A role can run on a provider alone, or on an agent the project installed — a directory of code and instructions that npx agentskit add <id> copies into the repository.

# agents.registry.yaml
schemaVersion: 1
roles:
  builder: builder-1
  reviewer: reviewer-strict
agents:
  builder-1:
    provider: claude
    model: sonnet
    path: agents/builder-1
    instructions: AGENT.md
  reviewer-strict:
    provider: codex
    path: agents/reviewer-strict
    instructions: agent.ts

The copy in the repository is the version, and git is its history. There is no runtime fetch, no floating tag, no "latest" that changes under a running loop.

What loop doctor checks

The agents.registry check confirms every path exists and says which instructions file it found:

agents.registry  passed  builder-1 → agents/builder-1/AGENT.md ·
                         reviewer-strict → agents/reviewer-strict/agent.ts (code — improvements go to a human)

A registry pointing at a directory nobody installed is a failure, not a warning: every run for that role silently falls back to the provider alone, and nothing else in the loop would say so.

Code is a perfectly good agent

It only changes who applies an improvement. With agents.autoImprove, the retro may append one dated note to a markdown instructions file that already exists. For an agent that is code — or one whose declared instructions file is not there — the proposal is recorded as needs-human, with the note and the evidence intact, for a person to apply.

The previous behaviour appended an HTML comment to whatever the registry named, and created an AGENT.md out of nothing when none existed. Neither is an improvement; the first is a syntax error.

What is never automatic

• architect and reviewer — the critical roles — are never auto-changed, whatever the config says.
• More than agents.maxAutoLines lines is a proposal, not a change.
• Publishing anything back to the registry is a human's gesture, always.

See self-improvement for the eval gate that decides whether a change is adopted at all.