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/fellipeutaka/leon/agents-mdgit clone --depth 1 https://github.com/fellipeutaka/leonWhat 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 | $0.00308 | $0.00308 |
| Opus 5 | $0.00154 | $0.00154 |
| Sonnet 5 | $0.00062 | $0.00062 |
| Haiku 4.5 | $0.00031 | $0.00031 |
Grade A, and why
leon 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.
What it actually says
Leon — Agent Skills Collection
Curated collection of Agent Skills for AI coding agents.
Project Structure
skills/— all skills (original and synced from upstream)scripts/sync-upstream.ts— syncs skills from external repos via GitHub APIupstream.json— manifest tracking which skills come from external repos, their source SHA and last sync timestamp
Skills Format
Each skill is a directory inside skills/ following the Agent Skills format:
SKILL.md(required) — skill definition with YAML frontmatter (name,description)README.md— user-facing documentationscripts/— helper scripts (optional)references/— supporting docs (optional)
Upstream Skills
Some skills are synced from external repos. Tracked in upstream.json.
- Sync all:
bun sync - Sync new only:
bun sync --new-only(skips skills that already have alastSync) - Synced skills can be locally modified — just know re-syncing overwrites local changes
- Set
GITHUB_TOKENenv var to avoid API rate limits
Tech Stack
- Bun + TypeScript
- No external dependencies
Conventions
- Skill directory names use kebab-case
- SKILL.md frontmatter must have
nameanddescriptionfields - Keep skills self-contained — no cross-skill dependencies
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 · 39 lines · 308 tokens per session scan A ea04fc21146a
leon AGENTS.md is an instructions file published in the GitHub repository fellipeutaka/leon (5 stars, last pushed 4d ago), licensed MIT. It adds 308 tokens to every session, about $0.0015 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
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).
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
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 oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.