firstmate is an agent distribution that lets one coding agent coordinate a crew of autonomous agents working in separate git worktrees. It is for running parallel fixes, investigations, plans, and audits while receiving completed pull requests, merges, or reports through one supervising agent. The catalogue entries provide skills, hooks, instructions, and settings for operating this workflow.
Borrowing it
Nothing to install: this file belongs to kunchenguid/firstmate. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/kunchenguid/firstmate/main/.agents/skills/firstmate-codexapp/SKILL.mdgit clone --depth 1 https://github.com/kunchenguid/firstmateWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/kunchenguid/firstmate/firstmate-codexapp)<a href="https://agentmods.dev/skills/kunchenguid/firstmate/firstmate-codexapp"><img src="https://agentmods.dev/badge/skills/kunchenguid/firstmate/firstmate-codexapp/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/kunchenguid/firstmate/firstmate-codexapp"><img src="https://agentmods.dev/badge/skills/kunchenguid/firstmate/firstmate-codexapp.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00048 | $0.01182 |
| Opus 5.5 | $0.00019 | $0.00473 |
| Sonnet 5.5 | $0.00010 | $0.00236 |
| Haiku 4.5 | $0.00005 | $0.00118 |
Grade A, and why
firstmate-codexapp scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 110 lines — stays where its author put it; the contents beside it link to each section on GitHub.
firstmate-codexapp
Overview
Use this playbook when Firstmate work needs a visible Codex Desktop thread.
The current supported shape is Desktop host-tool choreography plus an explicit status-file return-channel check, not a codex-app value in FM_BACKEND.
Boundary
Codex Desktop visible threads are companion host-tool workflows, not a selectable Firstmate backend.
Read docs/codex-app-backend.md when it exists in this checkout; that document owns the acceptance contract, bridge requirement, status-return requirement, and staged rollout.
If local helper scripts exist for Codex App work, use only helpers explicitly provided by the operator or maintained by Firstmate.
For helpers outside bin/, inspect the source or header before running --help.
Preflight
- Confirm this session is running inside Codex Desktop and that the host tools are exposed.
Search exact names when needed:
create_thread,list_threads,read_thread,send_message_to_thread,archive, andset_thread_archived. - Confirm the target repository is already saved as a Codex Desktop project. No host tool currently creates Codex App projects for an agent, so the human must add the project in Desktop before a created thread can reliably land there.
- Do not create projectless threads for repo work. If the project is absent, stop and ask for the project to be added or use a normal Firstmate backend instead.
- Decide whether this is a real Firstmate-managed task or a visible companion thread.
A real task needs a task id, an isolated worktree or Desktop-owned cwd, a branch plan, and a writable
state/<id>.statuspath.
Create And Send
When creating a visible thread, use the Desktop host tool, not shell imitation. Target the saved project and ask the worker to start by reporting:
pwd
git rev-parse --show-toplevel
git branch --show-current
git log --oneline --max-count=3
For writable repo work, instruct the worker to use the Codex-created current directory.
Do not tell it to cd into the saved project checkout for edits, commits, no-mistakes, pushes, or PR work.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 4d ago Changed · -1 lines · -23 tokens per session fde64b94f7ff
- 28d ago Changed 3926001a9c43
- 1mo ago First seen · 111 lines · 71 tokens per session scan A f2110451ea8a
firstmate-codexapp is a skill published in the GitHub repository kunchenguid/firstmate (8,295 stars, last pushed today), licensed MIT. It adds 48 tokens to every session and 1,182 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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