A0 Development

Agent Zero Development

Use this skill to develop Agent Zero or operate an existing instance on the user's behalf. For projects, chats, tasks, and other application features, read references/operate-agent-zero.md and use existing APIs. Load only the references needed for the task; verify current source before changing code.

Reality Rules

1. Source and nearest DOX beat memory, examples, and this skill if they disagree.
2. Before editing, read the applicable AGENTS.md chain from the repo root to every file you expect to touch.
3. New capabilities should usually be plugins. For plugin-specific work, load a0-create-plugin for authoring/review/contribution or a0-manage-plugin for discovery and lifecycle operations.
4. Do not assume ports. Discover WebUI host/port from startup output, launcher or Docker mapping, or explicit --host, --port, WEB_UI_HOST, and WEB_UI_PORT configuration.
5. In Docker, framework checks belong to /opt/venv-a0 and agent/user code execution belongs to /opt/venv. Do not use one runtime as proof for the other.
6. Treat /a0/ as the runtime framework root inside Docker. In local development it means the repository root. If a live container matters, prove that /a0 matches the checkout before trusting source-only conclusions.
7. Do not document or change ignored usr/ or tmp/ runtime state unless the user explicitly asks.

Reference Map

Load references with:

{"tool_name": "skills_tool:read_file", "tool_args": {"skill_name": "a0-development", "file_path": "references/<file>.md"}}

Working Flow

1. Distinguish operating existing features from developing new behavior. For application operations, follow references/operate-agent-zero.md; the remaining steps apply to source changes.
2. Read the root AGENTS.md, then the nearest child AGENTS.md files for the target paths.
3. Read the focused reference file from this skill.
4. Inspect the current source files named by the reference before making a claim or patch.
5. Keep changes narrow and in the repo-owned surface. Prefer usr/ for user-created runtime content, but do not document ignored user state unless requested.
6. Update DOX when a durable contract, path, behavior, workflow, responsibility, or verification rule changes.
7. Run targeted checks from the relevant DOX file. For skill-only changes, at minimum verify frontmatter parsing, reference paths, and markdown sanity.

Handoffs

• Plugin creation: load a0-create-plugin.
• Plugin management or installation: load a0-manage-plugin.
• Plugin review, debugging or publishing: load a0-create-plugin and read its relevant reference.
• Agent profile creation: load a0-create-agent.
• Skill creation or skill format work: load build-skill.

Closeout

Report the exact files changed, the grounding checks used, whether DOX was updated or intentionally left unchanged, and what verification ran. If a claim depends on a live Docker runtime, include the runtime proof, not only checkout evidence.