Skill packs

A crew's directive has three parts: guidelines (the prose an AGENTS.md would carry), resources (what the seat looks after), and skills — named procedures, each with a trigger saying when it applies.

Guidelines and resources are yours to write. Skills are the part somebody else can have written: how a bot PR gets triaged, what to read before proposing a rotation, what a refusal is supposed to look like. A skill pack is that know-how as a versioned file you can review, install onto a seat, update in place, and take back off.

A pack is not authority

Installing a pack changes no cap, no whitelist, no session scope, and no governance rule. It is instruction, and instruction is the layer with no enforcement behind it — which is exactly why a pack must not be able to imply capability it has not got.

That is what requires is for. A pack names the flows, connector routes and MCP tools its procedures call, and an install is refused, never trimmed when this deployment does not have one of them. Installing the skills that happen to fit would leave you a directive that reads complete and an agent holding a procedure for a tool that is not there.

A pack body is also untrusted text once it comes from anywhere but you: it lands in a system prompt, so treat an installed third-party pack with the care you would give a message in the thread.

The format

JSON. A pack travels the same paths a flow definition does — an HTTP body, a file, a marketplace payload — and those are already JSON.

{
  "id": "github-pr-triage",
  "version": "1.0.0",
  "name": "GitHub PR triage",
  "summary": "How the crew works a dependency-bot pull request.",
  "scope": "agent",
  "requires": {
    "flows": ["bot-pr-triage", "dep-fix-loop"],
    "connectors": ["github.get_pull_request", "github.merge_pull_request"],
    "mcpTools": ["lacrew_check_policy"]
  },
  "skills": [
    {
      "id": "triage-a-bot-pr",
      "name": "Triage a dependency-bot PR",
      "trigger": "A pull request from a dependency bot is open and nothing has classified it yet.",
      "body": "Run the `bot-pr-triage` flow with owner, repo and number…"
    }
  ]
}

Bounds: 20 skills per pack, 400 characters of trigger, 4,000 of body — and the whole directive still has to render inside its own ceiling (8,000 characters), which is checked at install.

Installed skills carry provenance

An installed skill stores source: {pack, version, skill} alongside the text. Nothing renders it — it is provenance, not instruction — and it buys two things:

• Uninstall is exact. Removing a pack removes what that pack put there. A skill you wrote by hand has no source, and nothing matches on name, so your own work cannot be taken with it.
• Update replaces in place. A new version of a pack replaces its own skills in the slots they already occupied, leaving the ones around them alone.

From the CLI

lacrew skills list                 # packs that ship
lacrew skills show github-pr-triage

# against a running orchestrator (ORCH_URL / --url, token via ORCH_TOKEN)
lacrew skills list --url http://127.0.0.1:8788   # adds what this deployment is missing
lacrew skills diff github-pr-triage --agent 0xSEAT      # what installing would change
lacrew skills install github-pr-triage --agent 0xSEAT
lacrew skills install --file ./my-pack.json --agent 0xSEAT
lacrew skills installed --agent 0xSEAT
lacrew skills remove github-pr-triage --agent 0xSEAT
lacrew skills export --agent 0xSEAT --id my-pack > my-pack.json

diff is the read before the write. An install reports how many skills it replaced, which answers did something happen and not what does it say now — and a pack body is instruction that lands in a model's system prompt. Each skill is matched on its id, so a rename reads as a change rather than as a removal plus an addition, and a skill the new version dropped is listed as one the install will take away.

github-pr-triage: 0.9.0 → 1.0.0 on 0xSEAT

  ~ Triage a dependency-bot PR  [triage-a-bot-pr]  (body)
  + Repair a red dependency PR  [repair-a-red-pr]
  - A skill this version dropped  [retired]

1 added · 1 changed · 1 removed · 1 unchanged

export lifts a seat's skills back out as a pack — hand-written ones included, since those are the ones a restore would otherwise lose. A hand-written skill with no trigger is exported with the gap named in the field rather than dropped.

Over HTTP

The install refuses in three distinguishable ways, because they are fixed in different places:

• 400 — the pack is malformed. The body lists every reason.
• 409 — a requirement is unmet. The body names the missing flows, connector routes and tools; register them and install again. A connector counts as registered only when its credential is actually set — a connector with no token is one every call through fails on, which is the same defect an unregistered one causes.
• 413 — the merged directive would blow the rendered ceiling. Remove a pack or shorten a layer.

Both outcomes are audited: SkillPackInstalled and SkillPackRemoved carry the pack id, version and counts — never the skill bodies, which the directive itself serves in full.

There is deliberately no install-onto-a-crew route. The orchestrator holds per-agent layers with opaque labels and keeps no roster: which seats make up a crew is the caller's answer, and a route that took a crew id would have to guess at one. So a crew-wide install is a fan-out the caller performs seat by seat — which is also the only shape that can report that four seats took the pack and the fifth was unreachable, instead of one status for five different outcomes.

What ships

lacrew skills list

The packs LaCrew ships are the procedure half of verticals that already exist here: their flows are shipped templates and their connector routes are shipped presets. That constraint is deliberate — a first-party pack naming a route no preset serves would be invention presented as configuration.

They carry no resources. Which repos, venues or accounts a crew looks after is your answer, exactly as it is for a crew blueprint: a pack that named repositories would be putting somebody else's targets into your directive.