diff --git a/docs/rfc/INDEX.md b/docs/rfc/INDEX.md
index 39927e3095..0d5f12d636 100644
--- a/docs/rfc/INDEX.md
+++ b/docs/rfc/INDEX.md
@@ -42,7 +42,6 @@ Generated by `pnpm run gen-rfc-index` from the RFC tree — never edit by hand;
 |---|---|
 | [Deterministic tests, the replay invariant fixture, and race stress](proposed/testing/2026-06-11-deterministic-and-stress-testing.md) | 2026-06-11 |
 | [Mutation testing as the coverage counterweight](proposed/testing/2026-06-11-mutation-testing.md) | 2026-06-11 |
-| [Extract the ACP snapshot suite into a support package](proposed/testing/2026-07-08-shared-acp-snapshot-package.md) | 2026-07-08 |
 
 ## Implemented
 
@@ -165,6 +164,7 @@ Generated by `pnpm run gen-rfc-index` from the RFC tree — never edit by hand;
 | [Hook snapshot matrix — end-to-end goldens for both bridges](implemented/testing/2026-07-04-hook-snapshot-matrix.md) | 2026-07-04 |
 | [Single-source the acp-agent replay config](implemented/testing/2026-07-04-single-source-acp-replay-config.md) | 2026-07-04 |
 | [Pin request-header content in one snapshot scenario](implemented/testing/2026-07-06-pin-request-header-content-in-one-scenario.md) | 2026-07-06 |
+| [Extract the ACP snapshot suite into a support package](implemented/testing/2026-07-08-shared-acp-snapshot-package.md) | 2026-07-08 |
 
 ## Rejected
 
diff --git a/docs/rfc/implemented/testing/2026-07-08-shared-acp-snapshot-package.md b/docs/rfc/implemented/testing/2026-07-08-shared-acp-snapshot-package.md
new file mode 100644
index 0000000000..8c95c1f049
--- /dev/null
+++ b/docs/rfc/implemented/testing/2026-07-08-shared-acp-snapshot-package.md
@@ -0,0 +1,36 @@
+# RFC: Extract the ACP snapshot suite into a support package
+
+Status: implemented
+
+## Problem
+
+The ACP snapshot tier ([snapshot RFC](2026-06-19-acp-snapshot-tests.md)) was built from three modules living inside one example's test directory: `snapshot-harness.ts` (boot the real bin subprocess, drive it over ACP JSON-RPC, harvest the persisted logs), `snapshot-normalize.ts` (the pure golden normalizers), and the ~150-line scenario body plus fixture guards in `acp.snapshot.ts` (record/replay modes, the stdout-golden and log compares, the pinned-header uniformity guard, the orphan/required-file/single-pin meta-tests).
+
+A second ACP example wanting snapshot coverage — the sandbox/approval composition is the immediate consumer — could only copy those modules, forking exactly the logic that must not drift: record write-back, header scrubbing, child-session harvest ordering. The spawn/client glue was already triplicated across `acp.e2e.ts`, `hooks.e2e.ts`, and the harness (`TODO(acp-test-harness)`). Location also decided test rigor: the per-file 100% coverage gate measures `packages/*/*/src` only, so none of this machinery was measured — the same gap that had moved `dsh-llm-replay` out of `examples/` into [packages/support](../../../../packages/support/README.md). And the harness's ACP client hardcoded `requestPermission → cancelled`, so an approval round-trip — the headline behavior of the sandbox composition — could not be expressed at the snapshot tier at all.
+
+## Decision
+
+The machinery lives in [`packages/support/acp-snapshot`](../../../../packages/support/acp-snapshot/README.md) (`@deepseek-ai/dsh-acp-snapshot`); an example's `*.snapshot.ts` is its scenario table, its agent paths, and one factory call, over its own `snapshots/` fixtures and `cordis.snapshot.yml` overlay ([single-source replay config](2026-07-04-single-source-acp-replay-config.md)). Reading `DSH_SNAPSHOT` stays at that edge — the library takes a resolved `mode`.
+
+**`src/harness.ts`** — `runScenario` and the input-script/result types, parameterized by an `AgentUnderTest` (`binScript`, `configPath`, `tsconfigPath`; absolute paths the consuming suite resolves from its own `import.meta.url`). The client's `session/request_permission` handler consumes an optional `InputScript.permissionAnswers` FIFO queue, each entry selecting by option **kind** (ids are agent-issued randoms a committed script cannot know; kinds are the ACP-stable vocabulary, mapped to the offered `optionId` at answer time); an absent or exhausted queue answers `cancelled`, and a kind the request never offered fails loud. This is what lets an approval suite drive allow/reject round-trips deterministically from `input.json`.
+
+**`src/normalize.ts`** — the pure normalizers, hook-free by policy: when a future event carries a new volatile field (an approval duration, say), the shared normalizer learns it in the same change, keeping one home for what "normalized" means rather than per-suite scrub extensions.
+
+**`src/suite.ts`** — the `Scenario` type and `defineAcpSnapshotSuite(options)`, registering the per-scenario compares, record-mode fixture write-back, the header pin with its live uniformity guard, and the fixture guard block (no orphan scenario dirs, required files present, exactly one pin, non-pinning fixtures are `scrubRequestHeaders` fixed points). The pinned-header contract ([pinned-header RFC](2026-07-06-pin-request-header-content-in-one-scenario.md)) is per-suite: each suite flags exactly one `pinsHeader` scenario (the factory throws on zero, a meta-test rejects more than one; WHICH scenario pins is the table's reviewable choice), and the uniformity guard compares only that suite's sessions. The pure helpers (`childFixturePaths`, `fixtureContext`, `normalizedHeaders`, `headerDeltaCount`) are exported for direct unit coverage.
+
+## Alternatives considered
+
+- **Copy the modules into each example** — the fork this RFC exists to prevent: the record/guard logic is exactly the code that must stay byte-identical across suites, and examples are outside the coverage gate, so each copy is also unmeasured.
+- **A shared module directory under `examples/`** — keeps the code outside the coverage gate and forces relative imports across example boundaries, against the package-name import convention; `examples/` leaves stay thin by design.
+- **A `/testing` subpath export of `dsh-acp-agent`** — couples test infrastructure into a product package's surface and dependency set; `packages/support/` exists precisely for real-but-lower-compatibility dev/test packages, with `dsh-llm-replay` as the precedent this package completes.
+- **Export raw test-body functions instead of a suite factory** — each example would re-own the `describe`/`it` skeleton (~80 lines of registration boilerplate per suite) for no flexibility gain; the factory keeps consumers to a scenario table plus one call, and the exported pure helpers preserve unit-testability inside the factory design.
+- **An injectable ACP `Client` factory instead of declarative `permissionAnswers`** — maximally flexible, but it leaks SDK client construction to every consumer and reopens per-example drift in exactly the layer being unified; a declarative queue keeps `input.json` the single scripting surface and stays golden-normalizable.
+- **Generalize beyond ACP (a transport-agnostic snapshot harness)** — no second transport exists; the harness is ACP-shaped end to end (SDK client, JSON-RPC frames, `session/update` waiters), and a speculative abstraction would be a seam split ahead of any consumer.
+
+## Testing
+
+Extraction parity was proven mechanically: after the move, `pnpm run test:snapshot` matched the base commit's result with zero byte changes under `examples/acp-agent/tests/snapshots/`. The package's `src/` holds per-file 100% statements/branches/functions/lines under the gating unit run, driven through the REAL spawn path by a scripted fake ACP bin (`tests/fixtures/fake-acp-agent.ts`, behavior scripted per scenario via a `behavior.json` beside the fixture): `harness.spec.ts` covers every step op, both expect-error arms, the permission queue (selection, fallback, impossible-click), env forwarding, workspace seeding, and the harvest ordering/noise/fallback branches; `suite.spec.ts` runs the factory for real at collection time — a replay suite over committed synthetic fixtures and a record suite over a temp copy (write-back never touches the committed tree; `ACP_SNAPSHOT_SPEC_BOOTSTRAP=1` re-bootstraps it) — plus direct cases for the pure helpers. Two structurally unreachable guards carry reasoned `v8 ignore` comments. The fake bin substitutes the `session/new` cwd, not `process.cwd()`, into scripted logs, matching what the real bin's header carries (darwin realpaths `/var/folders/…` to `/private/var/folders/…`).
+
+## Consequences
+
+A new example gets the whole snapshot tier from a scenario table plus fixtures — the sandbox branch merges master down and adds its own suite (own pin scenario, own overlay, fixtures via `test:snapshot:record`, approvals via `permissionAnswers`). The costs: `suite.ts` imports vitest, so the package is importable only inside a vitest run — a shape no other package has, stated in its README; each suite pins its own ~8 KB header fixture (a genuinely distinct composition deserves its own pin; an identical one would be caught by that suite's uniformity guard); and the e2e launcher duplication remains (`TODO(acp-test-harness)`) — the harness is the extraction target when that migration lands.
diff --git a/docs/rfc/proposed/testing/2026-07-08-shared-acp-snapshot-package.md b/docs/rfc/proposed/testing/2026-07-08-shared-acp-snapshot-package.md
deleted file mode 100644
index 839e1d4542..0000000000
--- a/docs/rfc/proposed/testing/2026-07-08-shared-acp-snapshot-package.md
+++ /dev/null
@@ -1,54 +0,0 @@
-# RFC: Extract the ACP snapshot suite into a support package
-
-Status: proposed
-
-## Problem
-
-The ACP snapshot tier ([snapshot RFC](../../implemented/testing/2026-06-19-acp-snapshot-tests.md)) is built from three modules that live inside one example's test directory: `snapshot-harness.ts` (boot the real bin subprocess, drive it over ACP JSON-RPC, harvest the persisted logs), `snapshot-normalize.ts` (the pure golden normalizers), and the ~150-line scenario body plus fixture guards in [acp.snapshot.ts](../../../../examples/acp-agent/tests/acp.snapshot.ts) (record/replay modes, the stdout-golden and log compares, the pinned-header uniformity guard, the orphan/required-file/single-pin meta-tests).
-
-A second ACP example that wants snapshot coverage — the sandbox/approval composition is the immediate consumer — can only copy those modules, forking exactly the logic that must not drift: record write-back, header scrubbing, child-session harvest ordering. The spawn/client glue is already triplicated across [acp.e2e.ts](../../../../examples/acp-agent/tests/acp.e2e.ts), [hooks.e2e.ts](../../../../examples/acp-agent/tests/hooks.e2e.ts), and the harness, marked by `TODO(acp-test-harness)`.
-
-Location also decides test rigor: the per-file 100% coverage gate measures `packages/*/*/src` only, so none of this machinery is measured — the same gap that moved `dsh-llm-replay` out of `examples/` into [packages/support](../../../../packages/support/README.md). The harness's subprocess lifecycle, teardown, and harvest-ordering branches are exercised only transitively, when a live scenario happens to hit them.
-
-Finally, the harness's ACP client hardcodes `requestPermission → cancelled`, so an approval round-trip — the headline behavior of the sandbox composition — cannot be expressed at the snapshot tier at all. A new transcript surface must name its coverage at every tier at plan time; today the tier cannot express this one.
-
-## Proposal
-
-Create `packages/support/acp-snapshot` (`@deepseek-ai/dsh-acp-snapshot`), a support-tier package with three source modules; each example keeps only its scenario table, its `snapshots/` fixtures, its `cordis.snapshot.yml` overlay ([single-source replay config](../../implemented/testing/2026-07-04-single-source-acp-replay-config.md)), and the paths that identify its agent.
-
-**`src/harness.ts`** — `runScenario` and the input-script/result types, moved intact, with the module-level path constants replaced by an explicit `AgentUnderTest` parameter (`binScript`, `configPath`, `tsconfigPath`): defaulting stays at the seam's consumer, which resolves them from its own `import.meta.url`. The internal spawn/tee/SDK-client wiring is factored so the e2e launcher duplication can migrate onto it later; that migration is out of scope here and the `TODO(acp-test-harness)` stays until it lands.
-
-**`src/normalize.ts`** — the normalizers move verbatim with their spec. They stay hook-free: when a future event carries a new volatile field (an approval duration, say), the shared normalizer learns it in the same change, keeping one home for what "normalized" means rather than per-suite scrub extensions.
-
-**`src/suite.ts`** — the `Scenario` type and `defineAcpSnapshotSuite(options)`, which registers the per-scenario `describe`/`it` tree and the fixture guard tests. Options carry the resolved `mode: 'replay' | 'record'` — reading `DSH_SNAPSHOT` stays at the edge, in the example's `*.snapshot.ts`. The guard logic (no orphan scenario dirs, required fixture files, exactly one pin, non-pinning fixtures are `scrubRequestHeaders` fixed points) is exported as pure assertion functions the registered tests call one-line-each, so failure paths are unit-testable without meta-running vitest. The pinned-header contract ([pinned-header RFC](../../implemented/testing/2026-07-06-pin-request-header-content-in-one-scenario.md)) becomes per-suite: each suite flags exactly one `pinsHeader` scenario and its uniformity guard compares only that suite's sessions, which is the guard's existing scope.
-
-**Scripted permission answers** — `InputScript` gains an optional ordered `permissionAnswers` queue consumed by the harness client's `requestPermission`, each entry selecting a response by option **kind** (`allow_once`, `reject_once`, …); the harness maps kind to the agent-issued `optionId` at answer time, since ids are random per run while kinds are stable. An exhausted or absent queue falls back to today's `cancelled`, so existing scenarios and goldens are untouched. This is what lets a sandbox suite script an approval round-trip deterministically from `input.json`.
-
-Repo wiring follows the [adding-a-package cookbook](../../../cookbook/adding-a-package.md): manifest per the workspace constraints (cordis peer+dev, `private`, standard `files`), references in the root and build tsconfigs (the `@deepseek-ai/dsh-*` paths wildcard already covers `packages/support/*/src`), a row in the support group README, and explicit `@agentclientprotocol/sdk`/`vitest`/`tsx` dependencies instead of inherited-by-walk-up resolution. [docs/testing.md](../../../testing.md) generalizes "scenarios live under `examples/acp-agent/tests/snapshots/`" to the owning example's `tests/snapshots/`.
-
-Landing order is three commits on one PR: (1) the pure move plus parameterization, with `examples/acp-agent/tests/acp.snapshot.ts` collapsed to its scenario table and one `defineAcpSnapshotSuite` call; (2) the coverage work — a scripted fake ACP bin fixture (reads JSON-RPC frames on stdin, emits canned responses and session updates, writes synthetic session JSONL under `DSH_SNAPSHOT_SESSIONS_ROOT`) driving `harness.ts` through every step op, expect-error branch, child-harvest ordering, and teardown path, and `suite.spec.ts` registering synthetic replay- and record-mode suites against temp fixture dirs (record mode is keyless here: the live API sits behind the bin, and the fake bin needs none); (3) `permissionAnswers` with its unit coverage. The sandbox branch then merges master down and adds its own suite: scenario table, own pin scenario, own overlay, fixtures recorded via `test:snapshot:record`.
-
-## Alternatives considered
-
-- **Copy the modules into each example** — the fork this RFC exists to prevent: the record/guard logic is exactly the code that must stay byte-identical across suites, and examples are outside the coverage gate, so each copy is also unmeasured.
-- **A shared module directory under `examples/`** — keeps the code outside the coverage gate and forces relative imports across example boundaries, against the package-name import convention; `examples/` leaves stay thin by design.
-- **A `/testing` subpath export of `dsh-acp-agent`** — couples test infrastructure into a product package's surface and dependency set; `packages/support/` exists precisely for real-but-lower-compatibility dev/test packages, with `dsh-llm-replay` as the precedent this proposal completes.
-- **Export raw test-body functions instead of a suite factory** — each example would re-own the `describe`/`it` skeleton (~80 lines of registration boilerplate per suite) for no flexibility gain; the factory keeps consumers to a scenario table plus one call, and the pure guard functions preserve unit-testability inside the factory design.
-- **An injectable ACP `Client` factory instead of declarative `permissionAnswers`** — maximally flexible, but it leaks SDK client construction to every consumer and reopens per-example drift in exactly the layer being unified; a declarative queue keeps `input.json` the single scripting surface and stays golden-normalizable.
-- **Generalize beyond ACP (a transport-agnostic snapshot harness)** — no second transport exists; the harness is ACP-shaped end to end (SDK client, JSON-RPC frames, `session/update` waiters), and a speculative abstraction would be a seam split ahead of any consumer.
-
-## Acceptance criteria
-
-- After the pure-move commit, `pnpm run test:snapshot` is green with zero byte changes under `examples/acp-agent/tests/snapshots/` — the machine proof that extraction changed no behavior.
-- `pnpm run test:coverage` holds the new package's `src/` at per-file 100% with keyless unit specs; any `v8 ignore` carries its reason.
-- `examples/acp-agent/tests/acp.snapshot.ts` contains no golden/compare/guard logic — only the scenario table, the agent paths, and the factory call.
-- A harness unit test drives a `permissionAnswers` script through kind→`optionId` mapping and the exhaustion fallback, demonstrating the tier can express an approval round-trip before the sandbox suite needs it.
-- `doc-sync`, `hygiene`, and `verify-module-graph` pass with the new package wired in.
-
-## Risks
-
-- **Per-file 100% on `suite.ts`** is the tightest constraint: `toMatchFileSnapshot` update semantics differ under CI, and factory-registered tests must be driven by real vitest collection. The pure-guard-function split plus synthetic-suite registration is the mitigation; a justified `v8 ignore` is the last resort, not the plan.
-- **`vitest` becomes a `src` dependency** of a workspace package (the factory imports `describe`/`it`/`expect`), so importing `suite.ts` outside a vitest run throws — acceptable for a support-tier package and stated in its README, but it is a shape no other package has.
-- **Fake-bin drift**: harness unit tests exercise plumbing against a scripted bin, not the real one. The real bin path stays exercised on every `test:snapshot` run, so drift surfaces there; the fake bin only owns branches the live suite cannot deterministically reach.
-- **Per-suite pins duplicate header bulk**: each new suite commits one full ~8 KB header fixture. Accepted — a suite whose composition equals another's is the degenerate case the uniformity guard would surface, and one pinned line per genuinely distinct composition is the pinned-header design applied at its natural scope.
-- The extraction touches the gating snapshot suite itself; a subtle behavior change would surface as golden churn. The zero-byte-diff acceptance criterion is the guard.