flutter_agent_harness

flutter_agent_harness is a pure-Dart agent core, with no dependency on dart:io or Flutter in its library code, so the same agent loop compiles and runs on the Dart VM, Flutter desktop and mobile apps, and the web, with platform-specific capabilities kept behind an execution-environment abstraction. Provider failures never throw; every error, including network failures, rate limits and malformed streaming data, arrives as a typed error event so the agent loop keeps running instead of dying on a dropped connection.

It supports each provider's native tool-calling format, including OpenAI's tools, Anthropic's tool use and Google's function calling, with prompt-based tool calling available only as an opt-in adapter for chat-only runtimes, plus token-based context accounting, model-role fallback chains, API-key rotation and cancellation support throughout. Sessions are stored as append-only JSONL trees supporting branching and labeled navigation, and the project ships a terminal coding agent built on the same core, with a web demo, an iOS beta and a macOS app.