
+        specifier: workspace:^
+        version: link:../../feedback/message-feedback
       '@deepseek-ai/dsh-session-projection-cache':
         specifier: workspace:^
         version: link:../../session/session-projection-cache
@@ -3829,6 +3832,55 @@ importers:
         specifier: workspace:^
         version: link:../../session/user-id
 
+  packages/feedback/message-feedback:
+    dependencies:
+      '@deepseek-ai/schemastery':
+        specifier: link:../../../vendor/schemastery
+        version: link:../../../vendor/schemastery
+      zod:
+        specifier: ^4.4.3
+        version: 4.4.3
+    devDependencies:
+      '@deepseek-ai/cordis':
+        specifier: workspace:^
+        version: link:../../../vendor/cordis
+      '@deepseek-ai/cordis-plugin-include':
+        specifier: workspace:^
+        version: link:../../../vendor/include
+      '@deepseek-ai/cordis-plugin-loader':
+        specifier: workspace:^
+        version: link:../../../vendor/loader
+      '@deepseek-ai/dsh-brand':
+        specifier: workspace:^
+        version: link:../../util/brand
+      '@deepseek-ai/dsh-invariants':
+        specifier: workspace:^
+        version: link:../../support/invariants
+      '@deepseek-ai/dsh-llm':
+        specifier: workspace:^
+        version: link:../../llm/llm
+      '@deepseek-ai/dsh-session':
+        specifier: workspace:^
+        version: link:../../core/session
+      '@deepseek-ai/dsh-session-persistence':
+        specifier: workspace:^
+        version: link:../../session/session-persistence
+      '@deepseek-ai/dsh-session-persistence-jsonl':
+        specifier: workspace:^
+        version: link:../../session/session-persistence-jsonl
+      '@deepseek-ai/dsh-storage':
+        specifier: workspace:^
+        version: link:../../storage/storage
+      '@deepseek-ai/dsh-storage-domain':
+        specifier: workspace:^
+        version: link:../../storage/storage-domain
+      '@deepseek-ai/dsh-storage-json':
+        specifier: workspace:^
+        version: link:../../storage/storage-json
+      '@deepseek-ai/dsh-type-meta':
+        specifier: workspace:^
+        version: link:../../typert/type-meta
+
   packages/fs/fs:
     devDependencies:
       '@deepseek-ai/cordis':
diff --git a/scripts/gen-cordis-catalog.ts b/scripts/gen-cordis-catalog.ts
index b6a315d7ad..a32117bab8 100644
--- a/scripts/gen-cordis-catalog.ts
+++ b/scripts/gen-cordis-catalog.ts
@@ -63,6 +63,7 @@ export const SERVICE_PAGE: Record<string, string> = {
   httpServer: 'http-server.md',
   invariants: 'invariants.md',
   llm: 'llm-streaming.md',
+  messageFeedback: 'feedback.md',
   permission: 'permission.md',
   planMode: 'plan.md',
   pty: 'pty.md',
@@ -229,6 +230,25 @@ export const LINK_MAP: Readonly<Record<string, string>> = {
   ResolvedRetryPolicy: 'llm-streaming.md',
   Message: 'llm-streaming.md',
   MessageSource: 'llm-streaming.md',
+  MessageFeedbackDeleteRequest: 'feedback.md',
+  MessageFeedbackDeleteResult: 'feedback.md',
+  MessageFeedbackDeleteValue: 'feedback.md',
+  MessageFeedbackFailure: 'feedback.md',
+  MessageFeedbackItem: 'feedback.md',
+  MessageFeedbackListRequest: 'feedback.md',
+  MessageFeedbackListResult: 'feedback.md',
+  MessageFeedbackListValue: 'feedback.md',
+  MessageFeedbackNoteBlank: 'feedback.md',
+  MessageFeedbackNoteTooLarge: 'feedback.md',
+  MessageFeedbackPutRequest: 'feedback.md',
+  MessageFeedbackPutResult: 'feedback.md',
+  MessageFeedbackRating: 'feedback.md',
+  MessageFeedbackRejected: 'feedback.md',
+  MessageFeedbackSessionNotFound: 'feedback.md',
+  MessageFeedbackSuccess: 'feedback.md',
+  MessageFeedbackTargetNotFound: 'feedback.md',
+  MessageFeedbackVersion: 'feedback.md',
+  MessageFeedbackVersionConflict: 'feedback.md',
   UserMessage: 'session.md',
   PreStepDecision: 'core.md',
   PreStepContext: 'core.md',
diff --git a/scripts/gen-doc-graphs.ts b/scripts/gen-doc-graphs.ts
index 699bcae707..5b950782b1 100644
--- a/scripts/gen-doc-graphs.ts
+++ b/scripts/gen-doc-graphs.ts
@@ -135,7 +135,7 @@ const SERVICE_ROLES: ServiceRole[] = [
     pkg: 'session',
     title: 'In-memory session store',
     mode: 'core',
-    consumers: ['agent-loop', 'agent', 'session-persistence', 'session-query', 'session-query-sqlite', 'subagent-inprocess', 'invariants'],
+    consumers: ['agent-loop', 'agent', 'session-persistence', 'session-query', 'session-query-sqlite', 'subagent-inprocess', 'invariants', 'message-feedback'],
     note: 'Owns append-only Session instances and emits the durable session event feed.',
   },
   {
@@ -167,7 +167,7 @@ const SERVICE_ROLES: ServiceRole[] = [
     title: 'Durable session persistence seam',
     mode: 'seam',
     implementations: ['session-persistence-jsonl', 'session-persistence-sqlite'],
-    consumers: ['agent-loop', 'tool-bash', 'hooks-claude', 'hooks-codex', 'session-query', 'session-query-sqlite'],
+    consumers: ['agent-loop', 'tool-bash', 'hooks-claude', 'hooks-codex', 'session-query', 'session-query-sqlite', 'message-feedback'],
     note: 'Backends persist the same SessionEvent vocabulary; apps choose a backend at composition time.',
   },
   {
@@ -211,9 +211,16 @@ const SERVICE_ROLES: ServiceRole[] = [
     pkg: 'storage-domain',
     title: 'Domain data facility',
     mode: 'core',
-    consumers: ['workspace'],
+    consumers: ['workspace', 'message-feedback'],
     note: 'Waits for every configured backend, then publishes the domain form as one lifecycle-bound service for typed durable state.',
   },
+  {
+    key: 'messageFeedback',
+    pkg: 'message-feedback',
+    title: 'Lifecycle-bound message feedback',
+    mode: 'core',
+    note: 'Owns local per-assistant-message feedback, lifecycle and target validation, per-item compare-and-set, and the Host unary Remote contract without entering Session history or telemetry.',
+  },
   {
     key: 'workspace',
     pkg: 'workspace',
diff --git a/scripts/type-equiv.manifest.json b/scripts/type-equiv.manifest.json
index c1b1b2753a..3c6ef4e192 100644
--- a/scripts/type-equiv.manifest.json
+++ b/scripts/type-equiv.manifest.json
@@ -1739,6 +1739,101 @@
       "doc": "docs/subsystems/core.md",
       "symbol": "AgentOptions",
       "source": "packages/core/agent/src/runtime-types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackVersion",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackRating",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackItem",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackListRequest",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackListValue",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackPutRequest",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackDeleteRequest",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackDeleteValue",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackSessionNotFound",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackTargetNotFound",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackVersionConflict",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackNoteBlank",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackNoteTooLarge",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackFailure",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackSuccess",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackRejected",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackListResult",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackPutResult",
+      "source": "packages/feedback/message-feedback/src/types.ts"
+    },
+    {
+      "doc": "docs/subsystems/feedback.md",
+      "symbol": "MessageFeedbackDeleteResult",
+      "source": "packages/feedback/message-feedback/src/types.ts"
     }
   ]
 }
diff --git a/tsconfig.host.json b/tsconfig.host.json
index 690656e150..2beed0b1c3 100644
--- a/tsconfig.host.json
+++ b/tsconfig.host.json
@@ -14,6 +14,7 @@
     "apps/web/tests/support.ts",
     "apps/web/tests/scaffold-hermetic.e2e.ts",
     "apps/web/tests/minimal-preset.snapshot.ts",
+    "apps/web/tests/message-feedback-protocol.snapshot.ts",
     "apps/web/tests/live-interactions.e2e.ts",
     "apps/web/tests/question-composer.e2e.ts",
     "apps/web/tests/approval-composer.e2e.ts",
@@ -135,6 +136,7 @@
     { "path": "./packages/storage/storage-json" },
     { "path": "./packages/storage/storage-sqlite" },
     { "path": "./packages/storage/storage-domain" },
+    { "path": "./packages/feedback/message-feedback" },
     { "path": "./packages/workspace/workspace" },
     { "path": "./packages/session/session-title" },
     { "path": "./packages/session/session-title-llm" },