Antigravity agent is a Google DeepMind agent harness for local use and managed remote sandboxes through the Gemini API and Google AI Studio. A single Interactions API call can provision a secure, Google-hosted Linux sandbox identified by an environment ID, where the agent uses Gemini 3.8 Flash to plan, execute Bash, Python, and Node.js code, observe results, and repeat until the task is complete. It can install packages, run tests, build applications, manage files, search Google, fetch web pages, and call custom functions or remote MCP servers. The harness supports reusable skills, configurable tools, multi-turn interactions, streaming, automatic context compaction, persistent sandbox files, synchronous hooks for intercepting and validating code-execution and filesystem operations, and sources loaded from GitHub, Google Cloud Storage, or inline files. Managed environments provide a credential-injecting proxy and named agents, allowing the same workflow to run locally and in the cloud.