docs-update

name	docs-update
description	Refresh the project's docs in three places, all keyed on per-folder SHAs that record what was last reconciled. (1) `docs/map/` - concept-first codebase digest the conceiving agents (requirements, design-spec, plan, issue-creation) read instead of grepping source. (2) `docs/requirements/index.md` - registry of requirement docs in `docs/requirements/`. (3) `docs/design/index.md` - registry of design docs in `docs/design/`. On refresh, each folder is diffed against its stored SHA; map leaves whose source files changed are regenerated, and requirements/design index entries are added/updated/removed for files added/modified/deleted in the diff. Run from the project root. First run bootstraps; subsequent runs diff-refresh.
user_invocable	true
allowed-tools	Bash(git *), Read, Glob, Grep, Write, Edit, AskUserQuestion
argument-hint	[optional: 'rebuild' to force re-bootstrap of docs/map/; otherwise auto-detect mode]

Docs Update

Refresh three doc surfaces in one pass, each tracked by its own SHA:

Surface	Folder	SHA stored in	Purpose
Codebase map	docs/map/	docs/map/index.md frontmatter	Concept-first digest the conceiving agents inject into their cached system prompt
Requirements registry	docs/requirements/	docs/requirements/index.md frontmatter	One-line summary per requirement doc; tells humans and agents what exists
Design registry	docs/design/	docs/design/index.md frontmatter	One-line summary per design doc; same role as requirements registry

The map regenerates leaves whose source files changed. The requirements and design registries add/update/remove their entries based on which .md files in their folder were added/modified/deleted in the diff. The .md files themselves are never touched - they are at HEAD and are the source of truth.

Argument: $ARGUMENTS

Style rules (apply to every file you write)

These rules are non-negotiable. Re-read them before writing each file.

• Agent-shape, not human-shape. Dense bullets. No narrative. No onboarding examples. No "this is great because...".
• Minimum words. If a sentence can be a fragment, make it a fragment. If a fragment can be cut, cut it.
• Synthesize, do not enumerate. "All webhook handlers verify HMAC and dedupe before dispatching" beats listing five handlers each doing the same thing.
• Concept-first (map leaves). A leaf describes WHAT a concept is and WHERE it lives. Never list a file and describe its contents - that inversion goes stale.
• Cite files by path. Optionally add line numbers or function names if pinpointing matters. Never paste code.
• One-line summaries (registries). Each entry in docs/requirements/index.md and docs/design/index.md is exactly one sentence. Lead with the noun (the user-observable behavior or the design concept), not the filename.

Step 1: Mode detection

Run from the project root (the directory containing the project's source tree). The skill operates on the current working directory.

Per-surface mode detection:

map_mode  = "bootstrap" if not (cwd / "docs/map/index.md").exists() else "refresh"
reqs_mode = "bootstrap" if not (cwd / "docs/requirements/index.md").exists() else "refresh"
des_mode  = "bootstrap" if not (cwd / "docs/design/index.md").exists() else "refresh"

if $ARGUMENTS == "rebuild":
    map_mode = "bootstrap"  # only the map honors `rebuild`; registries are cheap to refresh, no full re-bootstrap needed

If docs/requirements/ or docs/design/ does not exist as a directory, skip that surface entirely (announce in the summary). Some projects have only one or neither.

Announce per-surface modes in one line, then proceed.

Step 2: Pre-flight checks (all surfaces)

Before doing anything destructive:

Condition	Behavior
git status shows merge conflict markers	Ask user to confirm running anyway. Abort if no.
git status shows uncommitted changes	Ask user to confirm. Abort if no. Note: refresh will diff against HEAD, so uncommitted work is invisible.
Not in a git repo	Abort with a clear error.

Use AskUserQuestion for the prompts. Do not use multiple-choice when a yes/no is enough.

Surface 1: docs/map/

The map is the largest and most opinionated of the three. Bootstrap requires user-confirmed concept discovery; refresh is mechanical.

Map / Step 3 (bootstrap mode): discover concepts

The goal is to produce a list of 10-25 domain concepts. Each concept becomes one leaf.

What "concept" means: a coherent piece of behavior or knowledge that can be discussed independently. Examples from a Django app: "request authentication", "ORM model conventions", "background task dispatch", "billing reconciliation". Examples from a workflow-orchestration service: "job lifecycle", "webhook routing", "retry patterns", "state storage and retrieval".

How to discover

In this order:

1. Read existing high-level docs. README.md, CLAUDE.md, docs/index.md, docs/architecture.md, docs/decisions.md, docs/gotchas.md, docs/key-files.md if present. These often already name the concepts; harvest them.
2. Read top-level structure. ls src/ (or equivalent). Each top-level package is usually one concept or contains a few.
3. Read recent commits. git log --oneline -50. Recurring themes signal active concepts.
4. Sample for vocabulary. Read 5-10 source files that look central (entry points, service classes, main models). Note the named concepts they reference.
5. Combine into a candidate list. Aim for 10-25 concepts. Each name is a noun phrase (1-4 words).

Propose to user

Present the candidate list as a bulleted list with a one-line "what it covers" gloss for each. Use AskUserQuestion to ask:

"Concept list - want to add, remove, rename, or accept as-is? You can edit freely; nothing is written until you confirm."

Iterate until the user approves. Then proceed.

Map / Step 4 (bootstrap mode): generate the index

Write docs/map/index.md using this template:

---
generated_at_sha: <full SHA from `git rev-parse HEAD`>
commits_since: 0
---

# <Project Name> Map

<2-4 sentences: what this project is, primary tech stack, deployment target. Synthesize - do not enumerate.>

## Concepts

| Concept | Leaf | When to load |
|---------|------|--------------|
| <Concept Name> | [<concept-slug>.md](<concept-slug>.md) | <one-line trigger phrase: when an agent should read this leaf> |
...

## Cross-cutting conventions

- <bullet: convention that applies project-wide, e.g. "Soft deletes only - never DELETE; filter `WHERE deleted_at IS NULL`">
- <bullet>
- <bullet>
(5-12 bullets total. These belong here only because they cut across leaves; concept-specific patterns go in the leaf.)

The "When to load" column is the most important field in the entire map. It determines whether agents pull the right leaf at the right moment. Make each entry trigger-phrase-shaped: think "if the user is talking about X, load this leaf".

Map / Step 5 (bootstrap mode): generate each leaf

For each concept, write docs/map/<concept-slug>.md using this template:

---
generated_at_sha: <same SHA as index>
commits_since: 0
concept: <Concept Name>
---

# <Concept Name>

<1-2 sentences: what this concept is and why it exists. Synthesize.>

## Files

- `<path>`: <what role>
- `<path>`: <what role>
(Path is enough when the file is small or single-purpose. Add `:line-range` or `:function_name` when the concept lives in part of a larger file.)

## Key types and functions

- `<TypeName>` (`<path>`): <one-line role>
- `<function_name>` (`<path>:<line>`): <one-line role>
(Include only the 3-8 names an agent will need. Skip if the file list above already makes the concept obvious.)

## Patterns and invariants

- <bullet: behavior that must hold, conventions, gotchas specific to this concept>
- <bullet>
(Skip the section if there are none. Do not pad.)

## Related

- See [other-leaf.md](other-leaf.md) when <when>.
(0-3 cross-references. Skip if none.)

Discover the file paths by reading code. Use Glob and Grep to locate where the concept actually lives. Do not guess paths - verify they exist before writing them in.

Keep each leaf under ~1500 tokens. If a leaf is heading past that, that is a signal the concept is too coarse - propose splitting it before writing (see Map / Step 6).

Map / Step 6 (bootstrap mode): split-on-write check

Before finalizing each leaf, look at its draft size. If above ~1500 tokens or referencing more than ~12 files, ask the user:

"Concept '' has grown to tokens / file refs. Split into sub-concepts? Suggested split: ."

If yes, propose two or more sub-concept names, get user confirmation, write each sub-leaf, and update the index accordingly.

Map / Step 7 (bootstrap mode): handle existing key-files.md

If docs/key-files.md exists, the map supersedes it. Do not delete it automatically. Tell the user:

"docs/key-files.md is now superseded by docs/map/. Delete it after reviewing the new map."

Map / Step 8 (refresh mode): diff against stored SHA

Read the SHA from docs/map/index.md's frontmatter. Run:

git diff --name-only <stored-sha>..HEAD
git rev-list --count <stored-sha>..HEAD   # for the new commits_since value

If the stored SHA is missing from history (rebased / squashed), ask the user:

"Stored SHA for docs/map/ is no longer in history. Choose: (1) full re-bootstrap, (2) bootstrap from merge-base with main, (3) skip and exit."

For options (1) and (2), proceed accordingly. For (3), exit cleanly.

Map / Step 9 (refresh mode): match changed files to concepts

Read every existing leaf's frontmatter and "Files" section. For each changed file from the diff:

1. Find the closest existing leaf by comparing the file's path and inferred role to the leaves' concept names and file lists. This is LLM judgment, not a string match.
2. If a leaf clearly fits, mark that leaf for regeneration.
3. If no leaf fits well (low confidence on the closest match), propose a new leaf. Suggest a name from the file's path and content. Ask user to accept or rename.
4. If multiple leaves are touched by the same file, regenerate all of them.

Do not ask the user about every match. Only ask when (a) creating a new leaf or (b) confidence is genuinely low.

Also check for deleted leaves referenced by the index but missing on disk. Ask:

"Leaf <concept>.md is in the index but not on disk. Choose: (1) regenerate, (2) drop from index, (3) skip."

Map / Step 10 (refresh mode): regenerate marked leaves

For each leaf marked for regeneration, rewrite it end-to-end using the leaf template. Do not patch in place. Update its generated_at_sha and commits_since headers.

For each new leaf, write it from scratch and add a row to the index.

Map / Step 11 (refresh mode): split-on-refresh check

After regeneration, re-check size for every regenerated leaf. If past the soft threshold (~1500 tokens or ~12 file refs), propose a split exactly as in Map / Step 6.

Map / Step 12: update the map index frontmatter

Update docs/map/index.md:

• Set generated_at_sha to current HEAD.
• Set commits_since to 0.
• Refresh the concept table to reflect any added, removed, or renamed leaves.
• Re-check the cross-cutting conventions section: anything new from the diff that applies project-wide?

Leaves that were not regenerated keep their own generated_at_sha and commits_since from the last time they were written. Do not touch their headers. To check current staleness of a specific leaf, a reader runs git rev-list --count <leaf_sha>..HEAD.

This per-leaf SHA model means the index's SHA tells you when the concept list was last reconciled, while each leaf's SHA tells you when its content was last verified. They can legitimately diverge.

Surface 2: docs/requirements/

A flat folder of .md files, one per requirement (e.g. docs/requirements/cd-pipeline.md). The skill maintains docs/requirements/index.md: a registry with frontmatter SHA + a table of one-line summaries per file. Bootstrap and refresh share most of the work; the only difference is whether you start from an existing index.

Reqs / Step 1 (bootstrap mode): build the registry from scratch

Skip if docs/requirements/ does not exist. Otherwise:

1. List every .md file directly under docs/requirements/ (one level, no subdirs unless the project actually uses them).
2. For each file, read it. Generate a one-sentence summary that names the user-observable behavior or feature. Lead with the noun, not the filename. Examples:
   • Good: "GitHub Actions deploys the API to staging on every push to main."
   • Bad: "cd-pipeline.md describes the deploy pipeline."
3. Write docs/requirements/index.md:

---
generated_at_sha: <full SHA from `git rev-parse HEAD`>
commits_since: 0
---

# Requirements Registry

| File | Summary |
|------|---------|
| [cd-pipeline.md](cd-pipeline.md) | <one-line summary> |
| [staging-environment.md](staging-environment.md) | <one-line summary> |
...

Sort rows alphabetically by filename so the diff between runs is small. Keep it as a flat table; do not group by topic - that is the map's job.

Reqs / Step 2 (refresh mode): diff against stored SHA

Read the SHA from docs/requirements/index.md's frontmatter. Run:

git diff --name-status <stored-sha>..HEAD -- docs/requirements/
git rev-list --count <stored-sha>..HEAD -- docs/requirements/

The first command yields lines like A path, M path, D path, R### old new (rename). Parse them.

If the stored SHA is missing from history, ask the user:

"Stored SHA for docs/requirements/ is no longer in history. Choose: (1) bootstrap registry from scratch, (2) skip this surface."

Reqs / Step 3 (refresh mode): apply add/update/remove

For each diff entry:

Status	Action
A path	Read the file. Generate one-line summary. Add a new row to the registry, sorted alphabetically.
M path	Re-read the file. Regenerate the summary. Replace the existing row. (Skip if the file's content semantically did not change - judgment call.)
D path	Remove the row from the registry.
R### old new	Remove the old row, add a new row with regenerated summary.
Anything else	Log and skip.

Update generated_at_sha to current HEAD and commits_since to 0.

If the diff is large (>20 changes), ask the user before applying:

" requirement files changed since the last registry update. Apply add/update/remove to the registry? (1) Yes, (2) Show me the list first, (3) Skip."

Reqs / Step 4: cross-check with map references

If any map leaf cites a requirement file in its "Related" section, those references survive automatically (we are not touching leaves here). But if a requirement was DELETED, scan map leaves for stale links to it and flag them in the post-run summary - do not auto-edit map leaves from this step.

Surface 3: docs/design/

Identical structure and rules to Surface 2. Substitute docs/design/ for docs/requirements/ and "Design Registry" for "Requirements Registry" throughout. The summary should describe the design decision or system, not the requirement.

Step 13: post-run summary

Print a one-screen summary covering all three surfaces:

• Map: mode (bootstrap or refresh), leaves written, splits performed, new leaves added, files skipped (untouched leaves)
• Requirements: mode, files added/updated/removed in the registry, total entries
• Design: same shape as Requirements
• Cross-surface notes: stale map references to deleted requirements/designs (if any), docs/key-files.md still present (if any)

That's it. Do not write a longer report; the diff itself is the artifact.

Failure mode reference

Situation	Behavior
No git repo	Abort with clear error
Merge conflict in progress	Ask user to confirm before running
Dirty working tree	Ask user to confirm before running
Stored SHA gone from history (any surface)	Ask: bootstrap that surface, or skip
Map leaf in index but not on disk	Ask: regenerate, drop from index, or skip
Map leaf grew past size threshold	Ask: split into sub-concepts (offer auto-suggestion)
Map diff touches a file no leaf covers	Propose new leaf; ask user to accept or rename
Requirements/design folder missing	Skip that surface, note in summary
Requirements/design diff is large (>20 changes)	Ask before applying; offer to show the list
docs/key-files.md exists at bootstrap	Notify user it is superseded by the map; do not delete

All prompts use AskUserQuestion.

What this skill does NOT do (deferred)

• Does not validate that paths cited in map leaves still exist (drift check beyond SHA + commit count).
• Does not check whether high-churn files lack any map leaf coverage.
• Does not edit the actual docs/requirements/*.md or docs/design/*.md files - the registries point at them, the files themselves are at HEAD and authoritative.
• Does not auto-edit map leaves when a requirement/design they reference is deleted - it flags the stale reference in the summary.
• Does not sync against external sources (Linear, other branches). The diff is always local-git from the stored SHA to HEAD.
• Does not run non-interactively. CI mode is future work; when added, every interactive prompt becomes a hard failure that the PR author resolves locally.

Style anti-patterns to avoid

After writing a file, re-read it and check:

• Did you write a paragraph where a bullet list would do? Cut it.
• Did you describe a file ("foo.py contains the FooService class which handles...")? Re-shape: lead with the concept, mention the file as evidence.
• Did you include onboarding-style "you might wonder why..." prose? Cut it.
• Did you list the same convention three times across leaves? Move it to the index's cross-cutting section.
• Did you write a registry summary that names the filename instead of the behavior? Re-write it leading with the noun.
• Did you exceed the soft size targets without proposing a split? Propose now.

Suggested next step after this skill runs

The map is consumed by the conceiving agents (requirements, design-spec, plan, issue-creation) via AgentContext.project_map. After the first map is written or a major refresh, verify the agent harness loads docs/map/index.md from the worktree and injects it into the cached system prompt. Run a single conceiving task end-to-end and inspect the trace to confirm the map shows up in the prompt and the agent uses it (i.e., loads leaves via read_file instead of grepping source).

The requirements and design registries do not feed the agents directly today - they exist for humans (and for future skills that want a quick one-line view of all requirements / designs without opening every file).