chat-core 0.2.2

Core library for chat-rs
Documentation

chat-core

Core traits, types, and engine for chat-rs — the foundation every provider crate builds on. Exposes the Chat engine, ChatBuilder, the CompletionProvider / StreamProvider / EmbeddingsProvider traits, the Transport trait (with built-in HTTP/SSE and WebSocket impls), and the core message/tool/response types.

You usually don't depend on this crate directly — instead, depend on a provider crate (e.g. chat-openai, chat-gemini, chat-completions) which brings chat-core in transitively. Bring chat-core in explicitly when you want the engine types in your code without pulling the umbrella chat-rs crate.

Install

[dependencies]
chat-core = "0.2.2"

What's in here

  • builder::ChatBuilder — the type-state builder that wires a provider into a Chat engine
  • chat::Chat — the engine; orchestrates the call loop, tool calls, retries, HITL, structured output
  • traits — CompletionProvider, StreamProvider, EmbeddingsProvider, ChatProvider
  • transport — Transport trait + three built-in impls (feature-gated): ReqwestTransport (HTTP/SSE, default), AsyncWsTransport (tokio-tungstenite), WsTransport (tungstenite)
  • types — Messages, Content, Parts, Tool, ChatOptions, ChatResponse, StreamEvent, Metadata, etc.
  • error — ChatError, ChatFailure

Feature Flags

Feature What it enables
reqwest-transport HTTP/SSE transport via reqwest (default for most providers)
tokio-tungstenite Async WebSocket transport
tungstenite Sync WebSocket transport bridged via spawn_blocking
stream StreamProvider trait + streaming machinery
testing Test helpers for provider crates

Writing a Custom Provider

Implement CompletionProvider (and optionally StreamProvider, EmbeddingsProvider) on your client struct. Use the Transport abstraction so users can swap reqwest for their own HTTP/WS client. See providers/AGENTS.md for the conventions every existing provider follows.