/stitch — Cross-repo stitch layer

Generate a cross-repo binding artifact (STITCH.md) for a product group (backend + one or more frontends). Tables only, not narrative. Drift detection uses CODEMAP endpoint sections by default with explicit opt-in fallback to grep.

Step 0: Load config

Read ~/.claude/aria-knowledge.local.md. Parse YAML frontmatter projects_groups (multi-line YAML block — see CONFIG.md "Skill-only fields" for canonical schema, including the optional stitch_path sub-field and custom-role conventions).

Look up <tag> in projects_list (get project_root) and projects_groups (get role → folder dict).

• If <tag> missing from projects_list: stop with "unknown project tag: <tag>".
• If <tag> in projects_list but missing from projects_groups and <project_root> has multiple distinct codebases that must stay in sync (separate repo-marker sub-dirs, OR one repo with a shared-contract source + multiple generated/typed clients — see scan below): trigger auto-propose bootstrap. The git-repo boundary is NOT the signal — a monorepo with a contract/ → ios/+android/+backend/ seam qualifies just as much as separate repos.
• If <tag> is a single undifferentiated codebase (no separate sub-dirs and no contract→multi-client seam): load <project_root>/CODEMAP.md only.

Auto-propose bootstrap (when projects_groups[<tag>] is missing but <project_root> contains multiple sync-bound codebases — separate repo dirs or a contract→clients seam):

1. Scan <project_root> one level deep for sub-directories with repo or contract markers:
   • openapi.{yaml,yml,json} / *.proto / schema.graphql (or a dir named contract/contracts/api-spec/proto) → contract (the shared source clients are generated from — its drift is what STITCH tracks)
   • manage.py + settings.py → backend (Django)
   • composer.json + artisan → backend (Laravel)
   • Gemfile with rails → backend (Rails)
   • package.json with express/fastify/nestjs → backend (Node)
   • pyproject.toml/requirements.txt with fastapi/pydantic → backend (FastAPI)
   • Package.swift / *.xcodeproj / an ios dir → ios (Swift/SwiftUI)
   • build.gradle{,.kts} with an android dir → android (Kotlin/Android)
   • next.config.* → web (Next.js)
   • app.json + expo in package.json → mobile (Expo)
   • package.json with react (no next/expo) → web (React SPA)
   • other package.json → prompt user for role name
2. Handle role conflicts: if two dirs inferred as same role, prompt user to assign distinct keys (web, web-admin, etc.).
3. Propose the group structure to user: sub-repo names, inferred roles, YAML block to insert. Show a preview diff of the change to ~/.claude/aria-knowledge.local.md.
4. On approval, edit the config file to add the projects_groups[<tag>] entry, preserving existing fields and YAML structure.
5. On decline, stop with "proceed after registering group manually".

Resolve each (role, folder) pair to absolute path: <project_root>/<folder>. For each absolute path, read CODEMAP.md if it exists. Read <project_root>/STITCH.md if it exists. Return resolved path map + warnings for any missing CODEMAPs.

For /stitch specifically: the group MUST have ≥2 distinct codebases bound by a shared contract — at least one contract/backend source role + at least one client role that must stay in sync with it. Whether they live in separate git repos or one monorepo is irrelevant — the load-bearing condition is "multiple codebases that drift apart," not "multiple repos." A monorepo's contract/ → ios/+android/+backend/ seam (the dual-native keystone — one OpenAPI/proto/GraphQL source feeding generated clients) is exactly the drift seam STITCH exists to document. Only stop when there's a single undifferentiated codebase with no such seam: "/stitch needs ≥2 contract-bound codebases; this looks like one codebase — use /codemap."

Step 1: Resolve paths & output target

• BACKEND_ROOT = <project_root>/<backend folder> (the one role=backend entry)
• FRONTEND_ROOTS = list of <project_root>/<folder> for all non-backend roles
• STITCH_FILE = <project_root>/STITCH.md by default. Override: if projects_groups[<tag>] contains a stitch_path field, use that (relative to <project_root>).

For create mode, require BACKEND_ROOT/CODEMAP.md and each frontend_root/CODEMAP.md. If any missing, list what's missing and recommend running /codemap create in each affected repo first.

Step 2: Load template (create mode only)

Start from ${CLAUDE_PLUGIN_ROOT}/template/stitch/STITCH.template.md. Fill Group identity with:

• Group tag
• Backend repo folder name + git rev-parse HEAD if git available
• Frontend repo folder names + revisions
• CODEMAP absolute paths for each repo
• Configured STITCH_FILE path

Step 3: Build sections 2–5 (create + section modes)

Using the loaded CODEMAPs, populate:

• 2. Auth stitch — token path FE → BE. Source: FE auth slice/hook + BE auth middleware/JWT handler. Table rows: step | location (file) | notes. Mermaid optional, keep minimal.
• 3. Endpoint stitch — union of FE RTK/fetch calls → BE routes. Normalize paths (strip env prefixes, trailing slashes). Table columns: FE hook/client | HTTP method | FE file | Path | BE urls module | View/handler | Permission | Notes.
• 4. Entity stitch — when traceable from CODEMAP model/serializer/type tables. Columns: Domain | FE type/schema | BE serializer | Model | Notes.
• 5. Integration stitch — external services from backend CODEMAP's Integrations section; note FE usage where mentioned. Columns: Service | Env keys | Owner repo | Files | FE usage.

Only populate cells with information that appears in the loaded CODEMAPs. Leave cells blank rather than inventing.

Step 4: Drift log (create + diff modes)

Precedence (check in order):

1. User-provided script — check for <workspace_root>/analyze-stitch.sh or <workspace_root>/analyze-stitch.py. If either exists, invoke with JSON stdin:

   {"backend_root": "<abs path>", "frontend_roots": ["<abs path>", ...], "group": "<tag>"}
   

   Expect JSON stdout:

   {"fe_orphans": [{"call": "...", "file": "..."}, ...], "be_orphans": [{"route": "...", "file": "..."}, ...]}
   

   Label output section: "Drift source: user script (analyze-stitch.)"*.

2. CODEMAP-based (default expected path) — check both CODEMAPs for required endpoint sections:

   • Backend: look for URLConf tree section (match heading like ## N. URLConf or similar). Parse endpoint rows.
   • Frontend: look for API client / RTK Query / endpoint table section. Parse endpoint definitions.
   • If both present → normalize to method + path tuples, diff the sets. Label: "Drift source: CODEMAPs (sections: <backend section name>, <frontend section name>)".

3. Missing CODEMAP endpoint data — prompt user explicitly (do NOT silently fall through):

   STITCH drift detection requires endpoint sections in both CODEMAPs.
   Currently missing:
     - <backend_path>/CODEMAP.md: <missing section name>
     - <frontend_path>/CODEMAP.md: <missing section name> (if applicable)
   
   Recommended: run `/codemap section <missing section>` in the affected repo(s) first
   (better accuracy, self-improving as you maintain CODEMAPs).
   
   Fallback: proceed with grep-based drift (coarse — catches presence/absence,
   misses HTTP methods, dynamic paths, non-REST conventions). Output will be
   labeled "Drift source: fallback grep."
   
   Choose: [C]odemap (stop here, regenerate first) / [G]rep fallback (proceed now)
   

4. On [G]rep fallback — grep FE for /api/ strings (and api/v1/, apiSlice, fetch( variants), grep backend for route definitions (Django urls.py patterns, or equivalent). Compare normalized sets. L