Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/ericdrowell/brometal/agents-mdgit clone --depth 1 https://github.com/ericdrowell/brometalWhat 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 | $0.00953 | $0.00953 |
| Opus 5 | $0.00477 | $0.00477 |
| Sonnet 5 | $0.00191 | $0.00191 |
| Haiku 4.5 | $0.00095 | $0.00095 |
Grade A, and why
brometal 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 2d 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 — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.
BroMetal — notes for coding agents working on this repo
If you are writing an app that uses BroMetal, read
packages/brometal/AGENTS.md instead — it covers
the DSL rules and the failure modes. This file is about the codebase itself.
Layout
packages/brometal/ the library: compiler, runtimes, shader-function library
src/compiler/ parse → analyze → ir → optimize → emit-glsl / emit-wgsl
src/runtime/ context, program, uniforms, texture, render-target, loop
src/dsl/ the types and builtin stubs the DSL is written against
src/shader-functions/ library-source.ts (GPU source) + index.ts (typed decls)
src/geometries/ parametric mesh generators
tests/ vitest, no browser
packages/website/ Next.js site (brometal.dev): home, examples, SEO routes
src/shaders/ *.shader.ts + generated *.shader.gen.ts
src/demos/ one client component per example
Commands
npm test # vitest, from the repo root
npm run typecheck # both packages
npm run build # build the library (writes packages/brometal/dist)
npm run dev:website # site on :3005
# inside packages/website
npm run shaders # compile *.shader.ts with the LOCAL compiler
Use npm run shaders, not npx brometal. The website has a
brometal-published dependency (the released package, used to verify prod
builds), and npx brometal resolves to that — so your local compiler changes
appear to do nothing. npm run shaders points at ../brometal/dist.
Rebuild the library before recompiling website shaders. The CLI runs from
dist, so a change to src/compiler needs npm run build first.
Adding a shader function
Two files, kept in step:
src/shader-functions/library-source.ts— the GPU source, as a string, with adepsarray naming any other library functions it calls. Dependencies are pulled in automatically and tree-shaken if unused.src/shader-functions/index.ts— the typed declaration plus agpuOnly(...)body, so calling it on the CPU throws with a useful message.
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.
- 2d ago First seen · 85 lines · 953 tokens per session scan A d89d2918413b
brometal AGENTS.md is an instructions file published in the GitHub repository ericdrowell/brometal (104 stars, last pushed 16d ago), licensed MIT. It adds 953 tokens to every session, about $0.0048 per session on Opus 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.
Other instructions, from other repositories
oxc AGENTS.md
Instructions for oxc-project/oxc, covering agents.md - ai assistant guide for oxc, ai usage policy for contributors, repository structure, core crates and development commands.
compiler-explorer AGENTS.md
Instructions for compiler-explorer/compiler-explorer, covering agents.md, build & test commands, important workflow requirements, style guidelines and architecture guidelines.
oxc copilot-instructions.md
Instructions for oxc-project/oxc: When reviewing pull requests in this repository.
compiler-explorer copilot-instructions.md
Instructions for compiler-explorer/compiler-explorer: For each answer to the user, evaluate your level of confidence in the correctness of the answer on a scale from 1 to 10, where 1 is very uncertain and 10 is absolutely certain. If your confidence level is below 8, state so and suggest ways to verify the answer.
grida AGENTS.md
Instructions for gridaco/grida, covering hi robots, welcome to the grida project, project structure, languages, frameworks, tools, infrastructures, documentation and the rust engine — moved to gridaco/nothing.
neva AGENTS.md
AGENTS.md instructions for nevalang/neva, covering neva engineering guide, project model, repository map, documentation and ai engineering harness.