Borrowing it
Nothing to install: this file belongs to lessthanseventy/excessibility. 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/lessthanseventy/excessibility/main/AGENTS.mdgit clone --depth 1 https://github.com/lessthanseventy/excessibilityWrote 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/lessthanseventy/excessibility/agents-md)<a href="https://agentmods.dev/instructions/lessthanseventy/excessibility/agents-md"><img src="https://agentmods.dev/badge/instructions/lessthanseventy/excessibility/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/lessthanseventy/excessibility/agents-md"><img src="https://agentmods.dev/badge/instructions/lessthanseventy/excessibility/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 | $0.00714 | $0.00714 |
| Opus 5.5 | $0.00286 | $0.00286 |
| Sonnet 5.5 | $0.00143 | $0.00143 |
| Haiku 4.5 | $0.00071 | $0.00071 |
Grade A, and why
excessibility 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 13d 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 — 29 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Repository Guidelines
Project Structure & Module Organization
Elixir modules live in lib/, grouped by capability (excessibility/html, excessibility/system, etc.) and exposed through the Excessibility.* namespace. Assets needed for Pa11y and browser automation sit under assets/, including the vendored npm workspace. ExUnit tests live in test/, with HTML snapshots stored in test/excessibility/html_snapshots/ and approved baselines in test/excessibility/baseline/. Keep helper modules close to the code they exercise to simplify HexDocs generation and release reviews.
Build, Test, and Development Commands
mix deps.get && mix compile– fetch deps and verify the library still builds.mix igniter.install excessibility– apply the recommendedtest/test_helper.exsconfig and install Pa11y’s npm dependency insideassets/.mix test– run the suite;mix test test/source_test.exstargets a file while iterating.mix excessibilityandmix excessibility.approve– run Pa11y against snapshots, then promote.baddiffs intobaseline/.mix format && MIX_ENV=test mix credo --strict– enforce Quokka-backed formatting and linting before committing (Quokka takes its rules from.credo.exs;mix format --dot-formatter .formatter.agent.exs FILEformats one file without moving directives or lifting aliases).mix docs– regenerate HexDocs prior to publishing.
Coding Style & Naming Conventions
Favor idiomatic Elixir: two-space indentation, snake_case functions, PascalCase modules (e.g., Excessibility.SystemMock). Keep module files focused—public API modules wrap lower-level helpers. Run mix format to enforce .formatter.exs rules (Quokka plugin) and keep imports/aliases sorted. Snapshot filenames should read like MyModule/my_test/step.good.html so reviewers can trace origins quickly.
Testing Guidelines
Tests use ExUnit plus Mox; set expectations in test/test_helper.exs and call html_snapshot/4 (or related helpers) inside Conn, LiveView, or Wallaby cases. When snapshots change, inspect the .good/.bad pair, approve intentional diffs via mix excessibility.approve, and rerun mix test to ensure baselines match. Include regression tests whenever you add options to Excessibility.Snapshot or new mix tasks so Pa11y behavior stays predictable.
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.
- 13d ago Changed · +7 lines · +125 tokens per session a0123e372321
- 1mo ago First seen · 22 lines · 589 tokens per session scan A 27b5234fb1be
excessibility AGENTS.md is an instructions file published in the GitHub repository lessthanseventy/excessibility (42 stars, last pushed 13d ago), licensed MIT. It adds 714 tokens to every session, about $0.0029 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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