Ruler is a tool that keeps coding-agent instructions in one central location and distributes them into the configuration files used by supported agents. Teams use it to apply consistent, context-specific guidance across tools such as Copilot, Claude, Cursor, and Aider. The catalogue entries provide an instruction and MCP configuration for using Ruler.
Borrowing it
Nothing to install: this file belongs to intellectronica/ruler. 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/intellectronica/ruler/main/AGENTS.mdgit clone --depth 1 https://github.com/intellectronica/rulerWrote 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/intellectronica/ruler/agents-md)<a href="https://agentmods.dev/instructions/intellectronica/ruler/agents-md"><img src="https://agentmods.dev/badge/instructions/intellectronica/ruler/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/intellectronica/ruler/agents-md"><img src="https://agentmods.dev/badge/instructions/intellectronica/ruler/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 | $0.00279 | $0.00279 |
| Opus 5.5 | $0.00112 | $0.00112 |
| Sonnet 5.5 | $0.00056 | $0.00056 |
| Haiku 4.5 | $0.00028 | $0.00028 |
Grade A, and why
ruler 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 1mo 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.
What it actually says
Ruler
Development Process
Testing
- Always follow TDD where possible - first adding or adjusting tests, verifying that they fail, then making the minimal changes to pass the tests.
- Everything in this repository should be covered by tests. That always includes:
- Unit tests
- Integration tests
- End-to-end tests
Code Formatting
- Always ensure that the code is formatted correctly by running prettier before committing changes.
Branches and Pull Requests
- Unless specifically instructed otherwise, all changes should be made in a feature branch and submitted as a pull request for review.
- Pull requests should be descriptive and clearly explain the changes being made, including the rationale behind the change, the functional changes, the specific files and modules affected.
- Before declaring a pull request ready for review, you must ensure that all the CI tests pass. These include:
npm cinpm run lintnpm testnpm run build
- IMPORTANT: Before committing, always use Prettier to ensure that the code is formatted correctly.
- IMPORTANT: When committing yourself with
git commit, always pass--author="AI <[email protected]>"so that your commits can be easily identified.
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.
- 1mo ago First seen · 33 lines · 279 tokens per session scan A 010293e2b4b1
ruler AGENTS.md is an instructions file published in the GitHub repository intellectronica/ruler (2,952 stars, last pushed 5d ago), licensed MIT. It adds 279 tokens to every session, about $0.0011 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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