bf59b7e23d
Adds a chat_completions route module to litellm-core, mirroring the messages route, plus Anthropic Messages and Bedrock Converse provider configs. The per-model `rust: true` opt-in now covers /chat/completions for both providers. The core accepts an allowlisted subset (text conversations, non-streaming) and returns CoreError::Unsupported for anything else, so tool calls, multimodal content and streaming fall back to the Python path transparently. Resolves LIT-5698 |
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|---|---|---|
| .. | ||
| crates | ||
| .gitignore | ||
| ADDING_A_PROVIDER.md | ||
| AGENTS.md | ||
| Cargo.lock | ||
| Cargo.toml | ||
| CLAUDE.md | ||
| README.md | ||
LiteLLM Rust
This workspace contains the staged Rust implementation for LiteLLM.
litellm-core is the LiteLLM SDK in Rust: one entrypoint per top-level call
that makes the LLM call and hands back a typed response, the same shape as
litellm.messages() in Python.
let response = litellm_core::messages::messages(MessagesRequest {
model: "claude-sonnet-4-5",
body,
api_key: Some(key),
..
})
.await?;
Python continues to own configuration, retries, routing policy, logging, callbacks, spend tracking, and customer plugins until each Rust path has parity coverage and production evidence.
Crates
| Crate | Role |
|---|---|
| litellm-core | The SDK. Per-route entrypoints (messages::messages()), types, provider transforms (modules under providers/), provider resolution, auth, the provider HTTP call, and the router. |
| litellm-ai-gateway | The axum server (behind the server feature) and WebSocket hosts. Translates HTTP/WS to core entrypoints; no provider handlers. |
| litellm-python-bridge | PyO3 cdylib exposing Rust to the litellm Python SDK — marshals Python objects and calls core entrypoints. |
Dependency direction (acyclic): litellm-core ← litellm-ai-gateway ← litellm-python-bridge.
Layout
crates/
core/ The SDK: route modules + provider transforms.
src/messages/ mod.rs (entrypoint), types, transformation, prepare, handler, client
src/providers/anthropic/messages/transformation.rs
ai-gateway/ Axum server + WebSocket hosts; calls core entrypoints.
python-bridge/ PyO3 bridge for Python LiteLLM.
The folder shape follows the Python provider tree:
core/src/providers/<provider>/<route>/transformation.rs. The bridge exposes one
function per top-level route, mirroring the core entrypoints.
Checks
Run these before pushing Rust changes. GitHub Actions runs the same checks for
changes under litellm-rust/.
cargo fmt --check
cargo clippy --workspace --all-targets -- -D warnings
cargo test --workspace