skills/README.md

# skills

Engineering skills library — markdown `SKILL.md` files that plug into any
AI-coding harness.

For **Claude Code** this repo is a plugin, installed from the marketplace it
also hosts; that path carries the hooks and MCP servers too. For **Crush, Pi
and OpenCode** it is a plain library wired by `install.sh` as one directory
symlink per harness. See [`SKILLS_INDEX.md`](./SKILLS_INDEX.md#wiring-into-tools).

## What is a skill?

A skill is a single directory containing one or more markdown files. The
canonical entrypoint is `<name>/SKILL.md`. Additional reference material
lives alongside in the same directory (e.g.
`clean-code/references/code-smells.md`). Harnesses load skills on
demand — keep `SKILL.md` short and triggerable; push depth into
references.

See [`SKILLS_INDEX.md`](./SKILLS_INDEX.md) for the full catalogue with
descriptions and "use when" triggers.

## Install

### Claude Code — the plugin

```
/plugin marketplace add https://git.d-ma.be/mathias/skills.git
/plugin install skills@mathias
```

The plugin ships skills, the `secret-guard` + `pre-task-ritual` hooks, and the
brain/gitea/infra MCP servers as one versioned unit. Skills are namespaced
(`skills:tdd`). Updates land when `.claude-plugin/plugin.json`'s `version`
moves — CI bumps it on every release.

### Crush, Pi, OpenCode — `install.sh`

```bash
curl -fsSL https://git.d-ma.be/mathias/skills/raw/branch/main/install.sh | bash
```

Idempotent. It clones or fast-forwards the checkout, then populates one
**managed directory** and gives each harness a single link to it:

| Path | Target |
|---|---|
| `~/.agents/skills/` | a real directory, one symlink per skill (Pi reads this path directly) |
| `~/.agents/skills/<skill>` | `$SKILLS_CHECKOUT_DIR/skills/<skill>`, or another configured source |
| `~/.config/crush/skills` | `~/.agents/skills` |
| `~/.config/opencode/skills` | `~/.agents/skills` |

Total links are N + one per harness — not N x harnesses, which is what #23 was
actually about.

### More than one source of skills

`~/.agents/skills` used to be a single link straight at this checkout. That
encoded an assumption nobody had stated — that this checkout is the only source
of skills on the host — and on flamingo the only way to install this library
was to displace Anthropic's official set, which lived in Crush's directory.
Real capability loss dressed up as a tidy-up (#27).

Point `SKILLS_EXTRA_SOURCES` at any number of extra directories, colon
separated, each holding `<skill>/SKILL.md`:

```
SKILLS_EXTRA_SOURCES=~/.config/crush/skills.anthropic bash install.sh
```

- The checkout is always first and always wins a name collision — but the
  collision is **logged**, never resolved in silence. Quietly picking one is
  how stale content wins.
- Removing a skill from a source removes its link on the next run.
- Anything in the managed directory that is not a symlink is reported and left
  alone. install.sh does not delete content it did not create.
- The source list is recorded at `~/.agents/skills-sources` so `bin/doctor`
  can tell a link into a known source from a link into a forgotten one.

### Where the checkout must live

`SKILLS_CHECKOUT_DIR` defaults to `~/.local/share/skills`, and that default is
load-bearing: it is **host-local, outside any synced or shared directory**.

On this fleet `~/dev` is an iCloud folder shared by flamingo and iguana, and it
spans two path roots — `/Users/mathias` on the Macs, `/home/mathias` on koala.
A checkout there is a git working tree with two concurrent writers, and any
absolute symlink stored there is broken on one side by construction. That is
what produced 243 dangling links across 12 repos (#23). Do not "fix" the
default to point into `~/dev`.

### Per-host env-var overrides

| Env var | Default |
|---|---|
| `SKILLS_REPO_URL` | `https://git.d-ma.be/mathias/skills.git` |
| `SKILLS_REF` | `main` (set to e.g. `v0.4.0` to pin a release) |
| `SKILLS_CHECKOUT_DIR` | `$HOME/.local/share/skills` |
| `SKILLS_SKIP_FETCH` | unset (`1` wires an existing checkout without touching HEAD) |
| `AGENTS_SKILLS_DIR` | `$HOME/.agents/skills` |
| `CRUSH_SKILLS_DIR` | `$HOME/.config/crush/skills` |
| `OPENCODE_SKILLS_DIR` | `$HOME/.config/opencode/skills` |
| `SKILLS_EXTRA_SOURCES` | unset (colon-separated extra source directories) |

Antigravity and Mistral Vibe targets were removed — unused.

## Checking a host

```bash
task doctor      # or bin/doctor
```

Reports dangling links, links into a source nobody configured, skills in the
checkout with no link, stray entries, leftover per-skill Claude symlinks, and a
Claude Code plugin sitting on an older generation than the host already has.
Non-zero exit on drift. It also runs at session start via the plugin, so a
drifting host says so rather than waiting to be discovered.

All of that compares copies already on the machine — deliberately, since it
runs in a session hook where latency shows. That leaves one case invisible: a
host where the checkout, the marketplace clone and the installed plugin all
agree, and all three are a release behind origin.

```bash
task doctor -- --online     # or bin/doctor --online
```

One `git ls-remote` against origin, opt-in. Belongs in a scheduled per-host job,
not the session hook. An unreachable remote is reported as its own fault rather
than as staleness — "I could not check" and "you are behind" are different
answers and only one of them is about the host.

## Versioning

Every commit to `main` is auto-tagged as a semver release by the
`.gitea/workflows/release.yml` action. Bump direction follows the commit
footer:

- `Bump-Type: major` → `X.0.0`
- `Bump-Type: minor` → `0.Y.0`
- *anything else* → `0.0.Z` (patch, the default)

Consumer projects can pin a version by setting `SKILLS_REF=v0.1.0`
before `task skills:install`; default is `main` for always-current.

## Contributing a skill

1. Add a directory `skills/<short-kebab-name>/`.
2. Create `skills/<short-kebab-name>/SKILL.md` with this frontmatter — all four
   keys are gated by `task check`, and the index table is generated from the
   last three:

   ```yaml
   ---
   name: <short-kebab-name>
   surfaces: [claude-code, library]   # any of claude-code | library | chat
   summary: "<one line for the index table>"
   use_when: "<the trigger, for the index table>"
   description: <the paragraph the model selects on>
   ---
   ```

   Then: one-paragraph purpose, triggers ("use when …"), mechanics.
3. Run `task index` and commit the regenerated `SKILLS_INDEX.md`. Do **not**
   hand-edit the table — `task check` regenerates it and fails on a diff.
4. Pressure-test it before shipping: run the scenario against a subagent that
   does *not* have the skill, write the skill against what that run actually
   did, then re-run with it. See `superpowers-writing-skills` and #19.
5. Commit directly to `main`. Conventional-commit prefix
   (`feat:` / `fix:` / `docs:`). Add `Bump-Type: minor` footer when
   adding a new skill or expanding scope; default patch covers edits.

This repo is markdown-only and public — never include secrets, client
names, or anything under NDA in a skill.

## Mode 2 routing candidates

These notes used to sit in each SKILL.md as a `## Mode 2 Routing Note` section.
They changed nothing about how the skill is invoked — several said so outright —
and cost context on every load, so they live here instead. Nothing in the repo
depends on this table; it is a record of which skills looked mechanical enough
to route to a local model, should a routing layer ever exist.

| Skill | Note |
|---|---|
| `cad-babysit` | Phases 2-4 (reading comments/logs, classifying fault vs outcome) are judgment-heavy and should stay Mode 1. Phase 1 (running `cad stuck` and grouping its output) is mechanical and a Mode 2 routing candidate once Plan 6 ships the routing pod. |
| `code-review` | This skill is invoked identically in Mode 1 (cloud Claude) and Mode 2 (client-local with supervisor routing). The routing layer (Plan 6) does not exist yet; treat this skill as Mode 1 only for now. Findings format and severity classification are unchanged across modes. |
| `debug` | This skill produces high-volume mechanical output (hypothesis enumeration) and is a candidate for Mode 2 routing to a local model in the future. Until Plan 6 ships the routing pod, treat as Mode 1 only. The hypothesis format and discipline are identical regardless of which model generates them. |
| `feature-spec` | Spec writing requires interpretation of intent and tradeoff reasoning — work where Claude generally outperforms a 9-13B local model. This skill is intentionally **not** a Mode 2 routing candidate. In Mode 2, the routing layer should leave `feature-spec` calls on Claude. |
| `session-retrospective` | Reading long session logs and pulling themes is high-volume, mechanical pattern-recognition work — a strong Mode 2 routing candidate. Until Plan 6 ships the routing pod, treat as Mode 1 only. |
| `tdd` | This skill is invoked identically whether the agent is running in Mode 1 (cloud Claude, no routing) or Mode 2 (client-local, supervisor routing layer). The routing pod (Plan 6) does not exist yet; until it does, treat this skill as Mode 1 only. The discipline does not change between modes — only the model behind the call. |
| `trainer` | Trainer is the same shape as `session-retrospective` — long-context reading, mechanical filtering — and is a Mode 2 routing candidate. Until Plan 6, treat as Mode 1 only. |