Merge pull request #1979 from deepseek-harness/worktree/derive-compaction-replay-1971

test(snapshot): derive compaction replay from persisted summaries

docs/config-catalog.md

@@ -857,7 +857,7 @@ export interface ReplayModelConfig {
 
 Depends on: [`RetryPolicyConfig`](../packages/llm/llm/src/index.ts)
 
-Source: [`packages/support/llm-replay/src/index.ts:710`](../packages/support/llm-replay/src/index.ts)
+Source: [`packages/support/llm-replay/src/index.ts:731`](../packages/support/llm-replay/src/index.ts)
 
 ## `@deepseek-ai/dsh-llm-retry`
 

docs/module-graph.md

@@ -422,9 +422,6 @@ flowchart TD
   pkg_session_persistence --> pkg_brand
   pkg_session_persistence --> pkg_invariants
   pkg_session_persistence --> pkg_session
-  pkg_llm_replay --> pkg_invariants
-  pkg_llm_replay --> pkg_llm
-  pkg_llm_replay --> pkg_session
   pkg_app_boot --> pkg_environment
   pkg_app_boot --> pkg_invariants
   pkg_app_boot --> pkg_paths
@@ -500,6 +497,10 @@ flowchart TD
   pkg_session_title --> pkg_llm
   pkg_session_title --> pkg_session
   pkg_session_title --> pkg_session_projection
+  pkg_llm_replay --> pkg_compact
+  pkg_llm_replay --> pkg_invariants
+  pkg_llm_replay --> pkg_llm
+  pkg_llm_replay --> pkg_session
   pkg_commands --> pkg_agent
   pkg_commands --> pkg_brand
   pkg_commands --> pkg_invariants
@@ -1219,7 +1220,6 @@ flowchart TD
 | [`web-search-perplexity`](../packages/web/web-search-perplexity) | `web` | [`environment`](../packages/util/environment), [`invariants`](../packages/support/invariants), [`web`](../packages/web/web) |
 | [`spill`](../packages/spill/spill) | `spill` | [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session) |
 | [`session-persistence`](../packages/session-persistence/session-persistence) | `session-persistence` | [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`session`](../packages/core/session) |
-| [`llm-replay`](../packages/support/llm-replay) | `support` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session) |
 | [`app-boot`](../packages/ui/app-boot) | `ui` | [`environment`](../packages/util/environment), [`invariants`](../packages/support/invariants), [`paths`](../packages/util/paths), [`system-prompt`](../packages/core/system-prompt) |
 | [`code-runtime-worker`](../packages/code-runtime/code-runtime-worker) | `code-runtime` | [`code-runtime`](../packages/code-runtime/code-runtime), [`invariants`](../packages/support/invariants), [`session`](../packages/core/session), [`timeout`](../packages/util/timeout) |
 | [`lsp-local`](../packages/lsp/lsp-local) | `lsp` | [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`lsp`](../packages/lsp/lsp), [`subprocess`](../packages/subprocess/subprocess), [`timeout`](../packages/util/timeout) |
@@ -1239,6 +1239,7 @@ flowchart TD
 | [`session-persistence-jsonl`](../packages/session-persistence/session-persistence-jsonl) | `session-persistence` | [`invariants`](../packages/support/invariants), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence) |
 | [`session-persistence-sqlite`](../packages/session-persistence/session-persistence-sqlite) | `session-persistence` | [`invariants`](../packages/support/invariants), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence) |
 | [`session-title`](../packages/session-title/session-title) | `session-title` | [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`session-projection`](../packages/session-projection/session-projection) |
+| [`llm-replay`](../packages/support/llm-replay) | `support` | [`compact`](../packages/compact/compact), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session) |
 | [`commands`](../packages/ui/commands) | `ui` | [`agent`](../packages/core/agent), [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`scope`](../packages/core/scope), [`session`](../packages/core/session) |
 | [`user-approval`](../packages/ui/user-approval) | `ui` | [`agent`](../packages/core/agent), [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`scope`](../packages/core/scope), [`session`](../packages/core/session), [`system-prompt`](../packages/core/system-prompt) |
 | [`user-interaction`](../packages/ui/user-interaction) | `ui` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm) |

examples/headless-agent/compaction.cordis.snapshot.yml

@@ -0,0 +1,25 @@
+# Keyless context-overflow composition for the assembled compaction snapshot.
+- id: base
+  name: '@cordisjs/plugin-include'
+  config:
+    path: ./cordis.yml
+    patches:
+      - id: llm-deepseek
+        name: '@deepseek-ai/dsh-llm-deepseek'
+        disabled: true
+      - id: compact-basic
+        name: '@deepseek-ai/dsh-compact-basic'
+        config:
+          thresholdRatio: 0.99
+          retainTokens: 20
+          maxTokens: 32
+          compactionRetries: 1
+      - insert:
+          - id: llm-replay
+            name: '@deepseek-ai/dsh-llm-replay'
+            config:
+              providers:
+                - id: deepseek-official
+                  models:
+                    - id: deepseek-v4-flash
+                      contextWindow: 128000

examples/headless-agent/tests/compaction.e2e.ts

@@ -11,8 +11,8 @@ import { SessionId } from '@deepseek-ai/dsh-session'
  * Key-gated smoke for mid-session compaction. It verifies the compact event
  * pair, replacement of older surface nodes, and a final answer after compaction.
  */
-// FIXME(compaction-snapshot): this is the only full compaction coverage because
-// replay cannot serve the summarizer's unlogged model call.
+// The keyless headless snapshot pins deterministic overflow recovery; this test
+// remains the independent live-provider smoke for organic pressure and summary quality.
 
 let workdir: string | undefined
 let ctx: Context | undefined

examples/headless-agent/tests/headless.snapshot.ts

@@ -29,6 +29,10 @@ const goalScenarioDir = join(snapshotsDir, 'goal-tools')
 const goalConfigPath = fileURLToPath(new URL('../goal.cordis.snapshot.yml', import.meta.url))
 const retryScenarioDir = join(snapshotsDir, 'provider-retry')
 const retryConfigPath = fileURLToPath(new URL('../retry.cordis.snapshot.yml', import.meta.url))
+const compactionScenarioDir = join(snapshotsDir, 'compaction-recovery')
+const compactionSessionFixture = join(compactionScenarioDir, 'session.jsonl')
+const compactionStreamExpected = join(compactionScenarioDir, 'stream-json.expected.jsonl')
+const compactionConfigPath = fileURLToPath(new URL('../compaction.cordis.snapshot.yml', import.meta.url))
 const credentialsScenarioDir = join(snapshotsDir, 'missing-credential')
 const credentialsConfigPath = fileURLToPath(new URL('../credentials.cordis.snapshot.yml', import.meta.url))
 // Same keyless composition as the missing-credential scenario: the endpoint is
@@ -227,6 +231,75 @@ describe('headless stream-json snapshots', () => {
     expect(normalized).toBe(await readFile(streamExpected, 'utf8'))
   }, LOADER_SMOKE_TEST_TIMEOUT_MS)
 
+  it('recovers from context overflow through an assembled compaction', async () => {
+    const prompt = await scenarioPrompt(compactionScenarioDir, 'compaction-recovery')
+    let expectedSession = await readFile(compactionSessionFixture, 'utf8')
+    let runCwd = ''
+    const result = await runLoaderSmoke({
+      label: 'compaction recovery headless stream-json snapshot',
+      tempDirPrefix: 'headless-snapshot-compaction-recovery-',
+      binScript,
+      configPath: compactionConfigPath,
+      binArgs: ['--config', compactionConfigPath, '--output-format', 'stream-json', prompt],
+      tsconfigPath,
+      env: {
+        DSH_SNAPSHOT: 'replay',
+        DSH_SNAPSHOT_FILE: compactionSessionFixture,
+        NODE_OPTIONS: [process.env.NODE_OPTIONS, '--disable-warning=ExperimentalWarning'].filter(Boolean).join(' '),
+      },
+      prepare: (cwd) => { runCwd = cwd },
+      inspect: async (cwd) => {
+        const logs = await persistedLogs(cwd)
+        expect(logs).toHaveLength(1)
+        const actual = logs[0]
+        if (actual === undefined) throw new Error('compaction snapshot did not persist its session')
+        const records = parseJsonl(actual.content)
+        const types = records.map(record => record.type)
+        expect(types.filter(type => type === 'compact/start')).toHaveLength(1)
+        expect(types.filter(type => type === 'compact/summary')).toHaveLength(1)
+        expect(types.filter(type => type === 'compact/end')).toHaveLength(1)
+        const start = types.indexOf('compact/start')
+        const summary = types.indexOf('compact/summary')
+        const replacement = records.findIndex((record) => {
+          if (record.type !== 'user/message') return false
+          const surfaceOp = record.surfaceOp as JsonObject | undefined
+          return surfaceOp?.op === 'replace'
+        })
+        const end = types.indexOf('compact/end')
+        expect(start).toBeLessThan(summary)
+        expect(summary).toBeLessThan(replacement)
+        expect(replacement).toBeLessThan(end)
+        const summaryRecord = records[summary]
+        const summaryData = summaryRecord?.data as JsonObject | undefined
+        expect(summaryData?.shadowedSeqs).toEqual(expect.arrayContaining([expect.any(Number)]))
+        const final = [...records].reverse().find(record => record.type === 'assistant/message')
+        expect(JSON.stringify(final)).toContain('COMPACTION RECOVERED')
+
+        const actualContext = contextFromLogs([actual.content])
+        if (refreshing) {
+          const harvested: HarvestedLog = {
+            id: String(actual.header.id),
+            createdAt: Number(actual.header.createdAt),
+            content: actual.content,
+          }
+          const replacements = refreshFixtureReplacements([harvested], [expectedSession])
+          expectedSession = tokenizeSessionFixtureCwd(
+            stabilizeRefreshLog(actual.content, expectedSession, replacements, actualContext),
+          )
+          await writeFile(compactionSessionFixture, expectedSession)
+        }
+        const expectedContext = contextFromLogs([expectedSession])
+        expect(scrubRequestHeaders(normalizeSessionLog(actual.content, actualContext)))
+          .toBe(scrubRequestHeaders(normalizeSessionLog(expectedSession, expectedContext)))
+      },
+    })
+
+    expect(result.stderr).toBe('')
+    const normalized = normalizeHeadlessStream(result.stdout, runCwd)
+    if (refreshing) await writeFile(compactionStreamExpected, normalized)
+    expect(normalized).toBe(await readFile(compactionStreamExpected, 'utf8'))
+  }, LOADER_SMOKE_TEST_TIMEOUT_MS)
+
   it('logs actionable missing-credential guidance through the one-shot app', async () => {
     const streamExpected = join(credentialsScenarioDir, 'stream-json.expected.jsonl')
     let runCwd = ''

examples/headless-agent/tests/snapshots/compaction-recovery/input.json

@@ -0,0 +1,8 @@
+{
+  "steps": [
+    {
+      "op": "prompt",
+      "text": "Establish a durable compaction premise before continuing. Record every part of this historical evidence: the snapshot uses keyless replay; persistence uses JSONL; the assembled headless application loads its real Cordis composition; model-visible inputs remain logged; tool calls and results remain paired and ordered; context overflow retains the original failure while recovery is attempted; compaction opens with compact/start and closes with compact/end; a successful auxiliary summary records compact/summary provenance; the replacement surface shadows only an older balanced range; the checkpoint remains smaller than the history it replaces; the newest tool result remains verbatim; the retried request sees that checkpoint; the final response proves the same turn continued; deterministic snapshot evidence stays separate from the live-provider smoke; and no external API key is needed. Emit one alpha marker through bash, then finish the task after any required recovery with the exact words COMPACTION RECOVERED."
+    }
+  ]
+}

examples/headless-agent/tests/snapshots/compaction-recovery/stream-json.expected.jsonl

@@ -0,0 +1,32 @@
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"agent/inbox/spliced","seq":0,"time":0,"data":{"target":"next-turn","start":0,"inserted":[{"content":[{"type":"text","text":"Establish a durable compaction premise before continuing. Record every part of this historical evidence: the snapshot uses keyless replay; persistence uses JSONL; the assembled headless application loads its real Cordis composition; model-visible inputs remain logged; tool calls and results remain paired and ordered; context overflow retains the original failure while recovery is attempted; compaction opens with compact/start and closes with compact/end; a successful auxiliary summary records compact/summary provenance; the replacement surface shadows only an older balanced range; the checkpoint remains smaller than the history it replaces; the newest tool result remains verbatim; the retried request sees that checkpoint; the final response proves the same turn continued; deterministic snapshot evidence stays separate from the live-provider smoke; and no external API key is needed. Emit one alpha marker through bash, then finish the task after any required recovery with the exact words COMPACTION RECOVERED."}],"source":{"kind":"user"},"role":"user","id":"{{sessionId}}"}]}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"turn/start","seq":1,"time":0,"data":{"turn":1}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"agent/inbox/spliced","seq":2,"time":0,"data":{"target":"next-turn","start":0,"removedCount":1,"inserted":[]}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"step/start","seq":3,"time":0,"data":{"turn":1,"step":1}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"user/message","seq":4,"time":0,"data":{"content":[{"type":"text","text":"Establish a durable compaction premise before continuing. Record every part of this historical evidence: the snapshot uses keyless replay; persistence uses JSONL; the assembled headless application loads its real Cordis composition; model-visible inputs remain logged; tool calls and results remain paired and ordered; context overflow retains the original failure while recovery is attempted; compaction opens with compact/start and closes with compact/end; a successful auxiliary summary records compact/summary provenance; the replacement surface shadows only an older balanced range; the checkpoint remains smaller than the history it replaces; the newest tool result remains verbatim; the retried request sees that checkpoint; the final response proves the same turn continued; deterministic snapshot evidence stays separate from the live-provider smoke; and no external API key is needed. Emit one alpha marker through bash, then finish the task after any required recovery with the exact words COMPACTION RECOVERED."}],"source":{"kind":"user"},"role":"user","id":"{{sessionId}}"},"surfaceOp":"append"}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"session/title","seq":5,"time":0,"data":{"title":"Establish a durable compaction premise","messageSeqs":[4],"source":{"kind":"fallback"}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"request/header","seq":6,"time":0,"data":{"header":{"config":{"provider":"deepseek-official","model":"deepseek-v4-flash"},"system":"{{system}}","tools":"{{tools}}"},"reason":"initial"}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"request/context","seq":7,"time":0,"data":{"provider":"deepseek-official","model":"deepseek-v4-flash","contextWindow":128000}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":8,"time":0,"data":{"turn":1,"step":1,"chunk":{"type":"block-start","index":0,"blockType":"tool-call"}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":9,"time":0,"data":{"turn":1,"step":1,"chunk":{"type":"tool-call-delta","index":0,"id":"call_compaction_marker","name":"bash","argumentsDelta":"{\"command\":\"printf 'alpha\\n'\",\"description\":\"Emit compaction premise marker\"}"}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":10,"time":0,"data":{"turn":1,"step":1,"chunk":{"type":"block-end","index":0,"block":{"type":"tool-call","id":"call_compaction_marker","name":"bash","arguments":"{\"command\":\"printf 'alpha\\n'\",\"description\":\"Emit compaction premise marker\"}"}}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":11,"time":0,"data":{"turn":1,"step":1,"chunk":{"type":"usage","usage":{"inputTokens":24,"outputTokens":6}}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":12,"time":0,"data":{"turn":1,"step":1,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/message","seq":13,"time":0,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"tool-call","id":"call_compaction_marker","name":"bash","arguments":"{\"command\":\"printf 'alpha\\n'\",\"description\":\"Emit compaction premise marker\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"{{sessionId}}"},"usage":{"inputTokens":24,"outputTokens":6}},"sourceEventSeqs":[8,9,10,11,12],"surfaceOp":"append"}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"tool/call","seq":14,"time":0,"data":{"turn":1,"step":1,"callId":"call_compaction_marker","name":"bash","arguments":"{\"command\":\"printf 'alpha\\n'\",\"description\":\"Emit compaction premise marker\"}"}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"tool/result","seq":15,"time":0,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_compaction_marker"},"content":[{"type":"tool-result","toolCallId":"call_compaction_marker","content":[{"type":"text","text":"alpha\n"}],"isError":false}],"role":"user","id":"{{sessionId}}"}},"sourceEventSeqs":[14],"surfaceOp":"append"}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"step/end","seq":16,"time":0,"data":{"turn":1,"step":1}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"step/start","seq":17,"time":0,"data":{"turn":1,"step":2}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":18,"time":0,"data":{"turn":1,"step":2,"chunk":{"type":"finish","reason":{"kind":"error","failure":{"message":"snapshot request exceeded the model context window","code":"CONTEXT_WINDOW_EXCEEDED"}}}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"compact/start","seq":19,"time":0,"data":{"turn":1}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"compact/summary","seq":20,"time":0,"data":{"summary":[{"type":"text","text":"The request established a durable compaction premise."}],"rawOutput":[{"type":"text","text":"The request established a durable compaction premise."}],"shadowedRange":{"start":4,"end":4},"shadowedSeqs":[4],"shadowedTokenCount":264,"provider":"deepseek-official","model":"deepseek-v4-flash","maxTokens":32,"usage":{"inputTokens":20,"outputTokens":4}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"user/message","seq":21,"time":0,"data":{"content":[{"type":"text","text":"This is an automatically generated checkpoint condensing an earlier span of the conversation to free up context. Treat the captured context as established background and build on it without restating it. Continue the task directly from the messages that follow, without acknowledging this checkpoint.\n\n<compacted-summary>"},{"type":"text","text":"The request established a durable compaction premise."},{"type":"text","text":"</compacted-summary>"}],"source":{"kind":"plugin","plugin":"compact"},"role":"user","id":"{{sessionId}}"},"sourceEventSeqs":[19,20,4],"surfaceOp":{"op":"replace","start":4,"end":4}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"compact/end","seq":22,"time":0,"data":{"turn":1}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":23,"time":0,"data":{"turn":1,"step":2,"chunk":{"type":"block-start","index":0,"blockType":"text"}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":24,"time":0,"data":{"turn":1,"step":2,"chunk":{"type":"text-delta","index":0,"text":"COMPACTION RECOVERED"}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":25,"time":0,"data":{"turn":1,"step":2,"chunk":{"type":"block-end","index":0,"block":{"type":"text","text":"COMPACTION RECOVERED"}}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":26,"time":0,"data":{"turn":1,"step":2,"chunk":{"type":"usage","usage":{"inputTokens":20,"outputTokens":4}}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/chunk","seq":27,"time":0,"data":{"turn":1,"step":2,"chunk":{"type":"finish","reason":{"kind":"stop"}}}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"assistant/message","seq":28,"time":0,"data":{"turn":1,"step":2,"message":{"role":"assistant","content":[{"type":"text","text":"COMPACTION RECOVERED"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"{{sessionId}}"},"usage":{"inputTokens":20,"outputTokens":4}},"sourceEventSeqs":[23,24,25,26,27],"surfaceOp":"append"}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"step/end","seq":29,"time":0,"data":{"turn":1,"step":2}}}
+{"type":"session_event","sessionId":"{{sessionId}}","event":{"type":"turn/end","seq":30,"time":0,"data":{"turn":1,"reason":{"kind":"completed"}}}}
+{"type":"result","sessionId":"{{sessionId}}","output":"COMPACTION RECOVERED","usage":{"inputTokens":44,"outputTokens":10}}

packages/support/llm-replay/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/support/llm-replay/README.md
-README.md: ee062d0c2804905f33f1ff476d12bb6dd57666e5
-README.zh.md: ab3420d9500a6ca77f04a2ad96095f8883aeb874
+README.md: 46d391970f320708914d11f0868cbbc5361ae196
+README.zh.md: a67b078a1396968dc3ddecb0e616a832c4faaf3a

packages/support/llm-replay/README.md

@@ -8,7 +8,9 @@ Its consumers are the ACP and headless `stream-json` snapshot suites plus the We
 
 ## How the fixture works
 
-The fixture IS the persisted session log (`<scenario>/session.jsonl`). Its `assistant/chunk` events carry every `StreamChunk`, so grouping them by `(turn, step)` reconstructs each `stream()` call's chunk sequence (one model call per loop step). Recording is therefore "run the real agent once and harvest the `.jsonl`", done by the snapshot harness — this plugin does not record. A fixture may carry its `request/header` content tokenized to `{{system}}`/`{{tools}}` (the harness pins that content in one scenario and scrubs the rest); replay is indifferent — derivation reads only `assistant/chunk` events and the line-0 session header.
+The fixture IS the persisted session log (`<scenario>/session.jsonl`). Its `assistant/chunk` events carry every `StreamChunk`, so grouping them by `(turn, step)` reconstructs each agent-loop `stream()` call's chunk sequence. A successful compaction summarizer is logged differently: when `compact/summary` carries its complete `rawOutput`, replay reconstructs a canonical successful stream at that event's position using one `block-start`/`block-end` pair per block, the recorded usage when present, and a terminal `stop`. Exact provider delta partitioning is not part of the durable compaction result. A summary without `rawOutput` does not imply an LLM call because template and remote summarizers may produce it without the local adapter.
+
+Recording is therefore "run the real agent once and harvest the `.jsonl`", done by the snapshot harness — this plugin does not record. A fixture may carry its `request/header` content tokenized to `{{system}}`/`{{tools}}` (the harness pins that content in one scenario and scrubs the rest); replay is indifferent — derivation reads only `assistant/chunk` and `compact/summary` events plus the line-0 session header.
 
 Two failure modes are not reconstructable from `assistant/chunk` alone — a pure throw before any chunk (e.g. an HTTP 401, where the log holds only a `turn/end {error}` and no chunks) and a cancel/hang (timing, not chunk content). A scenario that needs those supplies an optional sidecar (`<scenario>/replay.override.json`) that either replaces the derived script (a bare `ReplayEntry[]`) or augments it (`{ patches: [{ at, entry }] }`: keep every JSONL-derived call and swap the named 0-based call indexes; `at` equal to the derived length appends the retry attempt after an injected transient throw). Patch indexes must be unique. The override document, each patch and entry, and every chunk discriminant are validated when the file loads. A `hang` entry may name `readyFile`; replay writes that empty marker after its prefix chunks reach the loop and before it waits for cancellation, so an external driver can cancel deterministically without observing a presentation update.
 
@@ -57,7 +59,7 @@ Replay keys every call by its calling session id (`GenerateOptions.sessionId`, s
 - `installLlmReplay(ctx, config)` — install the configured replay adapter or catch-all `llm/stream` listener; returns a `ReplayHandle` (`dispose()` for HMR safety plus `assertConsumed()`, the teardown check that every recorded script bound to a live session and every bound cursor drained — turning a scenario that silently drove fewer model calls than recorded into a crisp diagnostic). Use this in tests to drive replay without the Loader or env vars.
 - `loadSessionScripts(config)` — resolve the ordered `SessionScript[]` (primary + children) for a scenario, ready to bind to live sessions in first-call order.
 - `loadReplayScript(config)` — resolve the `ReplayEntry[]` for the primary session only (validated sidecar replacement/patches if present, else derived from the JSONL; fail-loud if the fixture is missing).
-- `deriveReplayScript(events)` / `parseSessionLog(text)` / `parseSessionHeader(text)` / `resolveScriptedEntry(entry, messages)` — the pure helpers that turn a recorded session log into a script, read its header `id`/`createdAt`, and resolve `{{fromRequest:...}}` placeholders against one live request. A derived group must end in a `finish` chunk; a group without one is the fingerprint of a thrown `stream()` and must instead be expressed via an override sidecar.
+- `deriveReplayScript(events)` / `parseSessionLog(text)` / `parseSessionHeader(text)` / `resolveScriptedEntry(entry, messages)` — the pure helpers that turn ordinary loop chunks and complete compaction outputs in a recorded session log into a script, read its header `id`/`createdAt`, and resolve `{{fromRequest:...}}` placeholders against one live request. A derived assistant group must end in a `finish` chunk; a group without one is the fingerprint of a thrown `stream()` and must instead be expressed via an override sidecar.
 - Types `ReplayEntry` / `ReplayOverrideDoc` / `ReplayOverridePatch` / `SessionScript` / `ReplayConfig` / `ReplayProviderConfig` / `ReplayModelConfig` / `ReplayHandle` / `Config`.
 
 ## Plugin export shape
@@ -74,5 +76,5 @@ None; this package neither assembles nor sends a provider request.
 
 ## Known Limitations and Deferred Work
 
-- **First-call-order script binding assumes sequential delegation** — a cut that runs sibling subagents concurrently (or a compaction summarize call landing mid-run) would bind live sessions to recorded scripts non-deterministically; a stronger keying is deferred until such a scenario exists (`XXX(concurrent-subagents)`).
-- **Only chunk-producing calls are derivable** — a pure pre-chunk throw or a cancel/hang scenario needs the `replay.override.json` sidecar. Replacement and patch forms affect only the primary session; child scripts still derive from their logs.
+- **First-call-order script binding assumes sequential delegation** — a cut that runs sibling subagents concurrently would bind live sessions to recorded scripts non-deterministically; a stronger keying is deferred until such a scenario exists (`XXX(concurrent-subagents)`).
+- **Only ordinary loop chunks and completed compaction outputs are derivable** — a pure pre-chunk throw or a cancel/hang scenario needs the `replay.override.json` sidecar. Replacement and patch forms affect only the primary session; child scripts still derive from their logs.

packages/support/llm-replay/README.zh.md

@@ -8,7 +8,9 @@
 
 ## fixture 的工作方式
 
-fixture 就是持久化的会话日志（`<scenario>/session.jsonl`）。其 `assistant/chunk` 事件包含每个 `StreamChunk`，因此按 `(turn, step)` 分组即可重建每次 `stream()` 调用的分片序列（每个循环步骤调用一次模型）。因此，录制就是「运行一次真实 agent 并收集 `.jsonl`」，由快照 harness 完成；该插件本身不录制。fixture 的 `request/header` 内容可能被标记化为 `{{system}}`/`{{tools}}`（harness 会在一个场景中固定该内容，并清除其余场景中的内容）；回放不受影响，因为派生过程只读取 `assistant/chunk` 事件和第 0 行的会话 header。
+fixture 就是持久化的会话日志（`<scenario>/session.jsonl`）。其 `assistant/chunk` 事件包含每个 `StreamChunk`，因此按 `(turn, step)` 分组即可重建每次 agent-loop `stream()` 调用的分片序列。压缩（compaction）摘要器成功时，日志记录方式有所不同：当 `compact/summary` 携带完整的 `rawOutput` 时，回放会在该事件的位置重建一条规范成功流，其中每个块各使用一对 `block-start`/`block-end`，带上已记录的 usage（如有），并以 `stop` 终止。提供方增量的精确切分不属于持久压缩结果。不带 `rawOutput` 的摘要并不意味着发生了 LLM 调用，因为模板摘要器和远程摘要器可能不经本地适配器生成该摘要。
+
+因此，录制就是「运行一次真实 agent 并收集 `.jsonl`」，由快照 harness 完成；该插件本身不录制。fixture 的 `request/header` 内容可能被标记化为 `{{system}}`/`{{tools}}`（harness 会在一个场景中固定该内容，并清除其余场景中的内容）；回放不受影响，因为派生过程只读取 `assistant/chunk` 和 `compact/summary` 事件以及第 0 行的会话 header。
 
 有两种失败模式无法仅根据 `assistant/chunk` 重建：在产生任何分片前直接抛出异常（例如 HTTP 401，此时日志只有 `turn/end {error}` 而没有分片），以及取消或挂起（差异在时序，而非分片内容）。需要这些行为的场景可提供伴随文件（`<scenario>/replay.override.json`）：它可以替换派生脚本（裸 `ReplayEntry[]`），也可以增补派生脚本（`{ patches: [{ at, entry }] }`：保留所有从 JSONL 派生的调用，只替换指定的从 0 开始计数的调用索引；当 `at` 等于派生长度时，则在注入瞬态异常后的重试位置追加一次调用）。补丁索引不得重复。文件加载时会校验覆写文档、每个补丁和条目，以及每个分片的判别标签。`hang` 条目可以指定 `readyFile`；当前缀分片到达循环后、开始等待取消前，回放会写入这个空标记，使外部驱动程序无需观察展示层更新即可确定性地取消。
 
@@ -57,7 +59,7 @@ fixture 就是持久化的会话日志（`<scenario>/session.jsonl`）。其 `as
 - `installLlmReplay(ctx, config)`：安装已配置回放适配器或 catch-all `llm/stream` 监听器；返回 `ReplayHandle`（包含用于保证 HMR（热模块替换）安全的 `dispose()`，以及清理阶段执行的 `assertConsumed()` 检查；后者确保每个已记录脚本都绑定到实时会话，且每个已绑定游标都已耗尽，从而将场景静默驱动的模型调用少于记录数转换为明确诊断）。在测试中使用它，可以不通过 Loader 或 env var 驱动回放。
 - `loadSessionScripts(config)`：解析场景中有序的 `SessionScript[]`（主会话 + 子会话），准备按首次调用顺序绑定到实时会话。
 - `loadReplayScript(config)`：只解析主会话的 `ReplayEntry[]`（如果伴随文件存在，则使用经校验的替换或补丁；否则从 JSONL 派生；fixture 缺失时明确报错）。
-- `deriveReplayScript(events)` / `parseSessionLog(text)` / `parseSessionHeader(text)` / `resolveScriptedEntry(entry, messages)`：将已记录会话日志转换为脚本、读取其 header `id`/`createdAt`、并针对单次实时请求解析 `{{fromRequest:...}}` 占位符的纯辅助工具。派生分组必须以 `finish` 分片结束；没有该分片的分组是 `stream()` 抛出异常的指纹，必须改用 override 伴随文件表达。
+- `deriveReplayScript(events)` / `parseSessionLog(text)` / `parseSessionHeader(text)` / `resolveScriptedEntry(entry, messages)`：将已记录会话日志中的普通 loop 分片和完整压缩输出转换为脚本、读取其 header `id`/`createdAt`、并针对单次实时请求解析 `{{fromRequest:...}}` 占位符的纯辅助工具。派生的 assistant 分组必须以 `finish` 分片结束；没有该分片的分组是 `stream()` 抛出异常的指纹，必须改用 override 伴随文件表达。
 - 类型 `ReplayEntry` / `ReplayOverrideDoc` / `ReplayOverridePatch` / `SessionScript` / `ReplayConfig` / `ReplayProviderConfig` / `ReplayModelConfig` / `ReplayHandle` / `Config`。
 
 ## 插件导出形态
@@ -74,5 +76,5 @@ fixture 就是持久化的会话日志（`<scenario>/session.jsonl`）。其 `as
 
 ## 已知限制与暂缓事项
 
-- **首次调用顺序脚本绑定假设串行委托**：并发运行同级 subagent 的 cut（或运行中发生的上下文压缩（context compaction）摘要调用）会非确定性地将实时会话绑定到已记录脚本；在这种场景出现前暂不实现更强的键控（`XXX(concurrent-subagents)`）。
-- **只有会产生分片的调用才能派生**：在产生分片前直接抛出异常或取消/挂起的场景需要 `replay.override.json` 伴随文件。替换和补丁两种形式都只影响主会话；子会话脚本仍从各自日志派生。
+- **首次调用顺序脚本绑定假设串行委托**：并发运行同级 subagent 的 cut 会非确定性地将实时会话绑定到已记录脚本；在这种场景出现前暂不实现更强的键控（`XXX(concurrent-subagents)`）。
+- **只有普通 loop 分片和已完成的压缩输出才能派生**：在产生分片前直接抛出异常或取消/挂起的场景需要 `replay.override.json` 伴随文件。替换和补丁两种形式都只影响主会话；子会话脚本仍从各自日志派生。

packages/support/llm-replay/package.json

@@ -25,12 +25,14 @@
   ],
   "license": "BSD-3-Clause",
   "peerDependencies": {
+    "@deepseek-ai/dsh-compact": "^0.0.1",
     "@deepseek-ai/dsh-invariants": "^0.0.1",
     "@deepseek-ai/dsh-llm": "^0.0.1",
     "@deepseek-ai/dsh-session": "^0.0.1",
     "cordis": "^4.0.0-rc.7"
   },
   "devDependencies": {
+    "@deepseek-ai/dsh-compact": "workspace:^",
     "@deepseek-ai/dsh-invariants": "workspace:^",
     "@deepseek-ai/dsh-llm": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",

packages/support/llm-replay/src/index.ts

@@ -1,14 +1,16 @@
 /**
  * Keyless snapshot-test LLM replay. It derives one model-call script per
- * recorded session from `assistant/chunk` events and binds fresh live sessions
- * to parent/child scripts by first-call order. Throw and hang cases require an
- * explicit override because a session log cannot reconstruct them alone.
+ * recorded session from `assistant/chunk` events and durable compaction
+ * summaries, then binds fresh live sessions to parent/child scripts by
+ * first-call order. Throw and hang cases require an explicit override because
+ * a session log cannot reconstruct them alone.
  * @module @deepseek-ai/dsh-llm-replay
  */
 
 import { existsSync, readFileSync, writeFileSync } from 'node:fs'
 import { delimiter as pathDelimiter } from 'node:path'
 import type { Context } from 'cordis'
+import type {} from '@deepseek-ai/dsh-compact'
 import { decodeStorageRecord } from '@deepseek-ai/dsh-session'
 import type { SessionEvent } from '@deepseek-ai/dsh-session'
 import type {
@@ -24,8 +26,9 @@ import { LlmAdapter, LlmError, assertNever, resolveRetryPolicy } from '@deepseek
 
 /**
  * One recorded model call. `throw` may replay prefix chunks before failing;
- * `hang` models cancellation. Only ordinary chunk entries derive from JSONL;
- * the other variants come from an override sidecar.
+ * `hang` models cancellation. Chunk entries derive from ordinary model streams
+ * and complete compaction outputs in JSONL; the other variants come from an
+ * override sidecar.
  */
 export type ReplayEntry =
   | { kind: 'chunks'; chunks: StreamChunk[] }
@@ -174,10 +177,12 @@ export function parseSessionHeader(text: string): { id: string; createdAt: numbe
  * Reconstruct the per-`stream()` replay script from a recorded session log.
  *
  * Splits `assistant/chunk` events at every `finish`, using turn and step changes
- * to detect an unterminated prior call. A missing terminator means the live
- * stream threw, so derivation rejects and the scenario must provide an explicit
- * override. Multiple calls may share one turn and step when the loop retries.
- * @param events - the recorded session's events; only `assistant/chunk` is consulted.
+ * to detect an unterminated prior call. A complete `compact/summary.rawOutput`
+ * becomes a canonical successful stream at the summary's log position. A
+ * missing assistant terminator means the live stream threw, so derivation
+ * rejects and the scenario must provide an explicit override. Multiple calls
+ * may share one turn and step when the loop retries.
+ * @param events - the recorded session's events.
  * @returns one `chunks` entry per recorded model call, in call order.
  */
 export function deriveReplayScript(events: SessionEvent[]): ReplayEntry[] {
@@ -195,6 +200,22 @@ export function deriveReplayScript(events: SessionEvent[]): ReplayEntry[] {
     script.push({ kind: 'chunks', chunks })
   }
   for (const event of events) {
+    if (event.type === 'compact/summary') {
+      close(currentKey, current)
+      currentKey = undefined
+      current = []
+      if (event.data.rawOutput !== undefined) {
+        const chunks: StreamChunk[] = []
+        for (const [index, block] of event.data.rawOutput.entries()) {
+          chunks.push({ type: 'block-start', index, blockType: block.type })
+          chunks.push({ type: 'block-end', index, block })
+        }
+        if (event.data.usage !== undefined) chunks.push({ type: 'usage', usage: event.data.usage })
+        chunks.push({ type: 'finish', reason: { kind: 'stop' } })
+        script.push({ kind: 'chunks', chunks })
+      }
+      continue
+    }
     if (event.type !== 'assistant/chunk') continue
     const { turn, step, chunk } = event.data
     const key = `${turn}/${step}`

packages/support/llm-replay/tests/llm-replay.spec.ts

@@ -178,6 +178,93 @@ describe('deriveReplayScript', () => {
     expect(deriveReplayScript(events)).toEqual([{ kind: 'chunks', chunks: errChunks }])
   })
 
+  it('inserts compact/summary output between the calls surrounding it', () => {
+    const overflow: StreamChunk[] = [
+      { type: 'finish', reason: { kind: 'error', failure: { message: 'too large', code: 'CONTEXT_WINDOW_EXCEEDED' } } },
+    ]
+    const block = { type: 'text' as const, text: 'durable checkpoint' }
+    const rawOutput = [block]
+    const usage = { inputTokens: 9, outputTokens: 2 }
+    const summaryChunks: StreamChunk[] = [
+      { type: 'block-start', index: 0, blockType: 'text' },
+      { type: 'block-end', index: 0, block },
+      { type: 'usage', usage },
+      { type: 'finish', reason: { kind: 'stop' } },
+    ]
+    let seq = 1
+    const events: SessionEvent[] = [
+      ...overflow.map(chunk => chunkEvent(seq++, 1, 2, chunk)),
+      { type: 'compact/start', seq: seq++, time: 0, data: { turn: 1 } },
+      {
+        type: 'compact/summary',
+        seq: seq++,
+        time: 0,
+        data: {
+          summary: rawOutput,
+          rawOutput,
+          shadowedRange: { start: 1, end: 1 },
+          shadowedSeqs: [1],
+          shadowedTokenCount: 20,
+          provider: 'mock',
+          model: 'mock',
+          usage,
+        },
+      },
+      ...TEXT_CHUNKS.map(chunk => chunkEvent(seq++, 1, 2, chunk)),
+    ]
+
+    expect(deriveReplayScript(events)).toEqual([
+      { kind: 'chunks', chunks: overflow },
+      { kind: 'chunks', chunks: summaryChunks },
+      { kind: 'chunks', chunks: TEXT_CHUNKS },
+    ])
+  })
+
+  it('does not infer an LLM call from compact/summary without raw output', () => {
+    const event: SessionEvent<'compact/summary'> = {
+      type: 'compact/summary',
+      seq: 1,
+      time: 0,
+      data: {
+        summary: [{ type: 'text', text: 'template result' }],
+        shadowedRange: { start: 1, end: 1 },
+        shadowedSeqs: [1],
+        shadowedTokenCount: 20,
+        provider: 'template',
+        model: 'template',
+      },
+    }
+
+    expect(deriveReplayScript([event])).toEqual([])
+  })
+
+  it('derives a compact/summary stream when usage is unavailable', () => {
+    const block = { type: 'text' as const, text: 'summary without usage' }
+    const event: SessionEvent<'compact/summary'> = {
+      type: 'compact/summary',
+      seq: 1,
+      time: 0,
+      data: {
+        summary: [block],
+        rawOutput: [block],
+        shadowedRange: { start: 1, end: 1 },
+        shadowedSeqs: [1],
+        shadowedTokenCount: 20,
+        provider: 'mock',
+        model: 'mock',
+      },
+    }
+
+    expect(deriveReplayScript([event])).toEqual([{
+      kind: 'chunks',
+      chunks: [
+        { type: 'block-start', index: 0, blockType: 'text' },
+        { type: 'block-end', index: 0, block },
+        { type: 'finish', reason: { kind: 'stop' } },
+      ],
+    }])
+  })
+
   it('throws on a group that lacks a terminal finish chunk (a thrown stream)', () => {
     // A thrown stream(): prefix chunks logged, then turn/end (error reason), NO finish.
     const events: SessionEvent[] = [

packages/support/llm-replay/tsconfig.json

@@ -14,6 +14,9 @@
     {
       "path": "../../../vendor/cordis"
     },
+    {
+      "path": "../../compact/compact"
+    },
     {
       "path": "../../llm/llm"
     },

pnpm-lock.yaml

@@ -5959,6 +5959,9 @@ importers:
 
   packages/support/llm-replay:
     devDependencies:
+      '@deepseek-ai/dsh-compact':
+        specifier: workspace:^
+        version: link:../../compact/compact
       '@deepseek-ai/dsh-invariants':
         specifier: workspace:^
         version: link:../invariants