* feat(router): add Switchyard Stage Router strategy * feat(router): decision-model classifier and safer fallbacks for the Switchyard stage router Moves to nemo-switchyard 0.4.0a1, which adds decision-model classifiers and makes ModelCall.respond and fail async. The classifier is now a tagged union of an LLM judge and a decision model, and decision calls go through the router's adecisions so any decisions provider works. Algorithm misbehavior and library errors route to the capable model instead of failing the request, and the session id plus client session headers are always passed so capable holds apply without a classifier Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * fix(router): keep the Switchyard router inside the type-check gate The gate's environment did not install the optional switchyard extra, so every libsy symbol counted as Unknown. nemo-switchyard joins proxy-dev like the other optional runtime packages, and imports go through switchyard_rust.libsy, which ships py.typed. Step handling moves into helpers so no Final is rebound in the loop, and the dashboard API types are regenerated for the new routing fields Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * fix(router): route Switchyard on every endpoint and reject unsafe router saves The router now passes each request's call type to routing strategies, and Switchyard converts the request to chat messages with the existing converter for that call type before translating it. /v1/messages turns with tool or thinking blocks used to fall back to the capable model, and now route on their signals. The Anthropic converter can keep tool_result.is_error on an analysis copy, so Switchyard sees tool failures there, while requests sent to models never carry it Saves of a strategy router that lists itself now fail with a 400 instead of a 500 with a dead row, the capable and efficient models must differ, judge and decision calls are not retried before failing open, the Switchyard routing fields are classified for redaction, and the edit dialog returns the saved router instead of the stale one Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * fix(router): catch self-routing on patch and rename, and trim Switchyard tests The self-routing check now reads the stored params through the decrypting helper and runs when a patch carries no litellm_params, so a PATCH that points a router at itself or renames it onto one of its targets returns 400 instead of a 500 with a dead row. The Switchyard tests share one transcript builder and router fixture, and reformatting noise in unrelated test files is reverted Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * refactor(ui): make Switchyard a strategy in the existing auto router form Switchyard is now a card in the existing strategy picker. Picking it swaps the tier and classifier fields for the Switchyard fields, and the shared name, team and save button create it through one submit branch, the same flow as the other strategies. The separate add form, the extracted picker and the hidden-form swap are gone, and the edit dialog keeps its own Switchyard form The judge's session_affinity and message_hash_fallback settings are removed, since Switchyard rejects both for the stage router Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * fix(ui): accept partial tool semantics and show server errors on model edit The Switchyard tool semantics field rejected mappings that list only some categories, although the server accepts them. Model PATCH errors were reduced to a generic message, so it now goes through the shared API client like model create and surfaces the server text Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * feat(ui): show the routing strategy picker up front in the auto router form Every strategy was hidden behind an Advanced configuration link, so the quick setup read as the only option and never said it creates a heuristic router. The picker now always shows with Heuristics as the labelled default, the quick setup sits under it, and picking another strategy opens that strategy prefilled with the chosen models Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * fix(ui): show the server's reason when a model settings or API key update fails Both screens replaced the rejection with a fixed message, so a 400 such as a router routing to itself read only as a generic failure Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * feat(router): route Switchyard on the Rust router core main replaced the Python router core with the Rust one, which left Switchyard routers registered nowhere. Register them with the other pre-routing strategies, hand each strategy the endpoint the request came through, and evict Switchyard routers on reload and delete like the rest Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * fix(router): scope Switchyard sessions per API key and fix review gaps in the Switchyard form Switchyard session state is keyed by a hash of the caller's key hash and session id, and client session headers no longer reach Switchyard unscoped. The add form carries the quick setup models into Switchyard, sends the team and access groups, clears a stale tool semantics error, and the schema reads API-saved configs with nulls and structured decision instructions Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * test(router): make the Switchyard test folder a package * fix(router): read the Switchyard session key hash only from the proxy's own metadata * fix(proxy): keep nested nulls as null when masking deployment params * fix(router): send Switchyard judge calls with the caller's own metadata bucket so tag routing applies * fix(router): put Switchyard judge metadata in the bucket the judge endpoint reads --------- Co-authored-by: Joshua Valluru <326636767+joshua-berri@users.noreply.github.com> Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com> |
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| .agents/skills/database-access | ||
| .cargo | ||
| .circleci | ||
| .devcontainer | ||
| .githooks | ||
| .github | ||
| .semgrep/rules | ||
| backend | ||
| ci_cd | ||
| cookbook | ||
| db_scripts | ||
| docker | ||
| docs/adrs | ||
| enterprise | ||
| examples | ||
| gateway | ||
| helm | ||
| litellm | ||
| litellm-proxy-extras | ||
| litellm-rust | ||
| litellm_cli | ||
| migrations | ||
| packaging | ||
| scripts | ||
| skills/litellm-setup | ||
| terraform | ||
| tests | ||
| ui | ||
| vscode-extension | ||
| .dockerignore | ||
| .env.example | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitguardian.yaml | ||
| .gitignore | ||
| .grype.yaml | ||
| .npmrc | ||
| AGENTS.md | ||
| ARCHITECTURE.md | ||
| codecov.yaml | ||
| CONTRIBUTING.md | ||
| cosign.pub | ||
| docker-compose.hardened.yml | ||
| docker-compose.liteadmin.yml | ||
| docker-compose.yml | ||
| Dockerfile | ||
| GEMINI.md | ||
| LICENSE | ||
| license_cache.json | ||
| Makefile | ||
| mcp_servers.json | ||
| model_prices_and_context_window.json | ||
| osv-scanner.toml | ||
| package-lock.json | ||
| package.json | ||
| policy_templates.json | ||
| prometheus.yml | ||
| provider_endpoints_support.json | ||
| proxy_server_config.yaml | ||
| pyproject.toml | ||
| pyrightconfig.json | ||
| qa_sticky_session.sh | ||
| README.md | ||
| render.yaml | ||
| router_plugins.json | ||
| ruff-strict.toml | ||
| ruff-tests.toml | ||
| ruff.toml | ||
| rust-toolchain.toml | ||
| schema.prisma | ||
| SECURITY.md | ||
| taplo.toml | ||
| uv.lock | ||
| whitelisted_bedrock_models.txt | ||
🚅 LiteLLM
LiteLLM AI Gateway
Open Source AI Gateway for 100+ LLMs. Self-hosted. Enterprise-ready. Call any LLM in OpenAI format.
LiteLLM Proxy Server (AI Gateway) | Hosted Proxy | Enterprise Tier | Website
What is LiteLLM
LiteLLM is an open source AI Gateway that gives you a single, unified interface to call 100+ LLM providers — OpenAI, Anthropic, Gemini, Bedrock, Azure, and more — using the OpenAI format.
Use it as a Python SDK for direct library integration, or deploy the AI Gateway (Proxy Server) as a centralized service for your team or organization.
Jump to LiteLLM Proxy (LLM Gateway) Docs
Jump to Supported LLM Providers
Why LiteLLM
Managing LLM calls across providers gets complicated fast — different SDKs, auth patterns, request formats, and error types for every model. LiteLLM removes that friction:
- Unified API — one interface for 100+ LLMs, no provider-specific SDK juggling
- Drop-in OpenAI compatibility — swap providers without rewriting your code
- Production-ready gateway — virtual keys, spend tracking, guardrails, load balancing, and an admin dashboard out of the box
- 8ms P95 latency at 1k RPS (benchmarks)
OSS Adopters
Netflix |
Features
LLMs - Call 100+ LLMs (Python SDK + AI Gateway)
All Supported Endpoints - /chat/completions, /responses, /embeddings, /images, /audio, /batches, /rerank, /a2a, /messages and more.
Python SDK
uv add litellm
An independent litellm-core distribution provides the Python SDK with the same
import litellm API and runtime dependencies. It has no optional extras, CLI entry
points, or bundled dashboard. Install one SDK distribution per environment because
litellm and litellm-core own overlapping Python files. Use litellm for the
proxy, CLI, and optional extras
Build and install core from this checkout while its release integration is pending:
python scripts/build_core_distribution.py --out-dir dist/core
python -m pip install dist/core/litellm_core-*.whl
The builder requires Git, uv and the Rust build toolchain. It reads the release version
from the root pyproject.toml, leaves source files unchanged, and produces a wheel
and a self-contained sdist in dist/core. Run installation in a fresh environment
without litellm
from litellm import completion
import os
os.environ["OPENAI_API_KEY"] = "your-openai-key"
os.environ["ANTHROPIC_API_KEY"] = "your-anthropic-key"
# OpenAI
response = completion(model="openai/gpt-4o", messages=[{"role": "user", "content": "Hello!"}])
# Anthropic
response = completion(model="anthropic/claude-sonnet-4-20250514", messages=[{"role": "user", "content": "Hello!"}])
AI Gateway (Proxy Server)
Getting Started - E2E Tutorial - Setup virtual keys, make your first request
uv tool install 'litellm[proxy]'
litellm --model gpt-4o
import openai
client = openai.OpenAI(api_key="anything", base_url="http://0.0.0.0:4000")
response = client.chat.completions.create(
model="gpt-4o",
messages=[{"role": "user", "content": "Hello!"}]
)
Auto Routing - Choose a model for each prompt (Python SDK + AI Gateway)
Python SDK
Install with uv add litellm and set OPENAI_API_KEY for the models below.
import asyncio
from litellm import Router
router = Router(model_list=[
{"model_name": "fast", "litellm_params": {"model": "openai/gpt-6-luna"}},
{"model_name": "capable", "litellm_params": {"model": "openai/gpt-6.1-sol"}},
{"model_name": "auto", "litellm_params": {
"model": "auto_router/complexity_router",
"complexity_router_config": {
"classifier_type": "heuristic",
"tiers": {"SIMPLE": "fast", "MEDIUM": "fast",
"COMPLEX": "capable", "REASONING": "capable"},
"return_raw_model_name": True,
},
"complexity_router_default_model": "capable",
}},
])
response = asyncio.run(router.acompletion(
model="auto", messages=[{"role": "user", "content": "What is 2+2?"}],
))
print(response.model, response.choices[0].message.content)
AI Gateway (Proxy Server)
Create an Auto Router, then call its model name. Replace auto and the URL below with yours, and set LITELLM_API_KEY to your virtual key.
curl http://localhost:4000/v1/chat/completions \
-H "Authorization: Bearer $LITELLM_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model":"auto","messages":[{"role":"user","content":"What is 2+2?"}]}'
A2A - Invoke A2A Agents (Python SDK + AI Gateway)
Supported Providers - LangGraph, Vertex AI Agent Engine, Azure AI Foundry, Bedrock AgentCore, Pydantic AI
Python SDK - A2A Protocol
from litellm.a2a_protocol import A2AClient
from a2a.types import SendMessageRequest, MessageSendParams
from uuid import uuid4
client = A2AClient(base_url="http://localhost:10001")
request = SendMessageRequest(
id=str(uuid4()),
params=MessageSendParams(
message={
"role": "user",
"parts": [{"kind": "text", "text": "Hello!"}],
"messageId": uuid4().hex,
}
)
)
response = await client.send_message(request)
AI Gateway (Proxy Server)
Step 1. Add your Agent to the AI Gateway — set protocolVersion to 1.0 or 0.3 per agent
Step 2. Call Agent via A2A SDK (requires a2a-sdk>=1.1.0)
import httpx
from a2a.client import A2ACardResolver, ClientConfig, ClientFactory
from a2a.types import Message, Part, Role, SendMessageRequest
from a2a.utils.constants import TransportProtocol
from uuid import uuid4
base_url = "http://localhost:4000/a2a/my-agent" # LiteLLM proxy + agent name
headers = {"Authorization": "Bearer <your-master-key>"} # LiteLLM master key or a virtual key
async with httpx.AsyncClient(headers=headers, timeout=60.0) as http_client:
resolver = A2ACardResolver(httpx_client=http_client, base_url=base_url)
agent_card = await resolver.get_agent_card()
config = ClientConfig(
httpx_client=http_client,
streaming=False,
supported_protocol_bindings=[TransportProtocol.JSONRPC, TransportProtocol.HTTP_JSON],
)
client = ClientFactory(config).create(agent_card)
request = SendMessageRequest(
message=Message(
message_id=uuid4().hex,
role=Role.ROLE_USER,
parts=[Part(text="Hello!")],
)
)
async for event in client.send_message(request):
populated = event.ListFields()
if populated and populated[0][0].name in ("message", "msg"):
print("".join(getattr(p, "text", "") or "" for p in populated[0][1].parts))
MCP Tools - Connect MCP servers to any LLM (Python SDK + AI Gateway)
Python SDK - MCP Bridge
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client
from litellm import mcp_client
import litellm
server_params = StdioServerParameters(command="python", args=["mcp_server.py"])
async with stdio_client(server_params) as (read, write):
async with ClientSession(read, write) as session:
await session.initialize()
# Load MCP tools in OpenAI format
tools = await mcp_client.load_mcp_tools(session=session, format="openai")
# Use with any LiteLLM model
response = await litellm.acompletion(
model="gpt-4o",
messages=[{"role": "user", "content": "What's 3 + 5?"}],
tools=tools
)
AI Gateway - MCP Gateway
Step 1. Add your MCP Server to the AI Gateway
Step 2. Call MCP tools via /chat/completions
curl -X POST 'http://0.0.0.0:4000/v1/chat/completions' \
-H 'Authorization: Bearer <your-master-key>' \
-H 'Content-Type: application/json' \
-d '{
"model": "gpt-4o",
"messages": [{"role": "user", "content": "Summarize the latest open PR"}],
"tools": [{
"type": "mcp",
"server_url": "litellm_proxy/mcp/github",
"server_label": "github_mcp",
"require_approval": "never"
}]
}'
Use with Cursor IDE
{
"mcpServers": {
"LiteLLM": {
"url": "http://localhost:4000/mcp/",
"headers": {
"x-litellm-api-key": "Bearer <your-master-key>"
}
}
}
}
For MCP OAuth, an upstream may advertise dynamic client registration but refuse requests with HTTP 401 or 403. If the provider requires a pre-registered OAuth app, configure its credentials.client_id and, when required, credentials.client_secret on the MCP server. This skips dynamic registration in the gateway sign-in flow. The provider must approve the app for MCP access; reaching its authorization page does not establish that login or tool calls will succeed
Agents - Run Claude Code, Codex, OpenCode, pi or Deep Agents on any model (Python SDK)
Python SDK - Agents
import litellm
from litellm import Harness, sandbox
result = litellm.agent(
Harness.CLAUDE_CODE, # or Harness.CODEX, Harness.OPENCODE, Harness.PI, Harness.DEEPAGENTS
"Find why tests/test_router.py is flaky and fix it.",
sandbox=sandbox.local("./repo"),
model="litellm_proxy/claude-sonnet-4-5", # a model group on your AI Gateway
)
print(result.text, result.cost, [f.path for f in result.files])
Set LITELLM_PROXY_API_BASE and LITELLM_PROXY_API_KEY and every model call the agent makes goes through your AI Gateway, tagged harness,claude_code. Drop the litellm_proxy/ prefix to call a provider directly. Install starlette uvicorn plus the agent's CLI (claude, codex, opencode or pi), or deepagents langchain-litellm for Deep Agents.
Supported Providers (Website Supported Models | Docs)
Get Started
You can use LiteLLM through either the Proxy Server or Python SDK. Both give you a unified interface to access multiple LLMs (100+ LLMs). Choose the option that best fits your needs:
| LiteLLM AI Gateway | LiteLLM Python SDK | |
|---|---|---|
| Use Case | Central service (LLM Gateway) to access multiple LLMs | Use LiteLLM directly in your Python code |
| Who Uses It? | Gen AI Enablement / ML Platform Teams | Developers building LLM projects |
| Key Features | Centralized API gateway with authentication and authorization, multi-tenant cost tracking and spend management per project/user, per-project customization (logging, guardrails, caching), virtual keys for secure access control, admin dashboard UI for monitoring and management | Direct Python library integration in your codebase, Router with retry/fallback logic across multiple deployments (e.g. Azure/OpenAI) - Router, application-level load balancing and cost tracking, exception handling with OpenAI-compatible errors, observability callbacks (Lunary, MLflow, Langfuse, etc.) |
Stable Release: Use docker images with the -stable tag. These have undergone 12 hour load tests, before being published. More information about the release cycle here
Support for more providers. Missing a provider or LLM Platform, raise a feature request.
Deploy on AWS or GCP with Terraform
Run the LiteLLM proxy as a production-ready componentized stack (gateway, backend, UI on separate services; managed Postgres + Redis + object store) using the published Terraform modules. Both modules are on the public Terraform Registry — no auth needed.
AWS — ECS Fargate + Aurora + ElastiCache + ALB
— opens an in-browser shell, already authenticated to your AWS account. Once inside, run:
git clone https://github.com/BerriAI/litellm.git
cd litellm/terraform/litellm/aws/examples/default
cp terraform.tfvars.example terraform.tfvars # edit region/tenant/env
terraform init && terraform apply
Or call the module from your own root config:
# main.tf
terraform {
required_version = ">= 1.6.0"
required_providers {
aws = { source = "hashicorp/aws", version = "~> 5.60" }
}
}
provider "aws" {
region = "us-west-2"
}
module "litellm" {
source = "BerriAI/litellm/aws"
version = "~> 1.89"
region = "us-west-2"
azs = ["us-west-2a", "us-west-2b"]
tenant = "acme"
env = "prod"
# Production: provide an ACM cert. Without one, set allow_plaintext_alb = true
# (dev/trial only).
# acm_certificate_arn = "arn:aws:acm:us-west-2:111122223333:certificate/..."
allow_plaintext_alb = true
}
output "litellm_url" {
value = module.litellm.alb_dns_name
}
terraform init
terraform apply
Provider API keys live in AWS Secrets Manager; reference ARNs via gateway_extra_secrets. Full input list and architecture diagram on the registry page.
GCP — Cloud Run + Cloud SQL + Memorystore + HTTPS LB
Real 1-click. Opens Cloud Shell, clones the terraform-google-litellm module mirror at the latest stable release (a small download instead of the full litellm repo), and walks you through terraform apply via a built-in DeployStack tutorial. Pick the project, the tutorial sets up the Artifact Registry remote repo, writes terraform.tfvars from your answers, and runs apply
To call the module from your own config instead, Cloud Run can't pull from ghcr.io directly, so first set up a one-time Artifact Registry remote repo backed by GHCR:
gcloud artifacts repositories create litellm \
--location=us-central1 \
--repository-format=docker \
--mode=remote-repository \
--remote-docker-repo=https://ghcr.io \
--project=my-gcp-project
Then:
# main.tf
terraform {
required_version = ">= 1.6.0"
required_providers {
google = { source = "hashicorp/google", version = "~> 6.10" }
google-beta = { source = "hashicorp/google-beta", version = "~> 6.10" }
}
}
provider "google" { project = "my-gcp-project"; region = "us-central1" }
provider "google-beta" { project = "my-gcp-project"; region = "us-central1" }
module "litellm" {
source = "BerriAI/litellm/google"
version = "~> 1.89"
project_id = "my-gcp-project"
region = "us-central1"
tenant = "acme"
env = "prod"
# Replace my-gcp-project with your GCP project ID (same value as project_id above).
image_registry = "us-central1-docker.pkg.dev/my-gcp-project/litellm/berriai"
# Production: provide DNS already pointing at the LB IP for Google-managed certs.
# Without one, set allow_plaintext_lb = true (dev/trial only).
# lb_domains = ["proxy.example.com"]
allow_plaintext_lb = true
}
output "litellm_url" {
value = module.litellm.load_balancer_url
}
terraform init
terraform apply
Provider API keys live in Secret Manager; reference resource IDs (e.g. projects/my-gcp-project/secrets/openai-api-key) via gateway_extra_secrets. Full input list and architecture diagram on the registry page.
Both stacks include
- The full componentized split (gateway / backend / UI as independent services)
- Managed Postgres (writer + reader) and Redis
- Versioned object store for proxy state + file uploads
- An auto-generated
LITELLM_MASTER_KEYin your cloud's secret manager - A one-off migration job that runs
prisma migrate deploybefore the proxy starts - The same
proxy_configsurface as the Helm chart — pass YAML as a typed map
The Terraform modules live at terraform/litellm/aws/ and terraform/litellm/gcp/ in this repo; the registry entries are read-only mirrors updated on each release.
Run in Developer Mode
Services
- Setup .env file in root
- Run dependent services
docker-compose up db prometheus
Backend
- Run
make bootstrap - Start proxy backend:
uv run python litellm/proxy/proxy_cli.py
Frontend
- Navigate to
ui/litellm-dashboard(dependencies were already installed w/make bootstrap) - Start dashboard:
npm run dev
Verify Docker Image Signatures
All LiteLLM Docker images published to GHCR are signed with cosign. Releases are signed with the key introduced in commit e82a3c6.
Verify using the pinned commit hash (recommended):
A commit hash is cryptographically immutable, so this is the strongest way to ensure you are using the published signing key:
cosign verify \
--key https://raw.githubusercontent.com/BerriAI/litellm/e82a3c646908ba0a6ee0beddc4310d7a6cac4065/cosign.pub \
ghcr.io/berriai/litellm:<release-tag>
Verify using a release tag (convenience):
Tags are protected in this repository and resolve to the same key. This option is easier to read but relies on tag protection rules:
cosign verify \
--key https://raw.githubusercontent.com/BerriAI/litellm/<release-tag>/cosign.pub \
ghcr.io/berriai/litellm:<release-tag>
Replace <release-tag> with the version you are deploying (e.g. v1.83.0-stable).
Enterprise
For companies that need better security, user management and professional support
Get an Enterprise License Talk to founders
This covers:
- ✅ Features under the LiteLLM Commercial License:
- ✅ Feature Prioritization
- ✅ Custom Integrations
- ✅ Professional Support - Dedicated discord + slack
- ✅ Custom SLAs
- ✅ Secure access with Single Sign-On
Contributing
We welcome contributions to LiteLLM! Whether you're fixing bugs, adding features, or improving documentation, we appreciate your help.
If you want to work closely with our team, check out LiteLLM OSS Champions, our program for trusted OSS contributors with their own Slack channel and a voice in the roadmap
Quick Start for Contributors
This requires uv to be installed.
git clone https://github.com/BerriAI/litellm.git
cd litellm
make install-dev # Install development dependencies
make format # Format your code
make lint # Run all linting checks
make test-unit # Run unit tests
make format-check # Check formatting only
For detailed contributing guidelines, see CONTRIBUTING.md.
📖 Contributing to documentation? The LiteLLM docs have moved to a separate repository: BerriAI/litellm-docs. Please open doc PRs there. Docs are served at docs.litellm.ai.
Code Quality / Linting
LiteLLM follows the Google Python Style Guide.
Our automated checks include:
- Ruff for formatting, linting, and code quality
- basedpyright for type checking
- Circular import detection
- Import safety checks
All these checks must pass before your PR can be merged.
Support / talk with founders
- Schedule Demo 👋
- Community Discord 💭
- Community Slack 💭
- Our emails ✉️ ishaan@berri.ai / krrish@berri.ai
