Verify

Turn an approved SpecScore Feature plus its Verifies: commit trailers into a per-AC verdict report. Close the SpecStudio pipeline's verify slot so recap has an honest gate to consume.

Hard Gate

The only skill invoked after specstudio:verify is specstudio:recap (or — while recap is unshipped — a hand-back to the user with the report path and a recommendation to review verdicts manually). </HARD-GATE>

When to Use

• An approved Feature at spec/features/<feature-slug>/README.md exists in git HEAD and the user wants a per-AC verdict on the work already committed.
• specstudio:implement has just transitioned via its transition-to-verify REQ and the consolidated batch has been committed.
• The user wants to re-verify a Feature after additional Verifies:-trailed commits have landed.

Refuse and redirect when:

• The Feature's **Status:** is Draft or In Review → print the current Status and recommend specstudio:specify to re-approve. Write no report. Exit non-zero. (AC: refuses-draft-feature)
• The Feature exists only in the working tree (uncommitted) → instruct the user to commit the Feature first. Write no report. Exit non-zero. (AC: refuses-uncommitted-feature)
• The user asks the skill to bypass publication policy, commit unrelated paths, or push without branch-policy approval → refuse.
• The user asks the skill to invoke ship, review, or any non-recap skill → refuse; the only permitted downstream transition is specstudio:recap.

Pre-Flight

1. Resolve input. The skill MUST accept exactly one positional argument — the Feature slug — and resolve it to spec/features/<feature-slug>/README.md.
2. Status guard. Read the Feature's body-metadata **Status:** line. Refuse if it is outside {Approved, Implementing, Stable}. On refusal, print the current Status, recommend specstudio:specify to re-approve, write no report, and exit non-zero.
3. HEAD-existence guard. Run git cat-file -e HEAD:spec/features/<feature-slug>/README.md. On non-zero exit, refuse with an instruction to commit the Feature first, write no report, and exit non-zero. This mirrors implement's pre-flight discipline — the Verifies: trailer convention requires the Feature to exist in git history.
4. Resolve HEAD SHA. Capture git rev-parse --short HEAD once. This SHA is the <sha> in the report path and the revision in the YAML summary and the event payload.

Checklist

Create a task for each and complete in order:

1. Pre-flight (steps above). Refusals exit immediately; do not proceed.
2. Parse the Feature. Delegate to the specscore CLI's Feature parser. Surface the ordered list of AC IDs in the form <feature-slug>#ac:<ac-slug> paired with each AC's full Given / When / Then text. Parse failures stop the skill with the CLI's lint-rule citation surfaced verbatim to the user.

3. Collect commits per AC. For each AC ID in Feature order, run:

   git log --extended-regexp --grep='^Verifies:.*<feature-slug>#ac:<ac-slug>' --format='%H%n%s%n%b%x00'

   Collect the matching commit SHAs in chronological (oldest-first) order paired with their commit messages (subject + body). Do NOT pre-fetch commit diffs — the subagent fetches diffs on demand. An AC with zero matching commits is recorded as unmapped and skipped for subagent dispatch.

4. Dispatch verifier subagents serially. For each mapped AC (commit count ≥ 1) in Feature AC order, dispatch one verifier subagent via the Agent tool with subagent_type: general-purpose. Construct the prompt per ## Verifier Subagent Contract below. Wait for the subagent to return a parseable verdict before dispatching the next AC's subagent. At no point during the run MUST more than one verifier subagent be concurrently in flight.
5. Parse the verdict. Validate per ## Verifier Subagent Contract. On a malformed first response, re-dispatch the same subagent exactly once with a corrective prompt that quotes the failure (verdict outside {pass, fail, error}, missing justification, or justification exceeding 400 characters) and reiterates the verdict contract. On a malformed second response, record the AC's verdict as error and MUST NOT call the subagent a third time.
6. Tally counts. Compute passed_count, failed_count, unmapped_count, errored_count over the full AC list. Each is a non-negative integer; their sum equals the Feature's total AC count.
7. Write the report. Create spec/features/<feature-slug>/_verify/ if absent. Write the report file to spec/features/<feature-slug>/_verify/<sha>.md per ## Report Format below.
8. Write or update the _verify/README.md index. Per ## Report Format → Index README below. If absent, create it with one row in ## Contents. If present, append one row for the current run, preserving prior rows. Without this step the project's readme-exists lint rule will fail on the newly created _verify/ directory.
9. Publication checkpoint. Add spec/features/<feature-slug>/_verify/<sha>.md and spec/features/<feature-slug>/_verify/README.md to the manifest. Apply publication-policy.md for verify.completed, staging only manifest paths and committing/pushing only when policy and safety allow.
10. Emit verify.completed. Per ## Event Emission below, including publication_result. Exactly once per successful run.
11. Transition. Per ## Promotion Boundary below. Only specstudio:recap (or hand-back when recap is unshipped).
12. Determine exit code. Per ## Exit Semantics below. Non-zero iff failed_count + errored_count > 0. Otherwise zero.
13. Throughout — watch for sidekick ideas (e.g., a flaky subagent shape, a deferred AC-coverage gap surfacing during verification). When an out-of-scope improvement surfaces, invoke specstudio:sidekick with a one-liner, acknowledge in one line, and return to the current checklist step immediately. Do not derail.

Verifier Subagent Contract

Each verifier subagent is dispatched with an isolated prompt — it MUST NOT inherit the parent session's context. Construct the prompt freshly per AC.

Prompt shape (four required parts, in this order)

1. AC identification and full text. The AC ID (<feature-slug>#ac:<ac-slug>) followed by its complete Given / When / Then text quoted verbatim from the source Feature.

2. Matching commits. The ordered list of commit SHAs (chronological, oldest-first) paired with each commit's full message (subject + body). Format:

   ## Matching commits
   
   - <sha-1>
     <commit message subject + body>
   - <sha-2>
     <commit message subject + body>

   The orchestrator MUST NOT include pre-fetched commit diffs in the prompt. The subagent fetches diffs and reads source files on demand via its own Bash tool.

3. Verdict contract (verbatim). Quote the following block into the prompt verbatim, so the subagent knows the required output shape:

   Return exactly one verdict from the set: {pass, fail, error}.
   
   Required output shape:
   
     verdict: <pass | fail | error>
     justification: <one-line snippet, MAXIMUM 400 characters>
     evidence:
       - <file path, commit SHA, or reference>
       - ...
   
   - `pass`   = the matching commits satisfy the AC's `Then` clause.
   - `fail`   = the matching commits do NOT satisfy the AC's `Then` clause.
   - `error`  = you cannot reach a verdict (e.g., a commit is unreachable, a referenced
                file is missing, the AC text is ambiguous in a way that no diff can resolve).
   
   The value `unmapped` is produced only by the orchestrator for ACs with zero matching
   commits and MUST NOT appear in your response.
   
   Malformed responses (verdict outside the allowed set, missing justification, or
   justification exceeding 400 characters) will be re-dispatched exactly once with a
   corrective prompt; a second malformed response is recorded as `error`.

4. Fetch-on-demand instruction. An explicit instruction that the subagent fetches commit diffs and reads source files on its own via Bash. Suggested commands to mention:

   git show <sha>
   git show <sha> -- <path>
   git show <sha> --stat
   cat <path>

   Include the guidance: "Read at the depth required to reach a verdict; do not enumerate every file in every commit if the verdict is obvious from one diff."

Out of scope for the prompt

• No pre-fetched diffs. The orchestrator MUST NOT inline git show output into the prompt. Diff fetching is the subagent's responsibility.
• No _tests/ reference. The semantic role of _tests/<ac-slug>.md Markdown scenarios is deliberately deferred to a future Idea (captured as a sidekick seed during the Feature's specify session). The prompt MUST NOT instruct the subagent to read _tests/ files. The subagent MAY discover them via Bash if it chooses, but no instruction directs it there.
• No unmapped verdict. unmapped is orchestrator-produced. The allowed-verdict set named in the prompt is {pass, fail, error} ONLY.

Verdict parsing

A well-formed response contains:

• A verdict: line whose value is exactly one of pass, fail, error.
• A justification: line whose value is non-empty and at most 400 characters.
• An evidence: list with zero or more entries (file paths, commit SHAs, or other references).

Anything outside this shape is malformed. Apply the retry-once-then-error semantics per checklist step 5.

Report Format

Path

spec/features/<feature-slug>/_verify/<sha>.md

<sha> is the abbreviated git SHA of HEAD at run time (git rev-parse --short HEAD). Create the _verify/ directory if absent.

YAML summary block (grep target)

The report MUST open with a fenced YAML block (delimited by ```yaml and ```) listing every AC in Feature AC order. This block is the grep target downstream skills (recap, eventually ship) consume.

feature: <feature-slug>
revision: <sha>
verdicts:
  - ac: <feature-slug>#ac:<ac-slug-1>
    verdict: pass
    justification: "<one-line snippet, ≤400 chars>"
  - ac: <feature-slug>#ac:<ac-slug-2>
    verdict: unmapped
    justification: "no commits reference this AC"
  - ac: <feature-slug>#ac:<ac-slug-3>
    verdict: fail
    justification: "<one-line snippet>"
  - ac: <feature-slug>#ac:<ac-slug-4>
    verdict: error
    justification: "<one-line snippet>"

Every AC from the source Feature MUST appear exactly once, in Feature AC order. The four allowed verdict values are pass, fail, error, unmapped.

Body (per-AC sections)

After the YAML block, the report MUST contain one ## AC: <ac-slug> section per AC, in Feature AC order. Each section contains:

## AC: <ac-slug>

**Verdict:** <pass | fail | error | unmapped>

**Justification:** <full justification text — same as the YAML one-liner if short, or
expanded for human readability if the subagent supplied a richer rationale>

**Commits:**
- <sha-1> — <commit subject>
- <sha-2> — <commit subject>

(Or: "No commits reference this AC." for `unmapped` ACs.)

**Evidence:**
- <file path, commit SHA, or other reference>
- ...

The YAML block is the machine-readable surface; the body is the human-readable surface.

Index README

The skill MUST create spec/features/<feature-slug>/_verify/README.md if absent and MUST append a row for the current run to its ## Contents table on every run. The README is the directory's index — without it, the project's readme-exists lint rule fails on the newly created _verify/ directory.

Shape (when creating from absent):

# Verify Reports — <feature-slug>

Per-run verify reports produced by `specstudio:verify`. Each report is named `<sha>.md` where `<sha>` is the abbreviated git SHA of `HEAD` at run time.

## Contents

| Report | Run revision | Verdict summary |
|---|---|---|
| [<sha>.md](<sha>.md) | <sha> | <one-line verdict summary, e.g., "5 passed, 0 failed, 0 unmapped, 0 errored" or "19 unmapped, 0 passed/failed/errored"> |

## Open Questions

None at this time.

---
*This document follows the https://specscore.md/index-specification*

Append rule (when README already exists):

Locate the ## Contents table. Insert a new row at the bottom of the table (newest-last). Preserve every prior row in its existing order — never reorder, never delete. The new row's Report cell is a Markdown link [<sha>.md](<sha>.md); the Run revision cell is the abbreviated SHA; the Verdict summary cell is a one-line tally derived from the four flat counts.

If the table is missing entirely (e.g., README was hand-edited), the skill MUST refuse to write the row, surface the missing-table error to the user, and recommend manual repair before re-running.

Publication discipline

After writing the report and the index README, the skill MUST add both to the checkpoint manifest and apply publication-policy.md for verify.completed. If the allowed actions include stage, stage only those manifest paths. If they include commit or push, run the shared unrelated-index and branch-safety checks first. The disclosure must name the resolved policy, executed actions, skipped actions, and manifest paths.

No-commits edge case

When a Feature has zero Verifies: trailers in the entire branch history (e.g., a Feature that was specified but not yet implemented), the skill MUST still:

• Write the report at the canonical path.
• Mark every AC unmapped in both the YAML block and the body sections.
• Apply publication policy to the report and index manifest.
• Emit verify.completed with unmapped_count equal to the Feature's total AC count, the other three counts equal to zero, and publication_result.
• Exit zero.

The report itself communicates that nothing has been implemented yet; the absence of a report is not the right signal.

Exit Semantics

The skill MUST exit non-zero if and only if failed_count + errored_count > 0. Equivalently:

unmapped is informational at the verify layer. ship is the eventual gate that escalates unmapped to blocking; verify does not.

A pre-flight refusal (Draft Feature, uncommitted Feature) exits non-zero without writing a report — those refusals are distinct from the verdict-tally exit code above.

Event Emission

After the report is written and publication policy has been applied (and only on a successful run — pre-flight refusals do NOT emit), the skill MUST emit exactly one verify.completed event via the convention in events.md. Use specscore event emit <event.yaml> when the CLI is available; fall back to appending the event JSONL line to .specscore/events.jsonl.

Payload shape (flat counts — NOT a nested verdict_counts object):

event: verify.completed
version: 1
uuid: <generated>
timestamp: <ISO-8601>
actor:
  kind: skill
  id: skill:specstudio:verify
artifact:
  type: feature
  id: <feature-slug>
  path: spec/features/<feature-slug>/README.md
  revision: <sha>
payload:
  feature_slug: <feature-slug>
  revision: <sha>
  report_path: spec/features/<feature-slug>/_verify/<sha>.md
  passed_count: <int ≥ 0>
  failed_count: <int ≥ 0>
  unmapped_count: <int ≥ 0>
  errored_count: <int ≥ 0>
publication_result:
  resolved_actions: [<stage | commit | push>, ...]
  executed_actions: [<stage | commit | push>, ...]
  skipped_actions: [{action: <stage | commit | push>, reason: <string>}]
  commit_sha: <git SHA> | null
  push_target: <remote>/<branch> | null

Invariants:

• All four count fields are non-negative integers.
• passed_count + failed_count + unmapped_count + errored_count equals the Feature's total AC count.
• The payload MUST NOT include per-AC verdict details. Consumers read those from the report file at report_path.
• The event MUST be emitted exactly once per successful run.
• Additional payload fields MAY be added in the future without breaking this contract; the four count fields plus feature_slug, revision, and report_path are the minimum.

Promotion Boundary

The next skill is specstudio:recap, and only specstudio:recap.

Transition

After the report is written, publication policy is applied, and verify.completed is emitted:

• If specstudio:recap is shipped: offer to transition the user to specstudio:recap, passing the report_path as input.

• If specstudio:recap is unshipped: hand back to the user with the report path and a recommendation to review verdicts manually:

  "Verify complete. Report written at spec/features/<feature-slug>/_verify/<sha>.md and publication policy applied. The specstudio:recap skill is not yet shipped — review the YAML summary block in the report for per-AC verdicts."

The skill MUST NOT invoke ideate, specify, plan, implement, review, ship, writing-plans, frontend-design, or mcp-builder on transition. The hard gate above pins this; the transition step honors it.

Tone

The skill MUST NOT yes-machine soft verdicts. When a subagent returns pass on a commit set that obviously does not satisfy the AC, the skill MUST trust the subagent's verdict for THIS run (the orchestrator does not re-judge), but MUST surface the report honestly — the YAML block and the body section carry the verdict as returned. Re-judgment is recap's job, not verify's.

When the skill detects a pre-flight refusal (Draft Feature, uncommitted Feature), it MUST say so with the specific cited cause (current Status value, missing-from-HEAD path) and propose the alternative (specstudio:specify, git commit). Honest specificity, not performative agreement.

When the subagent returns malformed responses twice in a row, the skill records error and moves on — it MUST NOT loop infinitely.

Verification

• Pre-flight checks passed: input slug resolves; Feature **Status:** ∈ {Approved, Implementing, Stable}; Feature exists at git HEAD
• Feature parsed cleanly via specscore CLI; ordered AC list captured
• For each AC: git log --grep='^Verifies:.*<feature-slug>#ac:<ac-slug>' ran; matched SHAs + commit messages collected; NO diffs pre-fetched
• Subagent dispatch was serial: at no point were two verifier subagents concurrently in flight
• Each per-AC subagent prompt contained: full G/W/T text, commit SHAs + messages, verbatim verdict contract, and the fetch-on-demand Bash instruction; no pre-fetched diffs
• Malformed verdicts were retried exactly once; second-time malformed verdicts were recorded as error
• Report written at spec/features/<feature-slug>/_verify/<sha>.md with the fenced YAML block first, then ## AC: body sections
• Every AC appears in the YAML block in Feature AC order with one of {pass, fail, error, unmapped}
• _verify/README.md index created (if absent) or row-appended (if present); table preserves prior rows in their existing order
• Both report and _verify/README.md added to the checkpoint manifest; publication policy applied with disclosure
• specscore spec lint exits zero after the run (no readme-exists failure on the _verify/ directory)
• verify.completed event emitted exactly once; payload counts sum to the Feature's total AC count; no per-AC details in the payload; publication_result is present
• Exit code is non-zero iff failed_count + errored_count > 0; otherwise zero
• No-commits edge case (every AC unmapped) still produced a complete report, applied publication policy, emitted the event, and exited zero
• On transition: only specstudio:recap invoked (or hand-back when unshipped); no other skill touched

Red Flags

• Pre-fetching commit diffs into the subagent prompt (the subagent fetches diffs on demand; the orchestrator does not)
• Naming unmapped in the subagent's allowed-verdict set (it is orchestrator-produced; the prompt names {pass, fail, error} only)
• Instructing the subagent to read _tests/<ac-slug>.md files (deferred to a future Idea; not in MVP)
• Dispatching two verifier subagents concurrently (serial only; parallelism is explicitly deferred per the source Idea's ## Not Doing)
• Looping the malformed-verdict retry more than once (one retry; second malformed → error; never a third call)
• Allowing a justification longer than 400 characters to pass the verdict-contract check
• Hard-coding stage-only report handoff instead of resolving publication policy for verify.completed
• Committing unrelated staged paths or pushing without branch-policy approval
• Writing the report to docs/ or to a path other than spec/features/<feature-slug>/_verify/<sha>.md
• Treating unmapped as a non-zero-exit signal (it is informational at the verify layer; ship escalates it later)
• Skipping the verify.completed event because "no failures" — the event fires on every successful run regardless of verdict outcomes
• Emitting verify.completed with per-AC verdict details in the payload (per-AC data lives in the report file; the event payload carries flat counts only)
• Nesting the four counts under a verdict_counts: key (the contract is flat: passed_count, failed_count, unmapped_count, errored_count)
• Invoking any skill other than specstudio:recap on transition (no review, no ship, no writing-plans, no frontend-design, no mcp-builder)
• Refusing to write a report when no commits match (the no-commits edge case still produces a complete unmapped-only report)
• Writing the per-run report but forgetting _verify/README.md (the readme-exists lint rule will fail on the newly created _verify/ directory)
• Reordering or deleting prior rows in _verify/README.md's ## Contents table (the skill only appends; prior runs' rows are preserved verbatim)

References

• Feature: Verify Skill — the SpecScore Feature this skill implements.
• Feature: Implement Skill — the upstream Feature whose Verifies: commit-message trailer this skill consumes.
• Plan: Verify Skill MVP — the seven-task plan this skill realizes.
• philosophy.md — shared tenets.
• publication-policy.md — checkpoint resolution, manifest safety, first-run preference prompt, and publication disclosure.
• events.md — event-envelope contract and emission transport for verify.completed.
• sidekick-capture.md — sidekick-idea handling during the skill's flow.
• PRINCIPLES.md — repo-level principles (user-attention economy, batched questions, parallel work while user is idle).