feat(surface,sdk): f.slack helper namespace (#299)

[kjgbot]

Closes #299.

Summary

First helper namespace — f.slack.post(channel, text) / f.slack.reply(event, text) — establishing the pattern for the other 50 providers from @relayfile/relay-helpers.

Design decisions

• Mock + mount path only. RELAYFLOWS_SLACK_MOCK=1 writes intended payload to a file rather than hitting Slack — for CI. Direct-token direct transport is deferred: SLACK_BOT_TOKEN idempotency depends on Slack-server ts dedup which mount-writeback already handles correctly.
• Kernel primitive stays agent+effect. No new StepKind. f.slack.post lowers to an effect step on the existing agent primitive.
• SIGKILL replay semantics. Existing kernel records step.completed for crashed attempts too, so a SIGKILL sweep produces one completionReason:crashed + exactly one completionReason:success. Test asserts exactly one successful completion + pins the crash record explicitly.

Written by codex agent spec-B-f-slack-v4 on finn-mini; head at 1f044e3.

Test plan

• linux-x64-artifact green
• packed-consumer green

🤖 Generated with Claude Code

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Note

Medium Risk
Adds external side effects (Slack writeback), credential/mount gating, and crash-recovery semantics on the effect path; kernel protocol is unchanged but misconfiguration or resume without the data dir could surprise operators.

Overview
Introduces f.slack on the authored TypeScript surface (post, dm, reply, react) as journal-backed Steps, establishing the first provider-helper pattern for future relay-helpers integrations.

Surface adds SlackHelper types, flowRunWritebackIdempotency(runId, stepId), and optional flow header tools: { slack: true } for static preflight without running the body.

SDK wires each awaited Slack call through a dedicated helper run that reuses the existing agent + performEffect on /slack path (no new kernel verb). Writes go through @relayfile/relay-helpers with a relayfile slack/ mount writeback transport; RELAYFLOWS_SLACK_MOCK=1 records payloads under the data dir. Preflight refuses missing credentials (helper_slack.credential_missing) or bot-token-only setups (helper_slack.mount_required). flows check on .ts flows imports the definition and runs helper checks without executing the body; flows resume can reattach Slack helper runs using persisted receipts in <data-dir>/helper-receipts/.

Adds @relayfile/adapter-core and @relayfile/relay-helpers dependencies, docs/SLACK-HELPER.md, and integration tests covering mock journaling, credential refusal, crash/replay idempotency, and mount writeback.

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[coderabbitai]

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[kjgbot]

maintainability lens — FAIL

Maintainability Review — PR #314 (Slack helper)

Blockers

B1. preflightHelpers gates a hard refusal on a stringified-body regex — packages/sdk/src/preflight.ts:497-499:

usesSlack = header.tools?.slack === true
  || /(?:\.\s*slack\b|\[\s*['"]slack['"]\s*\])/.test(Function.prototype.toString.call(body))

This produces refusal for any comment, string literal, or unrelated identifier containing .slack (e.g. const url = "https://api.slack.com", or a .slackKey property). A stranger cannot safely tune this regex — there is no test that pins the boundary, and no mention that Function.prototype.toString output is engine-defined. The contract "call means it might use Slack" is invisible.

B2. assertSlackCredentials synthesizes a fake definition to reuse preflightHelpers — packages/sdk/src/authored-slack-effect.ts:15-22. It passes { header: { tools: { slack: true } }, body(){} }, then keys the error code off "first diagnostic kind is mount_required, else credential_missing." This is an implicit contract: any change to preflightHelpers's diagnostic ordering silently changes production error codes. Extract an env-check that both callers share, rather than calling preflight for its side-diagnostic.

B3. resumeSlackEffect bails silently five times — authored-slack-effect.ts:41-49. Regex on runId, existsSync marker, steps.length !== 1, step.type !== 'agent', stream prefix, verb allow-list — each returns false without a log. A future maintainer investigating "why doesn't resume pick up my helper run?" has no signal. Either log the reject-reason or fold these into one named guard with a comment tying them to the journal envelope contract.

Concerns

C1. authored-flow-executor.ts:135-137's special-case for tools.slack requires every future supported helper to remember to extend this filter (some(key => key !== 'slack')). Prefer an allow-list constant so the invariant is one grep away.

C2. runSlackEffect falls back to dirname(journal.socketPath) for dataDir — authored-flow-executor.ts:203-205. Silent surprise: receipts land next to the socket if a caller forgets dataDir. Fail closed or drop the fallback.

C3. checkHelperBody name overstates what it does — cli/check-helper-body.ts. It imports the module (running top-level code) and then applies the header check + a regex; it does not analyze the body. The doc comment ("never executes arbitrary authored body code") is also load-bearing yet weaker than it sounds — module import runs top-level effects.

C4. SLACK-HELPER.md:32-34 — "flowRunWritebackIdempotency(runId, stepId) always returns runId:stepId. The process-tick stamper cannot replace this token." This asserts an invariant the code does not itself enforce (no test pins the return, and no runtime guard prevents another stamper). Either add a pinned test or delete the claim.

C5. JournalClient.socketPath widened from private readonly to readonly — journal-client.ts:68. Silent public-API expansion driven by one caller (driveSlackEffect). Prefer a getSocketPath() or pass the path through explicitly, keeping the field private.

Notes

• driveSlackEffect opens a second JournalClient with no comment on why the primary one cannot serve — future reader will not know if this is essential.
• direct-run.ts:118-119 computes kind via a nested ternary inside object-literal construction; extract to a named local.
• authored-slack-effect.ts at 121 lines mixes preflight, spec compile, resume detection, dispatch driving, and effect completion — will grow as more verbs land. Split before adding the next provider.

REVIEW_FAILED

[kjgbot]

history lens — FAIL

Blocker — settled decision #6: the implementation edits its own acceptance gate. In scripts/surface-package-gate.sh:116–117,136–139, this PR adds Slack assertions directly to the packed-consumer gate. .github/workflows/surface-package.yml:30–43 executes that script from the candidate head. RFC-0001 §6 decision #6 prohibits agents editing gates that judge their work; it does not limit the prohibition to weakened assertions.

The relevant history is explicit: ops/DRIVE-LOG.md:1190–1218 records replacing branch-owned verification with an immutable main-owned gate, and 6273–6298 explains why candidate-controlled verification inputs violate that boundary. These additions strengthen coverage, but still modify the judging gate. Move the new coverage into ordinary package tests while leaving the gate unchanged, or arrange independently owned gate changes and validation.

Command: sed -n '30,32p;42,43p' .github/workflows/surface-package.yml

Captured output:

      - uses: actions/checkout@v4
        with:
          ref: ${{ github.event.pull_request.head.sha || github.sha }}
      - name: Test source, regressions, and packed consumers
        run: bash scripts/surface-package-gate.sh

Concerns — nonblocking. docs/SLACK-HELPER.md:53–57 explicitly limits recovery to individual helper runs and defers whole-body durability and postfix gates. Those disclosed limitations do not justify rejection under this lens. The PR summary’s reply(event, text) example also needs correction to match packages/surface/src/slack.ts:13, which accepts channel, thread timestamp, and text; this is PR-body wording, not a false commit-message claim.

Notes. The actual commit messages make no test-pass or mutation-verification claims. packages/sdk/src/authored-slack-effect.ts:31–35 retains the existing agent primitive, and packages/sdk/src/slack-writeback.ts:56–64 routes production effects through mount writeback, consistent with decisions #1 and #13. Tests were not executed for this static history review. The RFC-referenced predecessor charter was unavailable locally.

REVIEW_FAILED

[kjgbot]

structure lens — MISSING

[kjgbot]

🎯 review-swarm: FAILED (M:fail H:fail S:missing)

Lens transcripts posted as sibling comments above.