antigravity-multimodal-state-dart

name	antigravity-multimodal-state-dart
description	Manage thread-safe state using StateStore, persist sessions via SessionContinuationMode, or handle multimodal payloads in Dart.

StateStore, Session Continuation & Multimodal Payloads in Dart

Guidelines for managing context state hierarchies, persisting agent sessions across application runs, and constructing multimodal input payloads.

1. Thread-Safe State Management & Session Continuation

1. State Store Hierarchy: Store and query shared context metadata across tools and hooks using StateStore with concurrent reentrancy locking.
2. Session Continuation: Configure SessionContinuationMode in LocalAgentConfig:
   • SessionContinuationMode.resume: Awaits and resumes an existing session ID.
   • SessionContinuationMode.createOrResume: Resumes session if available; creates new session otherwise.
   • SessionContinuationMode.createOnly: Forces fresh session creation.

For code examples, inspect references/state_multimodal_patterns.md.

2. Multimodal Payload Construction & Token Telemetry

• Media Buffers: Construct MediaContent from binary bytes (Uint8List), file paths (fromFile), with automatic MIME type detection.
• Token Usage Arithmetic: Stream live UsageUpdate events and compute trajectory token balances using UsageMetadata addition (+) and subtraction (-) operators.

For implementations, read references/state_multimodal_patterns.md.

Completion Criteria

• State mutations use StateStore or context.set() safely.
• SessionContinuationMode is declared explicitly when resuming persistent sessions.
• Multimodal attachments specify supported MIME types (image/png, audio/mp4, application/pdf).