recap-doc

/recap-doc — Recap Document Generator

Trigger

• Keywords: recap-doc, generate recap, 產出導覽文件, walkthrough doc, 本輪導覽

When NOT to Use

Scenario	Alternative
Interactive Q&A over an existing recap	/recap-ask
Full flow (detect + doc + Q&A)	/post-dev-recap wrapper
Technical share-out for other developers	/tech-brief
Single function explanation	/codex-explain
First-principles reasoning of an existing doc	/fp-brief

Command Signature

/recap-doc --scope <json-path-or-inline> [--focus <str>] [--depth brief|normal|deep] [--output <path>]

Flag	Default	Description
--scope	required	Path to ScopeReport JSON or inline JSON string (from scripts/detect-scope.js)
--focus	""	Natural-language keyword to bias section emphasis (e.g. "auth middleware")
--depth	normal	Output depth — affects top-N, section verbosity, and optional sections
--output	auto	Output file path (see Save Behavior)

Workflow

sequenceDiagram
    participant U as Caller (user or /post-dev-recap)
    participant D as /recap-doc
    participant S as scripts/detect-scope.js
    participant T as tech-brief-style collection
    participant CE as /codex-explain (Skill)
    participant SR as scripts/security-redact.js
    participant F as Output file

    U->>D: /recap-doc --scope <json> [--depth]
    D->>D: Phase 1: Load & validate ScopeReport
    D->>T: Phase 2: Collect git evidence for scope.files (reuse tech-brief Stage 2)
    D->>D: Phase 3: Cross-reference tech-spec (if feature_context.has_tech_spec)
    D->>CE: Phase 4a: Explain top-N changed files
    D->>D: Phase 4b: Synthesize sections + Blind Spots (Must) + Anticipated Questions
    D->>SR: Phase 5a: Scan output for high/medium-confidence secrets
    SR-->>D: Redacted or AbortError
    D->>F: Phase 5b: Write briefing-recap-<date>.md
    D-->>U: Emit output path + summary

Phase 1 — Scope Load

1. Parse --scope argument: accept file path, - for stdin, or inline JSON (detected by leading {).
2. Validate ScopeReport v1 required fields: version === 1, source, files[], feature_context, fallback_trace.
3. If source === null or files.length === 0 → exit non-zero with message directing user to rerun scripts/detect-scope.js.

Phase 2 — Evidence Collection (reuse tech-brief Stage 2)

See references/source-guide.md for the full strategy. Summary:

• Run git log --oneline -20 -- <path> per scope file (capped at top-N by depth)
• Run git diff --stat <base-ref>..HEAD -- <path> for magnitude
• Read top-N changed files (100 lines each, source files only; exclude docs/test)

Top-N by depth: brief=5, normal=10, deep=15.

Phase 3 — Spec Cross-reference

When scope.feature_context.has_tech_spec === true:

1. Read <docs_path>/2-tech-spec.md
2. Extract section headings + Work Breakdown items
3. Prepare drift-check input: list each tech-spec work item + implementation evidence (changed files overlap)

Phase 4 — AI Synthesis

See references/prompt-template.md for the full prompt. Key behaviors:

1. Per-file explanations (Phase 4a): for each top-N file, invoke /codex-explain (Skill tool call) with --lines scoped to changed hunks. Reuse, not reimplement — this satisfies NFR-5.
2. Section synthesis (Phase 4b): compose §1 Overview through §7 Evidence using the output template (see references/output-template.md).
3. Blind Spots (FR-9, Must — any depth): even if no obvious blind spots are found, emit the §5 heading with the fallback wording 「本輪未偵測到明顯盲點」+ 推論依據.
4. Anticipated Questions (FR-11): present ≥ 3 questions at normal/deep; omit at brief.

Phase 5 — Redaction + Write

1. Load scripts/security-redact.js and invoke redact(text) on the complete markdown output.
2. If AbortError is thrown → do not write; emit stderr with fingerprint and exit non-zero.
3. If redacted successfully → validate output path via fs.realpathSync on the first existing ancestor (must resolve inside repo root or <tmp>; no .. / external symlink).
4. Write file with trailing newline.

Depth Levels

See the full matrix in references/output-template.md. Summary:

Level	Top-N	§5 Blind Spots	§6 Anticipated Q	Code snippets
brief	5	Top-3 only	Omitted	No
normal	10	Full list	≥ 3	No
deep	15	Full list	≥ 3	Inline

Save Behavior

Recap output is ephemeral by default — written to the OS temp directory so the user's project tree stays clean. Callers that want the recap checked in must opt in with --output.

Condition	Output Path
Default (no --output)	<tmp>/sd0x-dev-flow-recap/briefing-recap-<YYYY-MM-DD>.md
--output <path> provided	Explicit path; the canonical (realpath-resolved) target must lie inside either the repo root or <tmp>. Paths that escape both roots are rejected (see ## Path Security).

Where <tmp> resolves in this order:

1. $TMPDIR environment variable (honoured on macOS by default).
2. Node's os.tmpdir() (portable fallback — in code this is require('os').tmpdir()).
3. /tmp as the final POSIX fallback.

The directory <tmp>/sd0x-dev-flow-recap/ is created if missing. If the target file already exists the same day, append a numeric suffix: briefing-recap-2026-04-17-r2.md.

Permanent recap: when the user wants the recap stored with the feature docs (e.g. shareable post-mortem), invoke with --output docs/features/<key>/briefing-recap-<YYYY-MM-DD>.md explicitly.

Path Security

Rule	Implementation
Default-dir boundary	Default path is always under <tmp>/sd0x-dev-flow-recap/ (<tmp> resolved via $TMPDIR → os.tmpdir() → /tmp, see ## Save Behavior); the skill never writes under the repo without an explicit --output
Explicit-path allowlist	--output <path>: accept any absolute or repo-relative path whose canonical (realpath-resolved) target lies inside the repo root or <tmp>; reject .. segments that escape the resolved parent and external symlinks whose target lies outside both roots
Symlink check	Resolve the output path with fs.realpathSync on the first existing ancestor; reject if the resolved ancestor is neither inside the repo root (git rev-parse --show-toplevel) nor inside <tmp>
Secret redaction	scripts/security-redact.js — abort on high-confidence, mask medium
Input trust	ScopeReport JSON paths are validated before any fs read

Performance

Target: NFR-2 — /recap-doc output generation ≤ 30s (excluding external LLM latency, measured from scope-load start to file-write complete). The Phase 4a per-file explanations should be dispatched in parallel batches to stay within budget.

Output Structure

See references/output-template.md for the canonical markdown template. High-level structure:

# Recap: <feature-key or "session">
> **Scope source**: ...
> **Detected at**: ...
> **Focus**: ...
> **Confidence**: ...

## 1. Overview
## 2. Changed Files (table with file:line references)
## 3. Design Decisions
## 4. Spec vs Implementation Drift    (if has_tech_spec)
## 5. Blind Spots                     (FR-9 Must — any depth)
## 6. Anticipated Questions           (normal/deep only)
## 7. Evidence                         (commit SHAs, file:line index)

Verification

• ScopeReport v1 validated (version + required fields) before any synthesis
• Top-N files aligned with depth (brief=5, normal=10, deep=15)
• §5 Blind Spots heading present regardless of depth; fallback wording when no items
• §6 Anticipated Questions ≥ 3 at normal/deep; omitted at brief
• /codex-explain invoked per top-N file (NFR-5 reuse — not reimplemented)
• security-redact.js invoked before write (NFR-7)
• Output path resolves (via fs.realpathSync) inside repo root or <tmp>; no ..; no external symlink
• Total pipeline ≤ 30s from scope-load to write (NFR-2)

References

• references/output-template.md — Recap doc structure + depth matrix
• references/source-guide.md — Phase 2 evidence collection (reuse tech-brief pattern)
• references/prompt-template.md — LLM synthesis prompt (obeys @rules/codex-invocation.md)
• @skills/tech-brief/references/source-guide.md — upstream pattern (read-only reference)
• @skills/codex-explain/SKILL.md — Phase 4a reuse target
• scripts/detect-scope.js — ScopeReport v1 producer (T1)
• scripts/security-redact.js — Pre-write redaction (T1)
• scripts/config/doc-taxonomy.json L94-99 — briefing- ancillary pattern

Examples

Input: /recap-doc --scope /tmp/scope.json --depth normal
Action: Load scope → collect git evidence for top-10 files → /codex-explain per file → synthesize sections including Blind Spots + 3+ Anticipated Questions → security-redact → write to <tmp>/sd0x-dev-flow-recap/briefing-recap-2026-04-17.md (ephemeral default; user opts in to commit via --output)

Input: /recap-doc --scope '{"version":1,"source":"uncommitted",...}' --focus "auth" --depth brief
Action: Parse inline JSON → filter to auth-related files → top-5 only → §5 Blind Spots top-3 only → omit §6 → write to <tmp>/sd0x-dev-flow-recap/briefing-recap-<YYYY-MM-DD>.md

Input: /recap-doc --scope scope.json --depth deep --output docs/features/<key>/briefing-recap-2026-04-17.md
Action: Load scope → top-15 with inline code snippets → full §5/§6 → redact → realpath-resolve target (must be inside repo root OR <tmp>) → write. Paths that escape both roots are rejected.