Merge pull request #1079 from deepseek-harness/feat/code-runtime-multilang-seam

feat(code-runtime): own portable-identifier exclusions at the seam

.agents/notes/implemented/architecture/2026-07-31-code-runtime-portable-identifier-seam.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/2026-07-31-code-runtime-portable-identifier-seam.md
+2026-07-31-code-runtime-portable-identifier-seam.md: 9e9df50235b3505458e3645e2c6ff6e9bd439183
+2026-07-31-code-runtime-portable-identifier-seam.zh.md: 31d2410ee4809d0693f2e7897e61c50163bb0758

.agents/notes/implemented/architecture/2026-07-31-code-runtime-portable-identifier-seam.md

@@ -0,0 +1,44 @@
+# Agent Note: the code-runtime seam owns portable-identifier exclusions
+
+Status: implemented
+
+English | [中文](2026-07-31-code-runtime-portable-identifier-seam.zh.md)
+
+## Problem
+
+The code-runtime seam promises that a binding-namespace list valid on one backend is valid on every backend, so a Code Mode consumer can hand the same bindings to any registered runtime without knowing its language. The first backend, `dsh-code-runtime-worker`, privately owned the identifier rules that enforce part of that promise: an `IDENTIFIER` regex that allowed the JS-only `$`, a `RESERVED_WORDS` set holding only ECMAScript keywords, and a `RESERVED_ERROR_PROPERTIES` set of three JS `Error` slots. Those rules described the worker's own language, not the seam's portability contract.
+
+A second backend written against a different language (CPython, arriving in a later PR of this stack) would either re-declare its own rules — letting `lambda` pass the worker and fail Python, or `$tools` pass the worker and fail every non-JS backend — or import the worker's, inverting the dependency so the seam's implementation reached into a sibling implementation. Neither keeps the portability promise real: it would hold only for the backend a caller happened to test against.
+
+## Decision
+
+The seam package (`@deepseek-ai/dsh-code-runtime`) exports the portable-identifier exclusion contract as four named constants, and every backend imports them rather than re-declaring:
+
+- `PORTABLE_RESERVED_WORDS` — the union of ECMAScript and Python reserved words. A namespace global or error-class name matching any is refused on all backends, so `lambda` is refused even though it is a legal JS parameter name. Adding a language widens this union, which is a deliberate breaking review of existing binding names.
+- `RESERVED_BINDING_GLOBALS` — globals some backend owns in the program's namespace: `console` (the worker's log capture), `__dsh_main__`/`__builtins__`/`__name__` (the Python bootstrap's wrapper and seeded module globals), and `__debug__` (not a seeded slot but a CPython compile-time constant that rejects assignment, so an injected global under that name is unreachable — the same portability split by a different mechanism). Refused everywhere so a namespace list cannot pick a name that works on one backend and collides on another.
+- `RESERVED_ERROR_MEMBERS` — error-member names every backend refuses: the JS `Error` slots (`name`, `message`, `stack`) and Python's exception-protocol members (`args`, `with_traceback`, `add_note`).
+- `DUNDER_MEMBER` — the dunder-form regex (`__x__`, non-empty middle), refused as an error member wholesale because several are constrained CPython descriptors whose exact set is an interpreter-version detail.
+
+The seam also narrows the portable identifier subset to `[A-Za-z_][A-Za-z0-9_]*` (documented on `CodeBindingNamespace.global` and `CodeBindingErrorClass`), dropping the JS-only `$`. The worker consumes the shared constants directly by their seam names — `PORTABLE_RESERVED_WORDS` for both binding-global and error-class names, `RESERVED_BINDING_GLOBALS` for backend-owned slots, `RESERVED_ERROR_MEMBERS` plus `DUNDER_MEMBER` for error members — with no local re-alias; its `IDENTIFIER` regex loses `$`.
+
+The constants live at the seam even though only one backend ships in this PR: the whole point is that the contract is language-agnostic and owned above any single language. A backend that violated it would be the bug, and the shared set is where a reviewer looks to see what "portable" means.
+
+## Scope
+
+This PR delivers only the seam extension and the worker's adoption of it. No Python backend, `py-types` renderer, or Code Mode language dispatch ships here — they are later PRs in the stack that depend on these exports. The seam README's worker-only wording is left unchanged for the same reason: linking to a `dsh-code-runtime-python` README that does not yet exist would break the dead-link gate.
+
+`RESERVED_BINDING_GLOBALS` currently encodes the not-yet-merged Python bootstrap's concrete design: it seeds exactly `__builtins__`/`__name__` and wraps the program under `__dsh_main__`. The Python-backend PR that seeds any additional module global (`__doc__`, `__loader__`, `__spec__`, `__file__`, `__package__`, …) MUST widen this set in the same change, exactly as adding a language widens `PORTABLE_RESERVED_WORDS` — a name the bootstrap seeds but the set omits is the portability split this contract exists to prevent.
+
+## Alternatives considered
+
+**Each backend declares its own exclusions.** Rejected: it makes the portability promise per-backend. A binding list the caller tested on the worker could be refused by Python, which is exactly the split the seam exists to prevent.
+
+**The Python backend imports the worker's constants.** Rejected: it inverts the dependency — the seam's implementations would reach into a sibling implementation for a contract neither owns. The contract belongs above both, at the seam.
+
+**Keep `$` in the portable identifier subset.** Rejected: `$` is JS-only spelling. Allowing it would let `$tools` pass the worker and fail every non-JS backend, breaking portability for a purely cosmetic gain.
+
+## Consequences
+
+Bought: one place — the seam package — defines what a portable binding name is, and every backend enforces the same contract by import. A namespace list valid on one backend is valid on all, verifiably, not by coincidence of which backend the caller tested.
+
+Cost: existing worker callers using a `$`-containing global now fail identifier validation. Under the pre-release stance this is a corrected foundation, not a compatibility break to shim. The worker's seam-misuse tests gain cases for `$tools`, Python exception members (`args`), dunders (`__dict__`), and a Python-owned global (`__dsh_main__`), proving the shared set is enforced from the worker side.

.agents/notes/implemented/architecture/2026-07-31-code-runtime-portable-identifier-seam.zh.md

@@ -0,0 +1,44 @@
+# Agent Note：code-runtime seam 拥有可移植标识符排除集
+
+Status: implemented
+
+[English](2026-07-31-code-runtime-portable-identifier-seam.md) | 中文
+
+## Problem
+
+code-runtime seam 承诺：在一个后端上有效的绑定命名空间列表，在每个后端上都有效，因此 Code Mode 消费方可以把同一组绑定交给任何已注册的运行时，而不必知道它的语言。首个后端 `dsh-code-runtime-worker` 私自拥有了执行这项承诺一部分的标识符规则：一个允许 JS 专有 `$` 的 `IDENTIFIER` 正则、一个只含 ECMAScript 关键字的 `RESERVED_WORDS` 集合，以及一个含三个 JS `Error` 槽位的 `RESERVED_ERROR_PROPERTIES` 集合。这些规则描述的是 worker 自身的语言，而非 seam 的可移植性契约。
+
+一个针对不同语言（CPython，将在本 stack 后续 PR 中到来）编写的第二后端，要么重新声明自己的规则——让 `lambda` 通过 worker 却在 Python 上失败，或让 `$tools` 通过 worker 却在每个非 JS 后端上失败——要么导入 worker 的规则，从而反转依赖，使 seam 的一个实现伸手进入另一个兄弟实现。二者都无法让可移植承诺成真：它只对调用方恰好测试过的那个后端成立。
+
+## Decision
+
+seam 包（`@deepseek-ai/dsh-code-runtime`）以四个具名常量导出可移植标识符排除契约，每个后端导入它们而非重新声明：
+
+- `PORTABLE_RESERVED_WORDS`——ECMAScript 与 Python 保留字的联集。任何命名空间 global 或 error-class 名称匹配其中之一，都在所有后端上被拒绝，因此 `lambda` 即便是合法的 JS 参数名也被拒绝。新增一门语言即扩宽此联集，这是对现有绑定名称的一次有意的破坏性复审。
+- `RESERVED_BINDING_GLOBALS`——某个后端在程序命名空间中拥有的 global：`console`（worker 的日志捕获）、`__dsh_main__`/`__builtins__`/`__name__`（Python bootstrap 的包装器与预置模块 global），以及 `__debug__`（不是 seed 的槽位，而是 CPython 编译期常量，赋值会被拒，故以该名注入的 global 不可达——同一种可移植性分裂，只是机制不同）。在所有后端上被拒绝，使命名空间列表无法选到一个在某后端能用、在另一后端冲突的名称。
+- `RESERVED_ERROR_MEMBERS`——每个后端都拒绝的 error-member 名称：JS `Error` 槽位（`name`、`message`、`stack`）与 Python 异常协议成员（`args`、`with_traceback`、`add_note`）。
+- `DUNDER_MEMBER`——dunder 形式正则（`__x__`，非空中缀），作为 error member 被整体拒绝，因为其中若干是受约束的 CPython 描述符，其确切集合是解释器版本细节。
+
+seam 同时把可移植标识符子集收窄为 `[A-Za-z_][A-Za-z0-9_]*`（记录在 `CodeBindingNamespace.global` 与 `CodeBindingErrorClass` 上），去掉 JS 专有的 `$`。worker 直接以 seam 名消费这些共享常量——binding-global 与 error-class 名称用 `PORTABLE_RESERVED_WORDS`、后端拥有槽位用 `RESERVED_BINDING_GLOBALS`、error member 用 `RESERVED_ERROR_MEMBERS` 加 `DUNDER_MEMBER`——不再本地起别名；其 `IDENTIFIER` 正则去掉 `$`。
+
+尽管本 PR 只交付一个后端，这些常量仍置于 seam：要点正是该契约与语言无关，且拥有权在任何单一语言之上。违反它的后端才是 bug，而共享集合正是复审者查看"可移植"含义的地方。
+
+## Scope
+
+本 PR 只交付 seam 扩展与 worker 对它的采用。这里不交付任何 Python 后端、`py-types` 渲染器或 Code Mode 的语言分发——它们是本 stack 中依赖这些导出的后续 PR。seam README 中仅描述 worker 的措辞保持不变，理由相同：链接到一个尚不存在的 `dsh-code-runtime-python` README 会破坏死链 gate。
+
+`RESERVED_BINDING_GLOBALS` 当前编码了尚未合并的 Python bootstrap 的具体设计：它恰好 seed `__builtins__`/`__name__`，并把程序包装在 `__dsh_main__` 之下。任何 seed 额外模块 global（`__doc__`、`__loader__`、`__spec__`、`__file__`、`__package__` 等）的 Python 后端 PR 必须在同一改动中扩宽此集合，正如新增一门语言即扩宽 `PORTABLE_RESERVED_WORDS`——bootstrap 会 seed 却不在集合中的名称，正是本契约要防止的可移植性分裂。
+
+## Alternatives considered
+
+**每个后端声明自己的排除集。** 拒绝：这让可移植承诺变成逐后端成立。调用方在 worker 上测过的绑定列表可能被 Python 拒绝，而这正是 seam 存在要防止的分裂。
+
+**Python 后端导入 worker 的常量。** 拒绝：这反转依赖——seam 的实现会为一个二者都不拥有的契约伸手进入兄弟实现。契约属于二者之上，即 seam。
+
+**在可移植标识符子集中保留 `$`。** 拒绝：`$` 是 JS 专有拼写。允许它会让 `$tools` 通过 worker 却在每个非 JS 后端上失败，为纯粹表面的好处破坏可移植性。
+
+## Consequences
+
+获得：一个地方——seam 包——定义什么是可移植绑定名称，每个后端通过导入执行同一契约。在一个后端上有效的命名空间列表在所有后端上都有效，这是可验证的，而非取决于调用方测试了哪个后端的巧合。
+
+代价：现有使用含 `$` global 的 worker 调用方现在会在标识符校验时失败。在预发布立场下这是一次被纠正的地基，而非需要 shim 的兼容性破坏。worker 的 seam-misuse 测试新增了 `$tools`、Python 异常成员（`args`）、dunder（`__dict__`）与一个 Python 拥有的 global（`__dsh_main__`）等用例，从 worker 侧证明共享集合被执行。

docs/cordis-catalog/services.md

@@ -398,7 +398,7 @@ abstract run(request: CodeRunRequest): Promise<CodeRunResult>
 
 Types: [CodeRunRequest](../core-data-structures/code-runtime.md) · [CodeRunResult](../core-data-structures/code-runtime.md)
 
-Source: [`packages/code-runtime/code-runtime/src/index.ts:33`](../../packages/code-runtime/code-runtime/src/index.ts)
+Source: [`packages/code-runtime/code-runtime/src/index.ts:104`](../../packages/code-runtime/code-runtime/src/index.ts)
 
 ## `ctx.commands` — `CommandService`
 

docs/core-data-structures/code-runtime.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/core-data-structures/code-runtime.md
-code-runtime.md: 24127dafbd4a202b6764b55319ec404e77391929
-code-runtime.zh.md: 35f06f2b48bfd3af6ccac6d9a4dd366ea9ec0c92
+code-runtime.md: fbce7d812b7609716fb43ae01610253008e0a92c
+code-runtime.zh.md: 700146cfaa9cfab37ec4d85e550020acf1d9f294

docs/core-data-structures/code-runtime.md

@@ -72,9 +72,14 @@ Each `CodeBindingNamespace` becomes one global object of async callables inside
  * of a particular consumer such as Code Mode.
  */
 interface CodeBindingErrorClass {
-  /** Constructor global and resulting `Error.name` (must be a usable JS identifier). */
+  /** Constructor global and resulting `Error.name`; same portable identifier rule as {@link CodeBindingNamespace.global}. */
   name: string
-  /** Non-empty own property for the member name; cannot replace `name`, `message`, or `stack`. */
+  /**
+   * Non-empty own property for the member name. The portable exclusion set is
+   * `RESERVED_ERROR_MEMBERS` plus dunder-form names (`__x__`, non-empty
+   * middle), enforced identically by every backend; any other name —
+   * identifiers or not — is accepted everywhere.
+   */
   memberNameProperty: string
 }
 ```
@@ -88,7 +93,16 @@ interface CodeBindingErrorClass {
  * collisions.
  */
 interface CodeBindingNamespace {
-  /** The global identifier the program sees (must be a valid JS identifier). */
+  /**
+   * The global identifier the program sees. Must match the LANGUAGE-PORTABLE
+   * identifier subset `[A-Za-z_][A-Za-z0-9_]*` and no language's reserved
+   * words, so the same namespace list works against every backend regardless
+   * of `language` — a JS-only spelling like `$tools` is rejected by design,
+   * not just by the Python backend. Names that satisfy the identifier rule but
+   * name a backend-owned slot (`RESERVED_BINDING_GLOBALS`, e.g. `console`,
+   * `__dsh_main__`) are also refused everywhere; see its declaration for the
+   * exact set and why each entry is reserved.
+   */
   global: string
   /** The callable members, keyed by the exact name the program calls. */
   functions: Record<string, CodeBindingFunction>

docs/core-data-structures/code-runtime.zh.md

@@ -72,9 +72,14 @@ interface CodeRunResult {
  * of a particular consumer such as Code Mode.
  */
 interface CodeBindingErrorClass {
-  /** Constructor global and resulting `Error.name` (must be a usable JS identifier). */
+  /** Constructor global and resulting `Error.name`; same portable identifier rule as {@link CodeBindingNamespace.global}. */
   name: string
-  /** Non-empty own property for the member name; cannot replace `name`, `message`, or `stack`. */
+  /**
+   * Non-empty own property for the member name. The portable exclusion set is
+   * `RESERVED_ERROR_MEMBERS` plus dunder-form names (`__x__`, non-empty
+   * middle), enforced identically by every backend; any other name —
+   * identifiers or not — is accepted everywhere.
+   */
   memberNameProperty: string
 }
 ```
@@ -88,7 +93,16 @@ interface CodeBindingErrorClass {
  * collisions.
  */
 interface CodeBindingNamespace {
-  /** The global identifier the program sees (must be a valid JS identifier). */
+  /**
+   * The global identifier the program sees. Must match the LANGUAGE-PORTABLE
+   * identifier subset `[A-Za-z_][A-Za-z0-9_]*` and no language's reserved
+   * words, so the same namespace list works against every backend regardless
+   * of `language` — a JS-only spelling like `$tools` is rejected by design,
+   * not just by the Python backend. Names that satisfy the identifier rule but
+   * name a backend-owned slot (`RESERVED_BINDING_GLOBALS`, e.g. `console`,
+   * `__dsh_main__`) are also refused everywhere; see its declaration for the
+   * exact set and why each entry is reserved.
+   */
   global: string
   /** The callable members, keyed by the exact name the program calls. */
   functions: Record<string, CodeBindingFunction>

packages/code-runtime/code-runtime-worker/src/index.ts

@@ -13,7 +13,7 @@ import { fileURLToPath } from 'node:url'
 import { Context } from 'cordis'
 import z from 'schemastery'
 import { MAX_TIMER_DELAY_MS } from '@deepseek-ai/dsh-timeout'
-import { CodeRuntime } from '@deepseek-ai/dsh-code-runtime'
+import { CodeRuntime, DUNDER_MEMBER, PORTABLE_RESERVED_WORDS, RESERVED_BINDING_GLOBALS, RESERVED_ERROR_MEMBERS } from '@deepseek-ai/dsh-code-runtime'
 import type { CodeBindingNamespace, CodeJsonValue, CodeRunFailure, CodeRunRequest, CodeRunResult } from '@deepseek-ai/dsh-code-runtime'
 import { snapshotJsonValue } from '@deepseek-ai/dsh-session'
 import type { ReplyMessage, WorkerBootData, WorkerToHost } from './protocol.ts'
@@ -65,20 +65,12 @@ const ELU_POLL_INTERVAL_MS = 25
 /** Smallest cap that can represent the counted payloads: an empty logs array plus an empty JSON failure message. */
 const MIN_OUTPUT_BYTES = 4
 
-/** ECMAScript reserved words that cannot be async-function parameter names — rejected as binding globals. */
-const RESERVED_WORDS = new Set([
-  'await', 'break', 'case', 'catch', 'class', 'const', 'continue', 'debugger', 'default', 'delete', 'do',
-  'else', 'enum', 'export', 'extends', 'false', 'finally', 'for', 'function', 'if', 'import', 'in',
-  'instanceof', 'new', 'null', 'return', 'super', 'switch', 'this', 'throw', 'true', 'try', 'typeof',
-  'var', 'void', 'while', 'with', 'yield', 'let', 'static', 'implements', 'interface', 'package',
-  'private', 'protected', 'public', 'arguments', 'eval',
-])
-
-/** Valid async-function parameter name (the binding global becomes one). */
-const IDENTIFIER = /^[A-Za-z_$][A-Za-z0-9_$]*$/
-
-/** Error properties whose binding-member replacement would destroy the promised Error contract. */
-const RESERVED_ERROR_PROPERTIES = new Set(['name', 'message', 'stack'])
+/**
+ * The seam's language-portable identifier subset (see
+ * `CodeBindingNamespace.global`): no `$`, which is JS-only spelling — the same
+ * namespace list must be usable against every backend regardless of language.
+ */
+const IDENTIFIER = /^[A-Za-z_][A-Za-z0-9_]*$/
 
 /**
  * The shell a program is wrapped in for the type-strip, matching the
@@ -328,10 +320,19 @@ export class WorkerCodeRuntime extends CodeRuntime {
   private validateBindings(request: CodeRunRequest): Map<string, CodeBindingNamespace> {
     const bindings = new Map<string, CodeBindingNamespace>()
     for (const namespace of request.bindings) {
-      if (!IDENTIFIER.test(namespace.global) || RESERVED_WORDS.has(namespace.global)) {
+      if (!IDENTIFIER.test(namespace.global) || PORTABLE_RESERVED_WORDS.has(namespace.global)) {
         throw new Error(`dsh-code-runtime-worker: binding global ${JSON.stringify(namespace.global)} is not a usable identifier`)
       }
-      if (namespace.global === 'console' || bindings.has(namespace.global)) {
+      // RESERVED_BINDING_GLOBALS is the seam's shared backend-owned set:
+      // `console` is THIS backend's log-capture slot; the dunder entries exist
+      // for the Python side — its seeded/wrapped slots plus the `__debug__`
+      // compile-time constant — refused here too so the namespace list stays
+      // portable across backends. The seam declaration is the single home for
+      // why each entry is reserved.
+      if (RESERVED_BINDING_GLOBALS.has(namespace.global)) {
+        throw new Error(`dsh-code-runtime-worker: reserved binding global ${JSON.stringify(namespace.global)}`)
+      }
+      if (bindings.has(namespace.global)) {
         throw new Error(`dsh-code-runtime-worker: duplicate binding global ${JSON.stringify(namespace.global)}`)
       }
       bindings.set(namespace.global, namespace)
@@ -341,13 +342,17 @@ export class WorkerCodeRuntime extends CodeRuntime {
     for (const namespace of request.bindings) {
       const descriptor = namespace.errorClass
       if (!descriptor) continue
-      if (!IDENTIFIER.test(descriptor.name) || RESERVED_WORDS.has(descriptor.name)) {
+      if (!IDENTIFIER.test(descriptor.name) || PORTABLE_RESERVED_WORDS.has(descriptor.name)) {
         throw new Error(`dsh-code-runtime-worker: binding error class ${JSON.stringify(descriptor.name)} is not a usable identifier`)
       }
-      if (descriptor.name === 'console' || bindings.has(descriptor.name) || errorClassNames.has(descriptor.name)) {
+      if (RESERVED_BINDING_GLOBALS.has(descriptor.name)) {
+        throw new Error(`dsh-code-runtime-worker: reserved binding global ${JSON.stringify(descriptor.name)}`)
+      }
+      if (bindings.has(descriptor.name) || errorClassNames.has(descriptor.name)) {
         throw new Error(`dsh-code-runtime-worker: duplicate injected global ${JSON.stringify(descriptor.name)}`)
       }
-      if (descriptor.memberNameProperty.length === 0 || RESERVED_ERROR_PROPERTIES.has(descriptor.memberNameProperty)) {
+      const member = descriptor.memberNameProperty
+      if (member.length === 0 || RESERVED_ERROR_MEMBERS.has(member) || DUNDER_MEMBER.test(member)) {
         throw new Error(`dsh-code-runtime-worker: binding error member property ${JSON.stringify(descriptor.memberNameProperty)} is not usable`)
       }
       errorClassNames.add(descriptor.name)

packages/code-runtime/code-runtime-worker/tests/runtime.spec.ts

@@ -787,7 +787,17 @@ describe('WorkerCodeRuntime — seam misuse and lifecycle', () => {
     const cases: [string, RegExp][] = [
       ['not valid!', /not a usable identifier/],
       ['await', /not a usable identifier/],
-      ['console', /duplicate binding global/],
+      // `$tools` is legal JS but outside the seam's language-portable subset:
+      // the same namespace list must work against every backend's language.
+      ['$tools', /not a usable identifier/],
+      // `a$b` pins the second character class too: the old identifier regex
+      // `[A-Za-z0-9_$]*` would have accepted a `$` after the first character.
+      ['a$b', /not a usable identifier/],
+      // `lambda` is a Python keyword, refused here directly (not just
+      // transitively) so the worker's adoption of PORTABLE_RESERVED_WORDS is
+      // its own regression, symmetric with the `$tools` case.
+      ['lambda', /not a usable identifier/],
+      ['console', /reserved binding global/],
     ]
     for (const [global, message] of cases) {
       await expect(runtime.run({ program: 'return 1', bindings: [{ global, functions: {} }] })).rejects.toThrow(message)
@@ -814,7 +824,7 @@ describe('WorkerCodeRuntime — seam misuse and lifecycle', () => {
 
     await expect(run([namespace('tools', 'not valid!')])).rejects.toThrow(/error class.*not a usable identifier/)
     await expect(run([namespace('tools', 'await')])).rejects.toThrow(/error class.*not a usable identifier/)
-    await expect(run([namespace('tools', 'console')])).rejects.toThrow(/duplicate injected global/)
+    await expect(run([namespace('tools', 'console')])).rejects.toThrow(/reserved binding global/)
     await expect(run([namespace('tools', 'tools')])).rejects.toThrow(/duplicate injected global/)
     await expect(run([
       namespace('tools', 'CallError'),
@@ -822,6 +832,14 @@ describe('WorkerCodeRuntime — seam misuse and lifecycle', () => {
     ])).rejects.toThrow(/duplicate injected global/)
     await expect(run([namespace('tools', 'CallError', '')])).rejects.toThrow(/member property.*not usable/)
     await expect(run([namespace('tools', 'CallError', 'message')])).rejects.toThrow(/member property.*not usable/)
+    // The shared exclusion set covers Python's exception-protocol members and
+    // dunders too, so the same errorClass is valid (or not) on every backend.
+    await expect(run([namespace('tools', 'CallError', 'args')])).rejects.toThrow(/member property.*not usable/)
+    await expect(run([namespace('tools', 'CallError', '__dict__')])).rejects.toThrow(/member property.*not usable/)
+    // The Python backend's owned globals are refused here too (shared
+    // RESERVED_BINDING_GLOBALS), keeping namespace lists backend-portable.
+    await expect(runtime.run({ program: 'return 1', bindings: [{ global: '__dsh_main__', functions: {} }] }))
+      .rejects.toThrow(/reserved binding global/)
   })
 
   it('rejects config values that are not positive numbers', async () => {

packages/code-runtime/code-runtime/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/code-runtime/code-runtime/README.md
-README.md: e9641041af76b60606f999783f29224d8d79c743
-README.zh.md: cc97b6b6cf7c8c5aedb58e40d06ee6dd962ac3b2
+README.md: bb1c20d00a260f643f601c42c6e48722437d5aab
+README.zh.md: 15fbcecf77b2318acf3b09101802cd032ae426d2

packages/code-runtime/code-runtime/README.md

@@ -20,6 +20,8 @@ Semantics every implementation must honor (contract details in the class JSDoc):
 
 `CodeRunRequest` (`program`, `bindings`, `signal?`) carries everything the runtime acts on — defaulting (time budgets and outer-output cap) is the implementation's validated config, never a hidden `??` inside `run()`. `bindings` is a list of `CodeBindingNamespace`s (`global` + `functions` + optional `errorClass`), each exposed to the program as one global object of async callables returning `CodeJsonValue`, the seam-local structural equivalent of canonical `JsonValue` that keeps this interface package independent of sessions. An `errorClass` descriptor names a real program-global constructor and the own property that receives the rejected member name; runtimes remain independent of consumer terms such as `ToolCallError`. `CodeRunResult` reports the lossless JSON completion `value?`, ordered `logs: string[]`, and the `error?` (`CodeRunFailure`: `kind` + model-feedable `message`). See `src/types.ts` for the full contracts.
 
+Binding-global and error-class names are **language-portable**: they must match the identifier subset `[A-Za-z_][A-Za-z0-9_]*` (no JS-only `$`) and clear the seam-exported exclusion sets, so one `bindings` list is valid against every backend regardless of its `language`. The package exports the contract every backend enforces — `PORTABLE_RESERVED_WORDS` (ECMAScript ∪ Python reserved words), `RESERVED_BINDING_GLOBALS` (backend-owned globals such as `console`), `RESERVED_ERROR_MEMBERS` and `DUNDER_MEMBER` (error-member exclusions) — so a name like `$tools`, `lambda`, or `__dsh_main__` makes `run()` reject as seam misuse on any backend, not just some. See `src/index.ts` for the exact sets and rationale.
+
 ## Model Experience
 
 Indirectly, through Code Mode in `dsh-tools`, which exposes `run_code` and returns program logs, values, or failures as retained tool-result tokens.

packages/code-runtime/code-runtime/README.zh.md

@@ -20,6 +20,8 @@
 
 `CodeRunRequest`（`program`、`bindings`、`signal?`）携带运行时操作所需的全部内容；默认值解析（时间预算与外层输出上限）属于实现的已验证配置，绝不能是隐藏的 `??`，更不能藏在 `run()` 内部。`bindings` 是 `CodeBindingNamespace` 列表（`global` + `functions` + 可选 `errorClass`）；每个命名空间会作为一个由异步可调用函数组成的全局对象公开给程序，这些函数返回 `CodeJsonValue`。后者是 seam 本地、与规范 `JsonValue` 结构等价的类型，使接口包保持独立于会话。`errorClass` 描述符点名真实的程序全局构造器，以及用于接收被拒绝成员名称的自有属性；运行时不依赖 `ToolCallError` 等消费方术语。`CodeRunResult` 报告无损 JSON 完成值 `value?`、有序的 `logs: string[]` 和 `error?`（`CodeRunFailure`：`kind` + 可反馈给模型的 `message`）。完整契约见 `src/types.ts`。
 
+binding-global 与 error-class 名称是**语言可移植**的：必须匹配标识符子集 `[A-Za-z_][A-Za-z0-9_]*`（不含 JS 专有的 `$`）并通过 seam 导出的排除集，因此同一份 `bindings` 列表对每个后端都有效，无论其 `language` 为何。本包导出每个后端都执行的契约——`PORTABLE_RESERVED_WORDS`（ECMAScript ∪ Python 保留字）、`RESERVED_BINDING_GLOBALS`（如 `console` 等后端拥有的 global）、`RESERVED_ERROR_MEMBERS` 与 `DUNDER_MEMBER`（error-member 排除）——因此 `$tools`、`lambda`、`__dsh_main__` 之类的名称会让 `run()` 在任何后端上作为 seam 误用而 reject，而非只在某些后端。确切集合与理由见 `src/index.ts`。
+
 ## 模型体验
 
 通过 `dsh-tools` 中的 Code Mode 间接提供；后者公开 `run_code`，并将程序日志、值或失败作为保留的工具结果 token 返回。

packages/code-runtime/code-runtime/src/index.ts

@@ -17,6 +17,77 @@ export type {
   CodeRunResult,
 } from './types.ts'
 
+/**
+ * Binding globals EVERY backend refuses because SOME backend owns the slot in
+ * the program's namespace: `console` (the worker's log capture), and
+ * `__dsh_main__`/`__builtins__`/`__name__` (the Python backend's bootstrap
+ * wrapper and seeded module globals — that backend is a later PR in this
+ * stack, see the [portable-identifier Agent
+ * Note](../../../../.agents/notes/implemented/architecture/2026-07-31-code-runtime-portable-identifier-seam.md)),
+ * and `__debug__`. One shared set — rather than each backend refusing only its
+ * own slots — keeps the portability promise real: a namespace list valid on
+ * one backend is valid on all, so a caller cannot pick a name that works on
+ * the worker and collides on Python (or vice versa). `__name__` et al. ARE
+ * valid portable identifiers, so the identifier rule on
+ * `CodeBindingNamespace.global` never rejects them — hence this explicit set.
+ * (Error members differ: {@link DUNDER_MEMBER} refuses every dunder form
+ * wholesale; binding globals refuse only the names listed here.) `__debug__`
+ * is listed for a different reason than a collision: CPython compiles a bare
+ * `__debug__` reference to the constant `True` and rejects any assignment to
+ * the name at COMPILE time, so an injected global under that name is
+ * unreachable from the program — accepted by validation, unusable on the
+ * Python backend, which is exactly the split the shared set exists to prevent.
+ */
+export const RESERVED_BINDING_GLOBALS: ReadonlySet<string> = new Set([
+  'console',
+  '__dsh_main__', '__builtins__', '__name__', '__debug__',
+])
+
+/**
+ * `CodeBindingErrorClass.memberNameProperty` names EVERY backend refuses, as
+ * one shared contract so a request valid on one backend is valid on all. The
+ * JS `Error` exclusions (`name`, `message`, `stack`) and Python's
+ * exception-protocol members (`args`, `with_traceback`, `add_note`) are
+ * listed by name; dunder-form names (`__x__`, non-empty middle) are refused
+ * wholesale — several are constrained CPython descriptors whose `setattr`
+ * raises while constructing the rejection, and the exact set is an interpreter
+ * version detail. Any other non-empty own property name is accepted everywhere.
+ */
+export const RESERVED_ERROR_MEMBERS: ReadonlySet<string> = new Set([
+  'name', 'message', 'stack',
+  'args', 'with_traceback', 'add_note',
+])
+
+/**
+ * Dunder form (`__x__`, non-empty middle): object-protocol slots in Python,
+ * refused as {@link RESERVED_ERROR_MEMBERS | error members} on every backend.
+ */
+export const DUNDER_MEMBER = /^__.+__$/
+
+/**
+ * Reserved words of every portable target language (ECMAScript ∪ Python),
+ * refused as {@link CodeBindingNamespace.global} / error-class names by all
+ * backends. Python is a portability target here even though only the
+ * TypeScript worker ships in this PR (the CPython backend is a later PR in the
+ * stack). The portable-identifier contract promises a namespace list valid
+ * on one backend is valid on every backend; a per-language check would let
+ * `lambda` pass the TypeScript backend and fail the Python one. Extending the
+ * seam with a new language means widening this union (a breaking review of
+ * existing binding names, by design).
+ */
+export const PORTABLE_RESERVED_WORDS: ReadonlySet<string> = new Set([
+  // ECMAScript reserved words and reserved-in-strict-mode names.
+  'await', 'break', 'case', 'catch', 'class', 'const', 'continue', 'debugger', 'default', 'delete', 'do',
+  'else', 'enum', 'export', 'extends', 'false', 'finally', 'for', 'function', 'if', 'import', 'in',
+  'instanceof', 'new', 'null', 'return', 'super', 'switch', 'this', 'throw', 'true', 'try', 'typeof',
+  'var', 'void', 'while', 'with', 'yield', 'let', 'static', 'implements', 'interface', 'package',
+  'private', 'protected', 'public', 'arguments', 'eval',
+  // Python 3.x keywords and soft keywords not already above ('type' and '_'
+  // are soft keywords: legal names in practice, reserved here for safety).
+  'False', 'None', 'True', 'and', 'as', 'assert', 'async', 'def', 'del', 'elif', 'except', 'from',
+  'global', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise', 'match', 'type', '_',
+])
+
 declare module 'cordis' {
   interface Context {
     codeRuntime: CodeRuntime

packages/code-runtime/code-runtime/src/types.ts

@@ -28,9 +28,14 @@ export type CodeJsonValue = null | boolean | number | string | CodeJsonValue[] |
  * of a particular consumer such as Code Mode.
  */
 export interface CodeBindingErrorClass {
-  /** Constructor global and resulting `Error.name` (must be a usable JS identifier). */
+  /** Constructor global and resulting `Error.name`; same portable identifier rule as {@link CodeBindingNamespace.global}. */
   name: string
-  /** Non-empty own property for the member name; cannot replace `name`, `message`, or `stack`. */
+  /**
+   * Non-empty own property for the member name. The portable exclusion set is
+   * `RESERVED_ERROR_MEMBERS` plus dunder-form names (`__x__`, non-empty
+   * middle), enforced identically by every backend; any other name —
+   * identifiers or not — is accepted everywhere.
+   */
   memberNameProperty: string
 }
 
@@ -42,7 +47,16 @@ export interface CodeBindingErrorClass {
  * collisions.
  */
 export interface CodeBindingNamespace {
-  /** The global identifier the program sees (must be a valid JS identifier). */
+  /**
+   * The global identifier the program sees. Must match the LANGUAGE-PORTABLE
+   * identifier subset `[A-Za-z_][A-Za-z0-9_]*` and no language's reserved
+   * words, so the same namespace list works against every backend regardless
+   * of `language` — a JS-only spelling like `$tools` is rejected by design,
+   * not just by the Python backend. Names that satisfy the identifier rule but
+   * name a backend-owned slot (`RESERVED_BINDING_GLOBALS`, e.g. `console`,
+   * `__dsh_main__`) are also refused everywhere; see its declaration for the
+   * exact set and why each entry is reserved.
+   */
   global: string
   /** The callable members, keyed by the exact name the program calls. */
   functions: Record<string, CodeBindingFunction>

packages/code-runtime/code-runtime/tests/reserved.spec.ts

@@ -0,0 +1,57 @@
+import { describe, expect, it } from 'vitest'
+import {
+  DUNDER_MEMBER,
+  PORTABLE_RESERVED_WORDS,
+  RESERVED_BINDING_GLOBALS,
+  RESERVED_ERROR_MEMBERS,
+} from '@deepseek-ai/dsh-code-runtime'
+
+/**
+ * The seam owns the portable-identifier exclusion sets so every backend
+ * enforces one contract: a namespace list valid on one backend is valid on
+ * all. These assertions pin the shared membership backends import rather than
+ * re-declare.
+ */
+describe('seam-owned portable identifier exclusions', () => {
+  it('RESERVED_BINDING_GLOBALS covers each backend-owned slot', () => {
+    expect(RESERVED_BINDING_GLOBALS.has('console')).toBe(true)
+    expect(RESERVED_BINDING_GLOBALS.has('__dsh_main__')).toBe(true)
+    expect(RESERVED_BINDING_GLOBALS.has('__builtins__')).toBe(true)
+    expect(RESERVED_BINDING_GLOBALS.has('__name__')).toBe(true)
+    expect(RESERVED_BINDING_GLOBALS.has('__debug__')).toBe(true)
+    expect(RESERVED_BINDING_GLOBALS.has('tools')).toBe(false)
+  })
+
+  it('RESERVED_ERROR_MEMBERS covers the JS Error and Python exception-protocol members', () => {
+    for (const name of ['name', 'message', 'stack', 'args', 'with_traceback', 'add_note']) {
+      expect(RESERVED_ERROR_MEMBERS.has(name)).toBe(true)
+    }
+    expect(RESERVED_ERROR_MEMBERS.has('code')).toBe(false)
+  })
+
+  it('DUNDER_MEMBER matches dunder-form names only', () => {
+    expect(DUNDER_MEMBER.test('__dict__')).toBe(true)
+    expect(DUNDER_MEMBER.test('__init__')).toBe(true)
+    expect(DUNDER_MEMBER.test('_private')).toBe(false)
+    expect(DUNDER_MEMBER.test('name')).toBe(false)
+    expect(DUNDER_MEMBER.test('__mid')).toBe(false)
+    // `__` has an empty middle — not a real CPython dunder, so not matched.
+    expect(DUNDER_MEMBER.test('__')).toBe(false)
+    // `____` also has an empty middle between the two `__` pairs — not matched.
+    expect(DUNDER_MEMBER.test('____')).toBe(false)
+    // A single character between the pairs is the shortest real dunder form.
+    expect(DUNDER_MEMBER.test('__x__')).toBe(true)
+  })
+
+  it('PORTABLE_RESERVED_WORDS is the union of ECMAScript and Python reserved words', () => {
+    // ECMAScript-only keyword.
+    expect(PORTABLE_RESERVED_WORDS.has('function')).toBe(true)
+    // Python-only keyword — refused here so the list stays portable.
+    expect(PORTABLE_RESERVED_WORDS.has('lambda')).toBe(true)
+    expect(PORTABLE_RESERVED_WORDS.has('nonlocal')).toBe(true)
+    // Shared keyword.
+    expect(PORTABLE_RESERVED_WORDS.has('class')).toBe(true)
+    // Ordinary identifier is not reserved.
+    expect(PORTABLE_RESERVED_WORDS.has('tools')).toBe(false)
+  })
+})