sync

name	sync
allowed-tools	Bash, Read, Grep, Glob, Write, Edit, Task
description	Run /sync as the last step after a change is complete, around merge, to keep durable knowledge current. Updates root and nested AGENTS.md, reconciles the scope from repo evidence, and flags ADRs the change made stale. Surgical, additive edits only.

Output style (plain words, no dashes)

Write everything this skill produces (files, reports, messages to the engineer) in plain simple language; keep technical terms that carry real meaning but explain each in plain words. Never use dashes as punctuation (no em dash, en dash, or punctuation hyphen); use short sentences, commas, or parentheses instead.

What this skill does

Closes the loop on a completed change: syncs AGENTS.md files, the scope, and linked ADR **Status**: lines to what the repo now shows, and flags what it must not edit (stale ADRs, curated prose). The Boundaries table below is the exact contract.

agent-prompt.md is the single source of truth for the maintenance rules; SKILL.md covers only orchestration. The main thread reads it and does the maintenance itself (see Step 3).

Canonical file: durable context lives in the tool-agnostic AGENTS.md; CLAUDE.md is only a pointer to it. /sync edits/creates both, treating them only as targets, never as a change source.

Boundaries (these keep the skill from sprawling)

Action	/sync	Owner
Edit existing root/nested AGENTS.md	✅ maintains	/sync
Reconcile root AGENTS.md's ## Build approach line to the scope header's approach (surgical single-line edit, like the stack)	✅ maintains; flags a curated divergence	/sync
Add a one-line pointer to design.md (the UI design system) in the nearest AGENTS.md when a change establishes one	✅ maintains (pointer only)	/sync
Create nested <area>/AGENTS.md for an area net-new in this change	✅ creates (diff = full area context) + adds root pointer	/sync
Create nested doc for a pre-existing undocumented area (only sliced by the diff)	❌ flags "run /audit"	/audit
Create or restructure the root AGENTS.md	❌ flags "run /audit"	/audit
Reconcile an ADR's **Status**: line to its feature's scope status (planned→Proposed, in-progress→In Progress, done→Accepted)	✅ Status line only	/sync
Edit an ADR's content / supersede it	❌ flags as stale	/architect
Reconcile the scope — for the relevant workspace's scope file only (not all of docs/scope/) — tick any completed sub-task from repo evidence (code, tests, AGENTS.md), advance status	✅ corrects	/sync
Add / reorder features or sub-tasks in the scope	❌ leaves alone	/scope
Overwrite or rewrite curated AGENTS.md prose	❌ flags conflict instead	human

The dividing line on creation is context, not policy: create only when this change shows you the whole area; defer to /audit when the area predates the change and you've seen only a slice. When unsure, flag instead of creating.

Asks vs acts

Acts. Pauses only when there is nothing to sync (empty change set). Every edit to curated files is listed in the report so you can review or revert.

Artifact ownership

Owns exactly what the Boundaries table grants and writes nothing else. As the universal sub-task reconciler it ticks any scope sub-task it can verify from repo evidence (sweeping the /test//audit//sync sub-tasks other skills don't tick) and advances feature status; exact rules in agent-prompt.md.

Artifact base. ADRs and the scope live under docs/ by default, or .workflow/ if docs/ is a published docs site; use whichever base exists in the repo (paths here assume docs/).

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Portability (any OS, any agent)

• Commands: git is the only required CLI and behaves the same on every OS, run the git lines as shown. Other shell snippets are POSIX reference, not literal scripts: don't assume find, grep, sed, cat, test/[ ], ls, or xargs exist; use your agent's cross-platform file tools and apply branching logic yourself rather than shell if/variables/redirects.
• Bundled files: referenced by paths relative to this skill's folder. Resolve the folder to an absolute path (you already resolve these relative paths) and read agent-prompt.md yourself at write time (Step 3), not during pre-flight.
• The whole maintenance runs inline on the main thread, following the exact rules in agent-prompt.md (authoritative).

Execution

1. Scope the change set (cheap — with per-file status)

Freshness first (teams): git fetch --quiet; if git rev-list --count HEAD..origin/$BASE > 0 you are behind origin/$BASE, warn the engineer to pull first, a teammate may have already synced these docs.

Base: main if git rev-parse --verify main succeeds, else master. Current branch: git rev-parse --abbrev-ref HEAD. Use --name-status (not --name-only); the net-new-area and orphan-cleanup logic need Added vs Modified vs Deleted per file.

• Current branch is the base, mode uncommitted: git diff --name-status HEAD.
• Otherwise, mode branch: git merge-base "$BASE" HEAD, then git diff --name-status <merge-base>.

Either way, add untracked files from git ls-files --others --exclude-standard, each prefixed with an A status (matching the --name-status format). Note the mode, base, and merge base for the write step.

De-duplicate, then filter to source files to sync from:

• Drop documentation and config (AGENTS.md at any level, docs/**, *.md, test-preferences.json, lock files, generated output); /sync reads these as targets/context, never as a change source.
• Drop test files (*.test.*, *.spec.*, __tests__/, etc.); tests aren't durable area conventions.
• Keep the D (deleted) entries in a separate list; they drive orphan cleanup (Step 3) though they aren't synced from.
• Keep dependency manifest changes in a separate list for tool discovery, even if they are config rather than source: package.json, pyproject.toml, requirements*.txt, go.mod, Cargo.toml, composer.json, Gemfile, pubspec.yaml, mix.exs, *.csproj, and equivalent package manifests. Lock files are signals only; do not pass lockfile contents.

If no source files and no dependency manifest changes remain (only docs/tests/lock/generated files changed), stop, nothing to sync. Do not spawn.

2. Locate the context files and ADRs (paths only — do NOT read them here)

Using your agent's file-search/glob tools:

• Note whether a root AGENTS.md exists.
• Find every AGENTS.md (root + nested), excluding node_modules/ and .git/.
• Find all ADRs under docs/adr/ whose names start with a digit, sorted.
• Find the scope file(s) whose workspace/features the diff actually touches (in a monorepo, a changed file's workspace apps/<x>/… selects docs/scope/<x>/); never read or pass all of docs/scope/.

Note the paths plus the changed-file list and diff command; read the files at write time. Read root AGENTS.md contents now (short and useful to anchor on). For each changed file, note its nearest enclosing directory with a AGENTS.md (root or nested); that's the context file most likely to need an update.

2.5 Discover Agent Skills and optional MCPs for newly added tools

Run only when dependency manifests changed or the diff clearly adds a significant external tool. Skip ordinary utility libraries unless they define a durable workflow or integration.

• Identify newly added significant packages/tools from the manifest diff, not the full lockfile: framework, router, styling/UI kit, database, ORM/query layer, auth/session, payments, email/notifications, storage/uploads, search, queue/background jobs, AI provider/vector DB, browser/runtime testing, observability, hosting/deploy. Include package names and common aliases from manifests. Do not stop after the first technology.
• Filter out anything already covered by installed skills, connected MCPs, or AGENTS.md declined entries.
• Isolate the searches in a read-only subagent (capability-first). Hand the remaining set to a discovery subagent rather than searching on the main thread: spawn it in the background (non-blocking) if your agent supports that, else blocking; set its model explicitly to a fast, low-cost tier (do not inherit the session model; on Claude Code spawn it as the researcher subagent type, which pins the model); it returns only the compact candidate list. This keeps the search output out of /sync's bounded context. No subagent → search inline; no search capability → skip and note it. The offer panel stays on the main thread.
• For each remaining item, run npx skills find <tool-or-package>; if weak, retry aliases from package/org names. Collect every credible Agent Skill candidate and confirm with npx skills add <owner>/<repo> --list when practical. If the CLI is interactive/unavailable, search "<tool>" "agent skill" and confirm before offering.
• MCP search is optional: connector list first, else "<tool>" "MCP server" per item. MCP is recommended upside, not required.
• Keep discovery capped and cacheable: max 5 web searches and 8 fetched pages total, official registry/docs first. Reuse docs/.agent-cache/tool-discovery/<slug>.md when under 30 days old, after filtering installed/declined items.
• Offer all Agent Skill matches in one multi-select panel, grouped by technology: "Install relevant Agent Skills for newly added tools?" plus skip/decline. Then offer MCPs separately: "Optional MCP servers that could help these tools" plus skip/decline. Never auto-install or auto-connect.
• Install selected skills with npx skills add <owner>/<repo> -y. For MCPs, point to the user's connector/MCP settings; once connected the tools are used automatically.
• Carry the result as INSTALLED_SKILLS_OR_NONE, MCP_SERVERS_OR_NONE, and DECLINED_TOOLS_OR_NONE and record durable lines in the right AGENTS.md file when you write. If nothing was found or no capability exists, treat as none.

3. Do the maintenance (main thread)

The main thread does the maintenance itself; it never hands the AGENTS.md / scope / ADR-status edits to a subagent. Read agent-prompt.md now (only now, at write time) and follow it exactly; it is authoritative for the maintenance rules. The diff reading is the one thing you may offload, and only for a large change set, to a read-only scout subagent on the cheapest model (Claude Code: haiku) that returns a compact map. Stay within the same boundaries the old tool grant expressed: Edit existing docs, scope, and ADR **Status**: lines; Write strictly for a net-new-area nested AGENTS.md; no root creation, no ADR content edits (Status line only), no shallow nested docs for established areas (these are rules in agent-prompt.md).

The inputs to apply:

1. MODE, BASE, MERGE_BASE, CHANGED_FILES (name-status changed-source list), DIFF_COMMAND (exact git diff command)
2. DELETED_PATHS (deleted paths, for orphan cleanup)
3. ROOT_AGENTS_MD (root AGENTS.md contents), NESTED_PATHS (nested AGENTS.md paths)
4. ADR_PATHS (all ADR paths, for Status-line reconciliation and staleness flagging)
5. FILE_TO_CONTEXT_MAP (changed file → nearest context file)
6. SCOPE_PATH_OR_NONE (relevant workspace scope path(s), not all of docs/scope/; also the source of each linked feature's status for ADR Status-line reconciliation)
7. INSTALLED_SKILLS_OR_NONE, MCP_SERVERS_OR_NONE, DECLINED_TOOLS_OR_NONE from Step 2.5

4. Relay the result

If the maintenance failed or produced no parseable summary, report that and re-do it, don't fabricate a result (a genuine NOTHING_TO_SYNC is a valid success; a crash or empty output is not). Otherwise relay the compact summary:

## /sync complete

**Scope**: <N> changed files

**AGENTS.md updated**:
- `<path>`, <what was added/corrected, one line>   (or "no updates needed")

**AGENTS.md created** (new area):
- `<area>/AGENTS.md`, <what conventions it captures> (+ root pointer added)

**Orphans cleaned** (after deletions):
- `<path>`, <removed orphaned nested doc / fixed broken pointer>

**Scope reconciled** (relevant workspace):
- `<feature>`, <ticked sub-tasks / status planned→in-progress→done to match the diff>   (or "no scope, or already accurate")

**ADR statuses reconciled** (Status line only):
- `docs/adr/<file>`, <Status Proposed→In Progress→Accepted to match the feature's scope status>

**ADRs flagged stale** (run /architect to update or supersede):
- `docs/adr/<file>`, <why the change makes it stale, or status mismatch sync couldn't safely resolve>

**Context gaps** (run /audit, area too established for /sync to document from the diff alone):
- `<area>`, <pre-existing undocumented area only sliced by this change>

**Conflicts left for you** (not auto-edited):
- `<path>`, <curated content that would need rewriting; decide manually>

Omit any section with no items. If everything was already current and nothing is stale, say so in one line. /sync does not run /architect or /audit for you; it points, you decide.

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Subagent prompt template

See agent-prompt.md.