Go to file
Sameer Kankute 1294165768
feat(mcp): support MCP access group names in URL-based namespacing (#27726)
* feat(mcp): support MCP access group names in URL-based namespacing

Extends dynamic_mcp_route to resolve /{name}/mcp requests where {name}
is an MCP access group tag or a comma-separated list of servers/groups,
matching what the documentation promised but the handler did not implement.

Resolution order: registered server alias → toolset → comma-separated
list → single access group tag (404 if none match).

Adds unit tests covering all four resolution paths plus 404 cases.

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(mcp): address Greptile review comments on dynamic_mcp_route

- Move comma-separated check before toolset DB lookup so comma names
  short-circuit without hitting the database
- Cache access-group DB lookups via user_api_key_cache to avoid a raw
  find_many on every request (matches toolset caching pattern)
- Remove unused response_started variable from _forward_as_mcp_path
- Update tests to assert comma list skips toolset call and to mock cache

Co-authored-by: Cursor <cursoragent@cursor.com>

* refactor(mcp): extract helpers to fix PLR0915 too-many-statements in dynamic_mcp_route

Extract _mcp_forward_as_path and _is_mcp_access_group_cached as
module-level helpers so dynamic_mcp_route stays under the 50-statement
limit. Update tests to patch the new module-level symbols directly.

Co-authored-by: Cursor <cursoragent@cursor.com>

* Avoid caching missing MCP access groups

* fix(mcp): stream MCP responses via _stream_mcp_asgi_response instead of buffering

_mcp_forward_as_path previously accumulated the full response body in
memory before sending it. Replace the buffering custom_send pattern with
_stream_mcp_asgi_response, which uses an asyncio.Queue bridge so chunks
are yielded to the client as they arrive, preventing unbounded memory
growth on large or long-lived MCP responses.

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(mcp): short-TTL negative cache for access-group existence lookup

An unauthenticated caller could repeatedly request /<unknown>/mcp and
force a fresh DB lookup for the access-group existence check on every
request (only positive results were cached). Cache negative results
for a short DEFAULT_MCP_ACCESS_GROUP_NEGATIVE_CACHE_TTL window (10s by
default) so the DB is shielded from flooding while a transient DB error
(which surfaces as an empty list) cannot hide a real group for long.

https://claude.ai/code/session_01SjyPmwfmrq8fveFgw9iHW9

* fix(mcp): use plain int for access-group negative cache TTL

Drop the os.getenv wrapper around DEFAULT_MCP_ACCESS_GROUP_NEGATIVE_CACHE_TTL
to avoid the documentation_test_env_keys check failing on the new variable.
The negative-cache window is a small internal tuning constant, not a
user-facing knob, so a plain integer is clearer than an env override.

https://claude.ai/code/session_01SjyPmwfmrq8fveFgw9iHW9

* fix(mcp): validate, dedupe, and cap CSV tokens in dynamic MCP route

For /{name1,name2,...}/mcp, validate every token resolves to a known
server alias or access group, dedupe case-insensitively, and cap at
DEFAULT_MCP_NAMESPACE_CSV_MAX_TOKENS=16 before forwarding.

- Bounds the per-request DB / cache fan-out an authenticated caller can
  trigger by stuffing the path with tokens (raised by veria-ai).
- Returns 404 instead of forwarding when no token resolves, so the
  downstream server filter cannot silently fall back to the full
  allowed_mcp_servers list (raised by Cursor agentic security review).
- Forwards only the resolved subset, so unknown tokens cannot ride along
  into the downstream filter.

Co-authored-by: Mateo Wang <mateo-berri@users.noreply.github.com>

* fix(mcp): exact-match CSV token dedupe to preserve case-sensitive distinct tokens

Bugbot flagged that case-insensitive dedup on `MyGroup,mygroup` could
collapse to whichever case appeared first and silently drop the matching
casing if the downstream resolver is case-sensitive. Switch to exact-match
dedup so distinct casings survive; whitespace-only differences still
collapse via the .strip() before comparison.

Co-authored-by: Mateo Wang <mateo-berri@users.noreply.github.com>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Claude <claude@anthropic.com>
Co-authored-by: mateo-berri <mateo@berri.ai>
Co-authored-by: Mateo Wang <mateo-berri@users.noreply.github.com>
2026-05-13 20:20:38 -07:00
.circleci ci(circleci): enable Rerun Failed Tests for all pytest jobs (#27155) 2026-05-05 17:27:09 -07:00
.devcontainer build: migrate packaging, CI, and Docker from Poetry to uv (#25007) 2026-04-09 11:46:23 -07:00
.github Litellm key rotation bug (#27756) 2026-05-12 17:16:37 -07:00
.semgrep/rules security: remove .claude/settings.json and add semgrep rule to prevent re-adding 2026-03-25 11:57:43 -07:00
ci_cd Drop dep bumps + black-26 reformat to clear fork CI policy 2026-05-07 23:04:52 +00:00
cookbook Drop dep bumps + black-26 reformat to clear fork CI policy 2026-05-07 23:04:52 +00:00
db_scripts Drop dep bumps + black-26 reformat to clear fork CI policy 2026-05-07 23:04:52 +00:00
deploy Fix: tag budget reset must drop stale management-cache entry (#27568) 2026-05-10 00:18:55 +00:00
dist
docker Fix: tag budget reset must drop stale management-cache entry (#27568) 2026-05-10 00:18:55 +00:00
docs fix(hosted_vllm): normalize custom tools for chat completions (#25763) 2026-05-05 17:27:02 -07:00
enterprise Drop dep bumps + black-26 reformat to clear fork CI policy 2026-05-07 23:04:52 +00:00
litellm feat(mcp): support MCP access group names in URL-based namespacing (#27726) 2026-05-13 20:20:38 -07:00
litellm-proxy-extras feat(mcp): add delegate_auth_to_upstream flag for PKCE passthrough (#27834) 2026-05-13 12:06:13 -07:00
scripts ci: add manually-triggered mutation testing workflow (#27576) 2026-05-11 15:19:57 -07:00
tests feat(mcp): support MCP access group names in URL-based namespacing (#27726) 2026-05-13 20:20:38 -07:00
ui/litellm-dashboard feat(mcp): add delegate_auth_to_upstream flag for PKCE passthrough (#27834) 2026-05-13 12:06:13 -07:00
.dockerignore fix critical CVE vulnerabliltes (#20683) 2026-02-07 22:23:01 -08:00
.env.example
.flake8
.git-blame-ignore-revs
.gitattributes
.gitguardian.yaml build: migrate packaging, CI, and Docker from Poetry to uv (#25007) 2026-04-09 11:46:23 -07:00
.gitignore Refactor Bedrock response stream shape handling (#27257) 2026-05-06 17:39:38 -07:00
.npmrc [Fix] CI/Tooling: Correct min-release-age value in .npmrc files 2026-04-29 19:49:27 -07:00
AGENTS.md Fix: tag budget reset must drop stale management-cache entry (#27568) 2026-05-10 00:18:55 +00:00
ARCHITECTURE.md
CLAUDE.md Fix: tag budget reset must drop stale management-cache entry (#27568) 2026-05-10 00:18:55 +00:00
codecov.yaml [Chore] CI: Block PRs that drop overall code coverage (#27340) 2026-05-06 16:41:50 -07:00
CONTRIBUTING.md build: migrate packaging, CI, and Docker from Poetry to uv (#25007) 2026-04-09 11:46:23 -07:00
cosign.pub [Infra] Add release workflow and cosign public key 2026-03-31 14:30:27 -07:00
docker-compose.hardened.yml
docker-compose.yml feat: add read-replica routing for Prisma DB via DATABASE_URL_READ_REPLICA (#27493) 2026-05-08 21:05:50 -07:00
Dockerfile fix(docker): restore npm@11.14.0 lost in merge resolution 2026-05-07 17:25:10 -07:00
GEMINI.md build: migrate packaging, CI, and Docker from Poetry to uv (#25007) 2026-04-09 11:46:23 -07:00
LICENSE
license_cache.json build: migrate packaging, CI, and Docker from Poetry to uv (#25007) 2026-04-09 11:46:23 -07:00
Makefile [Infra] Promote internal staging to main (#27245) 2026-05-05 16:15:03 -07:00
mcp_servers.json
model_prices_and_context_window.json fix(pricing): GPT-4o-Transcribe Pricing (#27875) 2026-05-13 17:42:05 -07:00
package-lock.json [Infra] Promote internal staging to main (#27245) 2026-05-05 16:15:03 -07:00
package.json [Infra] Promote internal staging to main (#27245) 2026-05-05 16:15:03 -07:00
policy_templates.json feat: Add Canadian PII protection (PIPEDA) (#22951) 2026-03-06 18:27:31 -08:00
prometheus.yml
provider_endpoints_support.json feat(audio_transcription): add NVIDIA Riva STT provider (#27185) 2026-05-05 17:17:51 -07:00
proxy_server_config.yaml fix(tests): swap dall-e to gpt-image-1 after openai deprecation 2026-05-12 16:55:18 -07:00
pyproject.toml ci: add manually-triggered mutation testing workflow (#27576) 2026-05-11 15:19:57 -07:00
pyrightconfig.json
README.md [Infra] Promote internal staging to main (#27245) 2026-05-05 16:15:03 -07:00
render.yaml
ruff.toml [Fix] CI: fix 6 more CircleCI job failures from uv migration 2026-04-10 21:06:25 -07:00
schema.prisma feat(mcp): add delegate_auth_to_upstream flag for PKCE passthrough (#27834) 2026-05-13 12:06:13 -07:00
security.md chore: update security.md (#24871) 2026-03-31 13:13:18 -07:00
taplo.toml
uv.lock Fix: tag budget reset must drop stale management-cache entry (#27568) 2026-05-10 00:18:55 +00:00

🚅 LiteLLM

LiteLLM AI Gateway

Open Source AI Gateway for 100+ LLMs. Self-hosted. Enterprise-ready. Call any LLM in OpenAI format.

Deploy to Render Deploy on Railway

LiteLLM Proxy Server (AI Gateway) | Hosted Proxy | Enterprise Tier | Website

PyPI Version GitHub Stars Y Combinator W23 Whatsapp Discord Slack CodSpeed

Group 7154 (1)

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

Stripe image Google ADK Greptile OpenHands

Netflix

OpenAI Agents SDK

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
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!"}]
)

Docs: LLM Providers

Agents - 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

Step 2. Call Agent via A2A SDK

from a2a.client import A2ACardResolver, A2AClient
from a2a.types import MessageSendParams, SendMessageRequest
from uuid import uuid4
import httpx

base_url = "http://localhost:4000/a2a/my-agent"  # LiteLLM proxy + agent name
headers = {"Authorization": "Bearer sk-1234"}    # LiteLLM Virtual Key

async with httpx.AsyncClient(headers=headers) as httpx_client:
    resolver = A2ACardResolver(httpx_client=httpx_client, base_url=base_url)
    agent_card = await resolver.get_agent_card()
    client = A2AClient(httpx_client=httpx_client, agent_card=agent_card)

    request = SendMessageRequest(
        id=str(uuid4()),
        params=MessageSendParams(
            message={
                "role": "user",
                "parts": [{"kind": "text", "text": "Hello!"}],
                "messageId": uuid4().hex,
            }
        )
    )
    response = await client.send_message(request)

Docs: A2A Agent Gateway

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 experimental_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 experimental_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 sk-1234' \
  -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 sk-1234"
      }
    }
  }
}

Docs: MCP Gateway

Supported Providers (Website Supported Models | Docs)

Provider /chat/completions /messages /responses /embeddings /image/generations /audio/transcriptions /audio/speech /moderations /batches /rerank
Abliteration (abliteration)
AI/ML API (aiml)
AI21 (ai21)
AI21 Chat (ai21_chat)
Aleph Alpha
Amazon Nova
Anthropic (anthropic)
Anthropic Text (anthropic_text)
Anyscale
AssemblyAI (assemblyai)
Auto Router (auto_router)
AWS - Bedrock (bedrock)
AWS - Sagemaker (sagemaker)
Azure (azure)
Azure AI (azure_ai)
Azure Text (azure_text)
Baseten (baseten)
Bytez (bytez)
Cerebras (cerebras)
Clarifai (clarifai)
Cloudflare AI Workers (cloudflare)
Codestral (codestral)
Cohere (cohere)
Cohere Chat (cohere_chat)
CometAPI (cometapi)
CompactifAI (compactifai)
Custom (custom)
Custom OpenAI (custom_openai)
Dashscope (dashscope)
Databricks (databricks)
DataRobot (datarobot)
Deepgram (deepgram)
DeepInfra (deepinfra)
Deepseek (deepseek)
ElevenLabs (elevenlabs)
Empower (empower)
Fal AI (fal_ai)
Featherless AI (featherless_ai)
Fireworks AI (fireworks_ai)
FriendliAI (friendliai)
Galadriel (galadriel)
GitHub Copilot (github_copilot)
GitHub Models (github)
Google - PaLM
Google - Vertex AI (vertex_ai)
Google AI Studio - Gemini (gemini)
GradientAI (gradient_ai)
Groq AI (groq)
Heroku (heroku)
Hosted VLLM (hosted_vllm)
Huggingface (huggingface)
Hyperbolic (hyperbolic)
IBM - Watsonx.ai (watsonx)
Infinity (infinity)
Jina AI (jina_ai)
Lambda AI (lambda_ai)
Lemonade (lemonade)
LiteLLM Proxy (litellm_proxy)
Llamafile (llamafile)
LM Studio (lm_studio)
Maritalk (maritalk)
Meta - Llama API (meta_llama)
Mistral AI API (mistral)
Moonshot (moonshot)
Morph (morph)
Nebius AI Studio (nebius)
NLP Cloud (nlp_cloud)
Novita AI (novita)
Nscale (nscale)
Nvidia NIM (nvidia_nim)
OCI (oci)
Ollama (ollama)
Ollama Chat (ollama_chat)
Oobabooga (oobabooga)
OpenAI (openai)
OpenAI-like (openai_like)
OpenRouter (openrouter)
OVHCloud AI Endpoints (ovhcloud)
Perplexity AI (perplexity)
Petals (petals)
Predibase (predibase)
Recraft (recraft)
Replicate (replicate)
Sagemaker Chat (sagemaker_chat)
Sambanova (sambanova)
Snowflake (snowflake)
Text Completion Codestral (text-completion-codestral)
Text Completion OpenAI (text-completion-openai)
Together AI (together_ai)
Topaz (topaz)
Triton (triton)
V0 (v0)
Vercel AI Gateway (vercel_ai_gateway)
VLLM (vllm)
Volcengine (volcengine)
Voyage AI (voyage)
WandB Inference (wandb)
Watsonx Text (watsonx_text)
xAI (xai)
Xinference (xinference)

Read the 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.

Run in Developer Mode

Services

  1. Setup .env file in root
  2. Run dependant services docker-compose up db prometheus

Backend

  1. (In root) create virtual environment python -m venv .venv
  2. Activate virtual environment source .venv/bin/activate
  3. Install dependencies uv sync --all-extras --group proxy-dev
  4. uv run prisma generate
  5. prisma generate
  6. Start proxy backend python litellm/proxy/proxy_cli.py

Frontend

  1. Navigate to ui/litellm-dashboard
  2. Install dependencies npm install
  3. Run npm run dev to start the dashboard

Verify Docker Image Signatures

All LiteLLM Docker images published to GHCR are signed with cosign. Every release is signed with the same key introduced in commit 0112e53.

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 original signing key:

cosign verify \
  --key https://raw.githubusercontent.com/BerriAI/litellm/0112e53046018d726492c814b3644b7d376029d0/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.

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:

  • Black for code formatting
  • Ruff for linting and code quality
  • MyPy for type checking
  • Circular import detection
  • Import safety checks

All these checks must pass before your PR can be merged.

Support / talk with founders

Contributors