Google Antigravity v0.1.5

0.1.5 June 25, 2026 Streaming tool calls, custom subagent delegates, and thread safety enhancements This release introduces native OpenTelemetry tracing support, declarative subagent configurations, improved type safety, and critical robustness and compatibility updates. Improvements (5) OpenTelemetry Tracing Support : Integrates OpenTelemetry tracing into the SDK to translate session, turn, step, and tool lifecycle events into standard GenAI-compliant semantic spans for advanced monitoring and performance debugging, with custom task-safe active span propagation for tool execution. Declarative Subagent Configurations : Added SubagentConfig and SubagentCapabilities in types.py to support constructing static subagents with declarative instructions and tools directly. Type Safety in AgentConfig : Type-annotated policies, hooks, and triggers parameters on AgentConfig and its subclasses to improve type safety and overall developer experience. Lifecycle Hook Routing : Shifted core orchestration of OnSessionStartHook , turn-level hooks ( PRE_TURN and POST_TURN ), and OnSessionEndHook to the connection layer, implementing the Python-side HookRouter for event routing. Public API Cleanup : Hid internal validation methods on media and error classes by prefixing them with an underscore ( _validate_mime_type and _from_pydantic on validation errors). Fixes (2) Historical Step Absorption : Ensured historical step absorption is properly drained during initialization to prevent persistence non-linearity issues in Conversation . Python 3.14 Compatibility : Resolved potential name shadowing in the Conversation class by renaming the top-level connection module import. Patches (0) 0.1.4 June 18, 2026 Async tool execution buffers, memory state persistence, and error handling improvements This release introduces major architectural refactorings, public API standardizations, and key new capabilities centered on centralizing model configurations to natively support multi-model backends, exp