litellm-rs

A high-performance Rust library and gateway for calling 100+ LLM APIs in an OpenAI-compatible format.

Features

• 100+ AI Providers - OpenAI, Anthropic, Google, Azure, AWS Bedrock, and more
• OpenAI-Compatible API - Drop-in replacement for OpenAI SDK
• High Performance - 10,000+ requests/second, <10ms routing overhead
• Intelligent Routing - Load balancing, failover, cost optimization
• Enterprise Ready - Auth, rate limiting, caching, observability

Quick Start (5 Minutes, API-Only Recommended)

Most users use this project as a unified API library, not as a gateway server. Start with API-only mode first.

[dependencies]
litellm-rs = { version = "0.4", default-features = false, features = ["lite"] }

For crate users, no make is required.

Usage

As a Library (API Integration)

use litellm_rs::{completion, user_message, system_message};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let response = completion(
        "gpt-4",
        vec![
            system_message("You are a helpful assistant."),
            user_message("Hello!"),
        ],
        None,
    ).await?;

    println!("{}", response.choices[0].message.content.as_ref().unwrap());
    Ok(())
}

As a Gateway Server

Run from source repository

git clone https://github.com/majiayu000/litellm-rs.git
cd litellm-rs
cp config/gateway.yaml.example config/gateway.yaml
cargo run --bin gateway

Install binary and run

cargo install litellm-rs --bin gateway
mkdir -p config
curl -L https://raw.githubusercontent.com/majiayu000/litellm-rs/main/config/gateway.yaml.example -o config/gateway.yaml
gateway

Notes:

• gateway and google-gateway binaries require storage feature at build time.
• Default features include sqlite, so default cargo run/cargo install satisfy this requirement.

Installation

# Full gateway with SQLite + Redis (default)
[dependencies]
litellm-rs = "0.4"

# API-only - lightweight, no actix-web/argon2/aes-gcm/clap
[dependencies]
litellm-rs = { version = "0.4", default-features = false }

# API-only with metrics
[dependencies]
litellm-rs = { version = "0.4", default-features = false, features = ["lite"] }

# Gateway modules in library context (not standalone gateway binary runtime)
[dependencies]
litellm-rs = { version = "0.4", default-features = false, features = ["gateway"] }

Supported Providers

Environment Variables

# Provider API Keys
OPENAI_API_KEY=sk-...
ANTHROPIC_API_KEY=sk-ant-...
GOOGLE_API_KEY=...
AZURE_OPENAI_API_KEY=...
AWS_ACCESS_KEY_ID=...
AWS_SECRET_ACCESS_KEY=...
GROQ_API_KEY=...
DEEPSEEK_API_KEY=...
MOONSHOT_API_KEY=...
ZHIPU_API_KEY=...
MINIMAX_API_KEY=...

# Optional
LITELLM_VERBOSE=true  # Enable verbose logging

Examples

Multi-Provider Routing

use litellm_rs::{completion, user_message};

// Automatically routes to the right provider based on model name
let openai = completion("gpt-4", vec![user_message("Hi")], None).await?;
let anthropic = completion("anthropic/claude-3-opus", vec![user_message("Hi")], None).await?;
let google = completion("gemini/gemini-pro", vec![user_message("Hi")], None).await?;
let bedrock = completion(
    "bedrock/us.anthropic.claude-3-5-sonnet-20241022-v2:0",
    vec![user_message("Hi")],
    None,
)
.await?;

Embeddings

use litellm_rs::{embedding, embed_text};

// Single text
let embedding = embed_text("text-embedding-3-small", "Hello world").await?;

// Batch
let embeddings = embedding(
    "text-embedding-3-small",
    vec!["Hello", "World"],
    None,
).await?;

Streaming

use litellm_rs::{completion_stream, user_message};
use futures::StreamExt;

let mut stream = completion_stream(
    "gpt-4",
    vec![user_message("Tell me a story")],
    None,
).await?;

while let Some(chunk) = stream.next().await {
    if let Ok(chunk) = chunk {
        print!("{}", chunk.choices[0].delta.content.unwrap_or_default());
    }
}

Performance

• Throughput: 10,000+ requests/second
• Latency: <10ms routing overhead
• Memory: ~50MB base footprint
• Concurrency: Fully async with Tokio

Troubleshooting

Build/test uses too much CPU or memory

• Use API-only defaults first: cargo test --lib --tests --no-default-features --features "lite"
• Limit local parallelism when needed: CARGO_BUILD_JOBS=4 cargo test --lib --tests --no-default-features --features "lite" -- --test-threads=4
• Avoid --all-features unless you are doing release/nightly validation

I only need provider API aggregation, not gateway

• Prefer default-features = false with features = ["lite"]
• Use gateway runtime commands only when you need HTTP server/auth/storage middleware

Documentation

• API Documentation
• Documentation Index
• Configuration Guide
• Examples

Contributing

See CONTRIBUTING.md for development setup and guidelines.

Security

See SECURITY.md for security policy and vulnerability reporting.

License

MIT License - see LICENSE for details.

Acknowledgments

Inspired by LiteLLM (Python).