# Google Antigravity Blog: Introducing Custom Agents

Custom agents are Markdown files with YAML frontmatter that can run as main agents or subagents, with scoped command policies and nested lifecycle hooks.

- Custom agents are defined as Markdown files with YAML frontmatter and stored under .agents/agents/ or ~/.gemini/config/agents/.
- Project-specific agents committed to a repository automatically become available to every teammate who checks it out.
- An agent can run as a main agent selected in the GUI or via jetski --agent, or be delegated to as a subagent.
- commandExecutionPolicy: auto lets agents run standard test and compile commands autonomously while high-risk commands stay gated.
- Lifecycle hooks can run setup scripts before invocation and verify the local environment before specific tool use.

## Why it matters

Developers using Antigravity can now define reusable specialized agents with scoped instructions, safety policies, and hooks, reducing context bloat and standardizing team workflows.

## Sources

- [Antigravity: Google Antigravity Blog: Introducing Custom Agents](https://antigravity.google/blog/introducing-custom-agents)

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Summarized by dstilled on 2026-08-12. https://dstilled.ai/story/79a69891-d8b6-482b-bdd8-633a9bcf9a95