google-antigravity-sdk-dart

name	google-antigravity-sdk-dart
description	Initialize, configure, or debug Google Antigravity (AGY) agents, custom tools, persona configs, and subagents in Dart.

Google Antigravity SDK for Dart

1. Execution Steps

1. Dependency Verification: Verify antigravity dependency in pubspec.yaml.
2. Key & Service Tier Lookup: Pass GEMINI_API_KEY via LocalAgentConfig(apiKey: "...") or ensure the GEMINI_API_KEY environment variable is set. Optionally specify ServiceTier.priority for prioritized inference.
3. Session Initialization: Configure LocalAgentConfig with default generative text model gemini-3.7-flash, execution behavior AgentBehavior.autonomous, required tool lists, persona system instructions, budget configuration (BudgetConfig), and policy rules before launching the agent instance.

2. Standard Example References

Reference implementations for common setups:

• hello_world.dart: Basic agent session initialization.
• custom_tools.dart: Custom tool handler registration.
• persona_config.dart: System instruction and persona setup.
• structured_output.dart: Structured JSON schema response parsing.
• cancellation.dart: Session turn cancellation via response.cancel().
• budget_limits.dart: Session budget controls and stop reason inspection.
• subagents.dart: Dynamic delegation, static subagents, and nested subagent hierarchies.
• agent_skills.dart: Dynamic skill loading and registration.

Completion Criteria

• antigravity dependency is resolved in pubspec.yaml.
• GEMINI_API_KEY is validated in config or environment.
• Agent session initializes and executes prompt turn without throw.
• Turn cancellation via response.cancel() or agent.conversation.cancel() terminates active trajectory gracefully when invoked.