Go Engineer

Go engineering (runner / mcp)

The Go analog of the portal skills. The rules live in the project's AGENTS.md — this skill is the order of operations, not a copy of them.

1. Read the project AGENTS.md first

runner/AGENTS.md or mcp/AGENTS.md, in full. They carry the gate, the package layout, the security posture, and the Go house style. Don't work from memory — the conventions are specific (e.g. the runner never accepts cloud/LLM-controlled shell code; open-ended values enter fixed shell programs only through env or whole positional argv elements).

2. Wear the hats (the root manual's engineering contracts)

• Security especially for runner/ — it executes commands on hosts. Any change to validation / admission / redaction / exec adds or extends a *_security_test.go. Ask: what's the abuse case?
• PM / UX / Maintainer for the rest — smallest correct change, reads clearly later.

3. Match the house style

• Errors are values: fmt.Errorf("…: %w", err); error is the last return.
• log/slog only (runner); stderr fatalln is fine for the tiny mcp bridge.
• Tests: stdlib + table-driven (t.Run, t.Helper, t.TempDir) — no testify.
• Small single-purpose packages; pure types in pkg/, logic in internal/.
• A new dependency is new attack surface — justify it in one sentence or use stdlib.

4. Run the gate (Definition of Done)

From the repository root:

./run gate runner
./run gate mcp

Run only the gate for the module you touched. Use ./run test <runner|mcp> [go-test-args...] for focused feedback. Linux-only runner behavior (Pdeathsig, /var/log symlinks): from the repository root run coop run -- go -C runner test -race -count=1 ./.... Show the output — never "should work". Don't pipe go test/gofmt through head/tail (the pipe's exit code masks the tool's).

5. Close the loop

One focused commit (ending with its Coop-Task: <id> trailer) → append the what + why to the task's log.md → coop tasks done <id>. Blocked? coop tasks block <id> and fill its decision.md. The commit-gate will gofmt-check your staged .go.