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/ljchang/mecha/agents-mdgit clone --depth 1 https://github.com/ljchang/mechaWhat 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 | $0.01333 | $0.01333 |
| Opus 5 | $0.00666 | $0.00666 |
| Sonnet 5 | $0.00267 | $0.00267 |
| Haiku 4.5 | $0.00133 | $0.00133 |
Grade A, and why
mecha 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 — 129 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
Instructions for AI coding agents working in this repository.
Read CLAUDE.md first, in full. It holds the cross-cutting
invariants any session needs on any run, and this file deliberately does not
duplicate it. docs/ARCHITECTURE.md records why
each subsystem is shaped the way it is — the incident behind each invariant,
and the bug that reappears when one is undone; read its section before
changing a subsystem. That reasoning is what you need in order to change
something safely, and it is not recoverable from the code alone.
CONTRIBUTING.md covers build commands, the testing layers,
and pull request expectations.
Orientation
mecha-core/ the library; knows nothing about any CLI or application
mecha-cli/ the `mecha` binary; thin, all logic belongs in core
mecha-mail/ library plus three MCP binaries for mail and calendar
mecha-slack/ the Slack transport; has no mecha-core dependency, and must
never gain one — that is why it is a crate and not a module
eval/ the case set and its fixtures
website/ the Docusaurus documentation site
docs/ design and research notes, not user documentation
results/ recorded scorecards; the baselines comparisons are made against
Four workspace members, all published to crates.io. A new one that anything published depends on must be added to the release workflow's publish list in the same change that introduces it.
Before you start
cargo build --workspace --all-targets
cargo test --workspace
Both should pass on a clean checkout. If they do not, fix that before making changes — you cannot tell your breakage from pre-existing breakage otherwise.
Before you finish
cargo fmt --all
cargo clippy --all-targets --all-features
cargo test --workspace
CI treats warnings as errors, so a clippy warning will fail the build.
The traps
Each of these is a real bug this project has already shipped once. They share a shape: the code compiles, every test stays green, and the failure appears somewhere else entirely.
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 · 129 lines · 1,333 tokens per session scan A 47634197ed9c
mecha AGENTS.md is an instructions file published in the GitHub repository ljchang/mecha (6 stars, last pushed 2d ago), licensed MIT. It adds 1,333 tokens to every session, about $0.0067 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 2026-08-31.
Other instructions, from other repositories
agent-framework copilot-instructions.md
Instructions for microsoft/agent-framework, covering github copilot instructions, repository structure and architectural decision records (adrs).
HARTOS CLAUDE.md
Instructions for hertz-ai/HARTOS, covering claude.md, project overview, master key - ai exclusion zone, branch discipline — main branch only (mandatory) and sibling repos — canonical filesystem paths.
orloj AGENTS.md
Instructions for OrlojHQ/orloj, covering orloj agent instructions, must-follow sync rules and working style.
orloj CLAUDE.md
Instructions for OrlojHQ/orloj, covering orloj claude instructions, critical repository rules and implementation notes.
Framework_Development_Guide
Instructions for rezaho/MARSYS, covering 0. golden principle, 1. layered architecture (mental model), 2. core classes & responsibilities, 2.1 module overview & logical flow and src/agents/ - agent architecture & communication.
rn-dev-agent AGENTS.md
Instructions for Lykhoyda/rn-dev-agent, covering repository guide for agents, repository map, editing rules, architecture rules and supported node runtimes.