harness-subagent

Harness subagent

You are the parent. A child CLI does one bounded task and returns a report. You judge the report. The child is not an oracle.

The host decides which CLI, which model, and which effort. This skill does not rank jobs or pick a persona.

Delegate

1. Take the CLI and model from the user. Spoken names are in references/models.md. If they named neither, ask once. Do not launch your own CLI family unless they named it this turn. Cursor, cursor-agent, and Grok Bot are the cursor family. Grok Build is grok. Claude Code is claude. Codex is codex. Antigravity is agy.
2. Pick --effort from the tables in references/models.md when the task is large enough that the vendor default is a guess. Omit --effort to keep the CLI default. Prices are per token. Higher effort spends more tokens at the same rate.
3. Write brief.md in a new temp run directory. Use the shape below.
4. Run scripts/spawn.sh in the background. On Windows, invoke Git Bash with the script path as an argument. Do not put the brief inside a PowerShell double-quoted string. Write brief.md as UTF-8.
5. Wait until that process exits. Read report.md or last.md, plus capture-status.txt, plus the exit code.
6. Say what you agree with, what you do not, and what you will do. Do not paste the report as your whole answer.

& "$env:ProgramFiles\Git\bin\bash.exe" -- "<skill-dir>\scripts\spawn.sh" --backend codex --model Astra --effort high --project "D:/Code/app" --run "C:/Users/<you>/AppData/Local/Temp/harness-subagent/<id>"

--backend may be omitted when the model name belongs to one CLI. --resume-id continues that same child. Do not use --continue or --last.

A child must not delegate. spawn.sh sets HARNESS_SUBAGENT_RUN and refuses a second launch.

Brief

# YOU ARE THE WORKER. DO NOT SPAWN.
Do not load harness-subagent. Do not run scripts/spawn.sh.

## Task
One sentence.

## Where to look
Paths, commands, and exclusions.

## Already tried

## Done when

Name paths. Do not paste the repo. spawn.sh appends the report.md path. The child writes that file before it exits. The first line is VERDICT followed by the result.

Grok cannot be relied on to read the temp run directory. spawn.sh copies the prompt into the project for that launch and deletes the copy on exit.

When the child hits a limit

spawn.sh reads the CLI text for a reset time.

• The reset is known and within 24 hours. The script waits, then resumes that same session once. Claude Code's own auto-continue refuses waits longer than 24 hours (docs accessed 2026-09-22). This skill uses that cutoff for every CLI.
• There is no reset time, the reset is further away, the message is a credit or spend block, or a second limit arrives. The script stops. Stop with it. Tell the user the evidence and the time, if any. Wait for instructions. Do not switch CLI or model. Do not invent a reset time.

Health

scripts/health.sh prints one row per CLI. Columns are name, version, login, update. --update runs each vendor update command. Exit 0 when every installed CLI with a login check is logged in. A missing CLI is a failed row. broken means the binary is on PATH but its version check fails. A failed login check is retried once, because grok reports logged-out on the first call after token expiry while it refreshes silently.

CLI	Login check	Update
claude	claude auth status	claude update
codex	codex login status	codex update
grok	grok models must say logged in	grok update
agy	no login command	agy update
cursor-agent	cursor-agent status	cursor-agent update

Capture

spawn.sh writes last.md, capture-status.txt (ok, ok-report, usage-limit, or no-verdict), and session.json. A report containing VERDICT wins over the final stdout, because Claude's last message is only the last turn. ok means text was captured. It does not mean the task succeeded. Exit 0 with no-verdict is not success. On Windows the run directory is handed to the child as C:/... (cygpath -m), never Git Bash's /tmp/..., which a native CLI reads as <drive>:\tmp.

Resume needs the session id from that run. Copy session-id and session.json into a new run directory, write a short continuation brief.md, and pass --resume-id. The auto-wait path does this itself once.