Borrowing it
Nothing to install: this file belongs to Gfriend997/gemini-companion. 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/Gfriend997/gemini-companion/master/AGENTS.mdgit clone --depth 1 https://github.com/Gfriend997/gemini-companionWrote 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/instructions/gfriend997/gemini-companion/agents-md)<a href="https://agentmods.dev/instructions/gfriend997/gemini-companion/agents-md"><img src="https://agentmods.dev/badge/instructions/gfriend997/gemini-companion/agents-md/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/instructions/gfriend997/gemini-companion/agents-md"><img src="https://agentmods.dev/badge/instructions/gfriend997/gemini-companion/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00561 | $0.00561 |
| Opus 5.5 | $0.00224 | $0.00224 |
| Sonnet 5.5 | $0.00112 | $0.00112 |
| Haiku 4.5 | $0.00056 | $0.00056 |
Grade A, and why
gemini-companion AGENTS.md 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 29d 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 — 42 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent guide
Claude Code plugin delegating work to Google Gemini. Read this before changing anything.
Repo map
| Path | Purpose |
|---|---|
commands/*.md |
Slash command definitions — each runs one node scripts/gemini-companion.mjs <subcommand> call |
agents/gemini-rescue.md |
Subagent for delegated investigations/fixes |
skills/ |
Internal contracts: runtime invocation, prompt shaping, result handling |
prompts/ |
Prompt templates (review, adversarial-review) and the session routing policy |
hooks/hooks.json |
SessionStart: inject routing policy. Stop: optional review gate (off by default) |
scripts/gemini-companion.mjs |
Single runtime entry, stdlib only |
scripts/lib/ |
gemini.mjs (CLI spawns), jobs.mjs (background job state), image.mjs (REST image gen), ask.mjs (REST ask incl. media upload), scrub.mjs (secret masking) |
tests/ |
node --test suites for image, jobs, scrub |
docs/superpowers/ |
Design specs and plans — the decision record |
Non-negotiable invariants
GEMINI_API_KEYnever touches disk. No.env, no config files, no argv, no query params, no logs. CLI paths inherit it from the environment; image gen readsprocess.envat call time and sends it only as anx-goog-api-keyheader.- Prompts go to the CLI via stdin, never argv.
- Every write boundary passes through
scrub.mjs. New output paths must too. - Gemini output is untrusted. Relay verbatim; never auto-execute its suggestions.
- Read runs fail closed; only explicit
--writeruns get yolo approval.
Conventions
- Node stdlib only — no npm dependencies in the runtime.
- Windows-first but keep the POSIX branches working (
process.platform === "win32"splits ingemini.mjs,jobs.mjs). - New behavior gets a test in
tests/and, if user-visible, a README line. - Record significant design decisions in
docs/superpowers/specs/.
Verify
node --test "tests/*.test.mjs"
node -e "JSON.parse(require('fs').readFileSync('hooks/hooks.json','utf8'))"
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.
- 29d ago Changed · +13 tokens per session c7b73457835c
- 2mo ago First seen · 42 lines · 548 tokens per session scan A f5f0cbe6b73b
gemini-companion AGENTS.md is an instructions file published in the GitHub repository Gfriend997/gemini-companion (5 stars, last pushed 1mo ago), licensed MIT. It adds 561 tokens to every session, about $0.0022 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 2026-08-31.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
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Copilot instructions for denoland/deno, covering deno development guide for github copilot, network access, high level overview, key directories and key files to understand first.