Borrowing it
Nothing to install: this file belongs to sergebulaev/facebook-skills. 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/sergebulaev/facebook-skills/main/CLAUDE.mdgit clone --depth 1 https://github.com/sergebulaev/facebook-skillsWrote 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/sergebulaev/facebook-skills/claude-md)<a href="https://agentmods.dev/instructions/sergebulaev/facebook-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/sergebulaev/facebook-skills/claude-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/sergebulaev/facebook-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/sergebulaev/facebook-skills/claude-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 | $0.02592 | $0.02592 |
| Opus 5.5 | $0.01037 | $0.01037 |
| Sonnet 5.5 | $0.00518 | $0.00518 |
| Haiku 4.5 | $0.00259 | $0.00259 |
Grade A, and why
facebook-skills CLAUDE.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 12d 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 — 167 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Project conventions - facebook-skills
This file is for any Claude Code agent working on this repository. Read it before making changes. Conventions here are mandatory unless the user asks otherwise.
Versioning
- Single source of truth:
.claude-plugin/plugin.json,.claude-plugin/marketplace.json,.codex-plugin/plugin.json, and.agents/plugins/marketplace.json. Plugin manifests must always match on package name and version; marketplace entries must point to the same package; author, license, homepage, and the public skill-bundle description must stay aligned. - Keep
CLAUDE.mdandAGENTS.mdaligned when changing shared project rules. Claude-specific workflow details belong here; Codex-specific details belong inAGENTS.md. - Codex marketplace install uses
.codex-marketplace/facebook-skills/. Do not edit that generated package by hand. Update the root files first, then runpython3 scripts/sync_codex_marketplace.py. - Default: bump the PATCH segment (3rd level,
0.0.X). This is the automatic behavior for every shippable commit, regardless of how large the diff feels. Skill renames, lib API breaks, new features: still PATCH by default. - Only bump MINOR or MAJOR when the user explicitly asks for a higher rank ("this is minor", "make it 2.0", "bump major"). Do not promote on your own initiative even if semver textbook says so.
- After bumping, two steps are required:
- Tag the commit:
git tag -a v<X.Y.Z> -m "..."+git push origin v<X.Y.Z> - Publish a GitHub Release for the tag:
gh release create v<X.Y.Z> --title "v<X.Y.Z>" --notes "<changelog>" --latestA tag alone does NOT update the README release badge. The shields.io badge reads from the Releases API, not from raw tags. Skipping step 2 leaves it stale.
- Tag the commit:
Commits
- Primary author must be Sergey: every
git commitneeds--author="Sergey Bulaev <[email protected]>". The harness defaults to the Claude identity if you forget; verify withgit log -1 --format='%an <%ae>'before pushing. - Co-author trailer (
Co-Authored-By: Claude ...) is fine and welcomed. - Verify locally before push: build never breaks, no broken refs in
SKILL.md, library smoke import passes.
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.
- 12d ago Changed · +30 lines · +620 tokens per session 2dde96957e89
- 1mo ago Changed · +2 lines · +44 tokens per session 2533f6679b73
- 1mo ago First seen · 135 lines · 1,928 tokens per session scan A 55b7bceebcd7
facebook-skills CLAUDE.md is an instructions file published in the GitHub repository sergebulaev/facebook-skills (71 stars, last pushed today), licensed MIT. It adds 2,592 tokens to every session, about $0.0104 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.
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.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.