# Leon Coding Agent

Investigates, implements, and verifies code changes in a repo with file and shell tools.

- Repository: https://github.com/leon-ai/leon (17626 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add leon-ai/leon --skill coding -g -a claude-code -y`
Codex: `npx skills add leon-ai/leon --skill coding -g -a codex -y`
Cursor: `npx skills add leon-ai/leon --skill coding -g -a cursor -y`
Gemini CLI: `npx skills add leon-ai/leon --skill coding -g -a gemini-cli -y`

## Description

Investigate, implement and verify code changes directly in a repository using Leon's file, search and shell tools.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Coding

Code directly with Leon's existing loop and tools. Respect scope: analysis does not authorize edits, commits, pushes or publication. Delegate only on owner request or applicable preference.

For delegation, use the owner's preferred available agent/interface. Pass the repository, task, instructions and authorized scope; inspect and verify results, not just prompt submission. If unavailable, explain briefly and continue directly within scope.

## Repository and instructions

1. Establish the exact workspace/cwd from the request and live observations. Read relevant manifests and nearby code; reuse helpers before adding abstractions.
2. Before project commands or edits, inspect applicable `AGENTS.md` files from repository root through each target directory. `file.read` includes them in `repositoryInstructions` with source reads; read missing instructions explicitly. Confirm full returned text, since shell success alone does not prove a file was read. Reuse complete returned instructions, including unchanged content referenced in earlier visible tool results, instead of rediscovering the same files. Apply their package manager and test commands to the baseline as well as final checks. Deeper rules override broader ones only in their subtree. For non-Git work, use the owner-selected boundary, excluding unrelated parent instructions.
3. In plan details, record workspace, instruction paths, constraints, and acceptance criteria with required checks from the request/references. Discover nested instructions before editing new directories. After compaction/continuation, reread applicable files in full before editing; summaries cannot replace current instructions.
4. Inspect Git status and staged/unstaged diffs; record and preserve unrelated changed/untracked content. Never reset, clean, stage or commit owner work without authorization. Use an isolated worktree when concurrency or the requested workflow warrants it.

## Investigate and change

The rest: https://github.com/leon-ai/leon/blob/HEAD/skills/agent/coding/SKILL.md