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Deepanshu Lulla 363d56f917
feat(proxy): add per-deployment keepalive_seconds SSE heartbeat to prevent load-balancer timeout on long streams (#34423)
* feat(proxy): add per-deployment keepalive_seconds SSE heartbeat for long-running streams

Adds _iter_with_keepalive, _keepalive_from_deployment_config, and
_resolve_keepalive_seconds helpers to proxy_server.py. When enabled
(keepalive_seconds > 0 in request body or deployment litellm_params),
async_data_generator emits ': ping\n\n' SSE comment frames every N
seconds during idle upstream intervals, preventing load-balancer
idle-timeout drops on long chain-of-thought reasoning streams.

The hot path (keepalive_seconds absent or 0) is a plain async-for with
no per-chunk Task wrapping — zero overhead. Includes 8 new unit tests
covering sentinel emission, hot-path pass-through, early-close cleanup,
priority resolution, deployment-config lookup, and end-to-end heartbeat
emission through async_data_generator.

Registers keepalive_seconds in all_litellm_params (types/utils.py) so
the parameter is not stripped from request bodies. Adds the field to
LiteLLMParamsTypedDict and GenericLiteLLMParams (types/router.py) so
deployment YAML config is parsed and validated.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(proxy): narrow BaseException to CancelledError to fix BLE001 strict lint gate

* fix: use explicit None check instead of truthiness in keepalive_seconds extraction

`float(raw or 0)` would treat any falsy value (including the integer 0)
as absent and substitute 0.0 before float() saw it. Replace with
`float(raw) if raw is not None else 0.0` so a caller-supplied zero is
correctly passed through to the `value <= 0` guard that disables
keepalive, rather than being silently overwritten.

* fix(proxy): don't guess a deployment's keepalive_seconds when model_id is missing

When a streaming response lacks _hidden_params.model_id, the fallback that
looks up keepalive_seconds by model_name previously returned the first
configured deployment's value, which could apply the wrong interval (or
override an explicit disable) when multiple deployments share the same
model_name with different keepalive_seconds settings. Only resolve the
fallback when every deployment agrees; otherwise leave it unset.

* fix(proxy): also treat an unset keepalive_seconds as disagreement in the fallback

The model_name fallback for keepalive_seconds only compared configured
values, filtering out deployments that leave the field unset entirely.
That meant a deployment with no keepalive_seconds configured could still
inherit a sibling deployment's interval when model_id is unavailable.
Compare the raw per-deployment value (including None for unset) so an
unconfigured deployment never silently adopts another's heartbeat.

* fix(proxy): deployment-level keepalive_seconds: 0 is a hard disable clients can't override

Previously an authenticated client's request-level keepalive_seconds always
took precedence over the deployment default, including when a deployment
operator explicitly set keepalive_seconds: 0 to disable heartbeats. That let
any client re-enable heartbeats for a deployment the operator opted out of,
using them to keep an idle-looking stream alive past a load balancer's idle
timeout and hold a parallel-request slot open longer than intended.

Treat an explicit deployment-level 0 as authoritative: resolve the
deployment's configured value first, and short-circuit to disabled before
ever looking at the request body if the deployment hard-disabled it.

* fix(proxy): a stale (unresolvable) model_id must not fall through to model_name guessing

A populated _hidden_params.model_id names the specific deployment that
served a stream. If that ID no longer resolves (e.g. a deployment removed
by a config reload mid-stream), the resolver was falling through to the
model_name-based fallback, letting a currently-live sibling deployment's
keepalive_seconds silently apply to a stream it never served. Return None
once a populated model_id fails to resolve, rather than degrading to a
guess.

* fix(proxy): keepalive_seconds is operator-only by default; require deployment opt-in for client override

A security review flagged that a client's request-level keepalive_seconds
could unilaterally enable heartbeats for any deployment, even one that
never configured keepalive_seconds at all, letting an authenticated client
defeat load-balancer idle timeouts and hold a parallel-request slot open
for longer than the deployment operator ever intended, with no way for
the operator to prevent it short of explicitly setting keepalive_seconds: 0.

Add allow_client_keepalive_override (default False) to LiteLLMParamsTypedDict
and GenericLiteLLMParams. _resolve_keepalive_seconds now ignores the request
body's keepalive_seconds entirely unless the resolved deployment explicitly
grants override permission; only the deployment's own configured value (or
disabled, if unset) applies otherwise. An explicit deployment-level 0 still
takes priority over everything, including a grant of override permission.

* fix(proxy): register allow_client_keepalive_override in all_litellm_params

Caught during live proxy verification against the real Anthropic API:
allow_client_keepalive_override was added to LiteLLMParamsTypedDict and
GenericLiteLLMParams but never registered in all_litellm_params, so it
leaked straight through into the provider request body as an unrecognized
field. Anthropic rejected every call on a deployment that had this field
configured with a 400 ("Extra inputs are not permitted"), regardless of
its value. Register it alongside keepalive_seconds so it's stripped
before reaching the provider, matching what keepalive_seconds already
does.

* feat(proxy): support keepalive_seconds via x-litellm-keepalive-seconds header

Some clients (e.g. the Vercel AI SDK) can set custom headers more easily
than extra JSON body fields. Add x-litellm-keepalive-seconds, following
the existing x-litellm-timeout/x-litellm-stream-timeout/x-litellm-num-retries
convention in LiteLLMProxyRequestSetup: the header merges into the same
data["keepalive_seconds"] field the request body already populates, so it
goes through the exact same _resolve_keepalive_seconds precedence and the
allow_client_keepalive_override gate -- a header can't enable heartbeats
for a deployment that hasn't opted in any more than the body field can.

Verified live against the real Anthropic API: the header produces real
heartbeats on an opt-in deployment (88 pings over a genuine long-reasoning
stall) and is silently ignored on a deployment without override permission
(0 pings), matching the existing body-field behavior exactly.

* chore: rebase onto litellm_internal_staging, drop unrelated credential_migration.py reformat, fix budget-ratchet drift

Rebased onto the current litellm_internal_staging (merge-base was 5 days
stale). Dropped the now-redundant schema.d.ts-only regen commit entirely
(the new base's own schema.d.ts already supersedes it) and regenerated
schema.d.ts fresh against the new base.

Reverted litellm/proxy/management_endpoints/credential_migration.py to
exactly match litellm_internal_staging: it was a pure reformat with no
semantic change, unrelated to this PR, flagged by review as unnecessary
noise in an encryption-migration file.

Fixed two lint-budget-ratchet failures caused by the base's ceilings
tightening since this branch last synced (other merged work lowered
ANN401/LIT001 budgets; this code was previously under budget and didn't
change):
- _iter_with_keepalive's aiter param: Any -> AsyncIterator[Any], a real
  narrowing (it's always the result of .__aiter__()).
- _keepalive_from_deployment_config/_resolve_keepalive_seconds's
  request_data param: dict[str, Any] -> Mapping[str, Any], matching the
  existing read-only-dict convention already used elsewhere in this file
  (_apply_ssrf_general_settings, _build_redis_usage_cache, etc.) for
  params that are only ever read, never mutated.
- response/raw params: dropped the explicit `Any` annotation to match
  async_data_generator's own (deliberately unannotated) `response` param,
  its actual caller.
- litellm_pre_call_utils.py's new headers param: dict -> Mapping[str, str],
  same read-only-dict rationale.

* fix(proxy): freeze the transient collections in the keepalive helpers

_iter_with_keepalive and _keepalive_from_deployment_config built a set
literal for asyncio.wait, a set comprehension for the per-deployment
config-agreement check, and two dict-literal fallbacks, all flagged by
the LIT002 mutable-collection-construction gate. Switched to a tuple
for asyncio.wait, a frozenset-wrapped generator plus next(iter(...))
for the config check, and a shared MappingProxyType({}) empty mapping
for the fallbacks.

* fix(proxy): trust metadata.model_info.id over the stale model group after a router fallback

Greptile P1: when a streaming request falls back from model group A to
group B and the response's _hidden_params carries no model_id,
_keepalive_from_deployment_config fell straight through to guessing
via request_data["model"], which still names the pre-fallback group A
since the fallback handler mutates its own local **kwargs copy, not
this dict. request_data[metadata|litellm_metadata]["model_info"]["id"],
by contrast, is mutated on this same dict by
Router._update_kwargs_with_deployment on every attempt including
fallbacks (the same source ProxyLogging._build_litellm_call_info uses
for logging), so check it before falling through to the model-name
guess.

Added two regression tests that fail on the prior code (assert
get_model_list is never called once metadata.model_info.id resolves)
and pass with the fix.

* Revert "fix(proxy): trust metadata.model_info.id over the stale model group after a router fallback"

This reverts commit d779067864.

* fix(proxy): satisfy the new LIT010/ANN001 gates in the keepalive helpers

litellm_internal_staging picked up a LIT010 (every local/module variable
must be declared Final unless it's genuinely rebound) and tightened
ANN001 (missing parameter annotations) since this branch last synced.
Annotated every single-assignment local and module constant with
Final, suppressed pending's loop-carried reassignment with
# rebind-ok, and typed the previously-bare response/raw parameters as
object with isinstance narrowing at their use sites instead of cast
(LIT006 discourages cast; validate into a concrete type instead).

Also swapped the hand-rolled getattr(response, "_hidden_params", None)
+ isinstance(hidden, dict) check for the existing
get_hidden_params_dict() helper already used for this exact purpose
elsewhere in this file and in common_request_processing.py.

* fix(proxy): re-resolve keepalive_seconds per chunk to track mid-stream fallback

Greptile P1: the router can perform a mid-stream fallback to a
different deployment partway through a stream (MidStreamFallbackError
in router.py), and Router._apply_fallback_hidden_params_to_item merges
the fallback deployment's hidden params onto every subsequent chunk.
But _resolve_keepalive_seconds was only ever called once, before
iteration started, against the pre-fallback response wrapper, so a
stream that fell back to a deployment with a different (or disabled)
keepalive policy kept using the original deployment's interval for the
rest of the stream.

_iter_with_keepalive now takes a resolve_keepalive_seconds(item)
callback and re-resolves after every real chunk using that chunk's own
_hidden_params (which do carry the fallback deployment's identity),
rather than trusting the value picked before iteration began. Updated
the three existing timing tests to inject a constant-returning
resolver, since they pin the sentinel/cancellation mechanics rather
than re-resolution, and added two regression tests (interval lowered
and raised mid-stream) that fail against the prior static-resolve
signature and pass with the fix.

* fix(proxy): keep re-resolving keepalive even when a stream starts disabled

Greptile P1: a stream that starts on a deployment with keepalive off
(or unset) skipped _iter_with_keepalive entirely at the call site, so
a mid-stream fallback to a deployment that enables it never got a
chance to activate heartbeats for the rest of that stream, risking the
exact load-balancer idle-timeout this feature exists to prevent.

_iter_with_keepalive now has an internal fast path for
keepalive_seconds <= 0 that still re-resolves after every chunk (no
asyncio.create_task/wait overhead while inactive, same cost as a bare
async for), so activation from a disabled start works the same way
deactivation and interval changes already do. The caller now only
skips wrapping entirely when there's no router to ever fall back
through in the first place (llm_router is None), rather than whenever
the first chunk's deployment happens to start with keepalive off.

Added a regression test that starts keepalive_seconds=0, has the
resolver enable a short interval on a later chunk, and asserts
sentinels appear afterward; it fails against the prior
call-site-gated code and passes with the fix.

* perf(proxy): memoize keepalive resolution per chunk's model_id

_resolve_keepalive_seconds ran a full llm_router.get_deployment() Pydantic
rebuild after every streamed chunk, even when keepalive was unconfigured
anywhere in the deployment list, since async_data_generator wraps every
stream once a router exists. Caching the result by model_id keeps mid-stream
fallback re-resolution correct while paying the router lookup once per
deployment instead of once per token.

* fix(proxy): expire cached keepalive resolution after a bounded TTL

veria-ai flagged that caching by model_id alone lets an already-in-flight
stream keep evading a live config reload (deployment removed, keepalive
disabled, or client override revoked) for the rest of the stream. Expiring
the memo after _KEEPALIVE_CACHE_TTL_SECONDS bounds that window instead of
freezing the resolved value for the stream's full lifetime, while still
avoiding a full deployment rebuild on every chunk in the steady state.

Also fixes add_litellm_data_for_backend_llm_call's now-required request_data
kwarg in the header-merge test, picked up by rebasing onto
litellm_internal_staging.

---------

Co-authored-by: Deepanshu <deepanshu.lulla@alpha-sense.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-08-10 16:47:17 -07:00
.cargo ci: harden cargo fetches during maturin builds (#31348) 2026-06-25 14:31:05 -07:00
.circleci ci: pin Node on the Playwright UI lanes so npm ci meets the engines floor 2026-08-04 16:31:38 -07:00
.devcontainer build: migrate packaging, CI, and Docker from Poetry to uv (#25007) 2026-04-09 11:46:23 -07:00
.githooks chore(hooks): enforce Conventional Commits and Conventional Branches (#30174) 2026-06-11 10:00:23 -07:00
.github refactor(ui): make illegal DataTable prop combinations unrepresentable 2026-08-10 15:19:39 -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
backend fix(docker): bake the componentized prisma engines at /opt/prisma so any uid can start (#35989) 2026-08-05 13:38:46 -07:00
ci_cd ci: enforce format assertions so calendar-impossible deprecation dates fail validation 2026-07-28 16:11:22 -07:00
cookbook feat(cookbook): add a Grafana dashboard for the OTel GenAI metrics (#35159) 2026-07-30 17:29:40 +00:00
db_scripts fix(db_scripts): pin the tool spend backfill session to UTC 2026-07-27 12:29:19 -07:00
docker fix(docker): fail the image build when the generated prisma engine paths drift off /opt/prisma (#35979) 2026-08-05 14:12:28 -07:00
enterprise fix(proxy): report has_more false on caller-scoped file list pages 2026-08-08 17:28:43 -07:00
examples chore: litellm oss staging (#31185) 2026-06-26 09:17:44 -07:00
gateway fix(docker): bake the componentized prisma engines at /opt/prisma so any uid can start (#35989) 2026-08-05 13:38:46 -07:00
helm docs(helm): replace the classic chart's 128Mi resource example with the documented 4Gi sizing (#35830) 2026-08-04 15:17:12 -07:00
litellm feat(proxy): add per-deployment keepalive_seconds SSE heartbeat to prevent load-balancer timeout on long streams (#34423) 2026-08-10 16:47:17 -07:00
litellm-proxy-extras feat(ptu): configure provisioned-throughput flat cost on a model deployment (#35341) 2026-08-10 09:51:16 -07:00
litellm-rust refactor(rust): make litellm-core the callable messages() SDK; drop the ai-gateway handler (#35044) 2026-07-29 13:41:31 -07:00
migrations fix(docker): bake prisma offline in the componentized migrations image (#35485) 2026-08-01 14:12:31 -07:00
packaging/homebrew feat(cli): per-agent lite claude / codex / opencode commands that wrap coding agents through the proxy (#29850) 2026-06-10 13:52:26 -07:00
scripts feat(proxy): add GET /v1/indexes to list vector store indexes (#36289) 2026-08-10 15:09:59 -07:00
terraform docs(terraform): describe the provider release as automatic 2026-08-10 14:54:16 -07:00
tests feat(proxy): add per-deployment keepalive_seconds SSE heartbeat to prevent load-balancer timeout on long streams (#34423) 2026-08-10 16:47:17 -07:00
ui feat(proxy): add per-deployment keepalive_seconds SSE heartbeat to prevent load-balancer timeout on long streams (#34423) 2026-08-10 16:47:17 -07:00
.dockerignore build(docker): build the Admin UI from source in a build-platform-pinned stage (#31130) 2026-06-25 23:41:08 -07:00
.env.example Add new model provider Novita AI (#7582) (#9527) 2025-05-12 21:49:30 -07:00
.git-blame-ignore-revs chore: ignore the mechanical lint and typing sweeps in git blame 2026-08-06 11:39:34 +00:00
.gitattributes feat(ui): generate dashboard API types from the proxy OpenAPI spec (#29816) 2026-06-05 17:20:01 -07:00
.gitguardian.yaml build: migrate packaging, CI, and Docker from Poetry to uv (#25007) 2026-04-09 11:46:23 -07:00
.gitignore fix(lint): measure the basedpyright budget gate in a gate-owned venv 2026-08-05 21:33:24 -07:00
.npmrc [Fix] CI/Tooling: Correct min-release-age value in .npmrc files 2026-04-29 19:49:27 -07:00
AGENTS.md docs: hand-written CLAUDE.md; point GEMINI.md and AGENTS.md at it (#29252) 2026-05-29 00:05:05 -07:00
ARCHITECTURE.md feat(litellm): add models and repository layers (#29686) 2026-06-06 20:59:33 -07:00
basedpyright-code-budget.json fix(reset_budget_job): atomic budget cascade with chunked reset scans (#36287) 2026-08-10 14:42:36 -07:00
CLAUDE.md docs: clarify the CLAUDE.md comment exceptions are any-of 2026-08-10 16:49:04 +00:00
codecov.yaml feat(jwt): fall back to DB team memberships when JWT has no team claims (#31356) 2026-07-06 17:17:10 -07:00
CONTRIBUTING.md chore(ci): retire daily OSS branches in favor of litellm_internal_staging 2026-07-20 11:38:52 -07:00
cosign.pub [Infra] Add release workflow and cosign public key 2026-03-31 14:30:27 -07:00
docker-compose.hardened.yml [Feature] Download Prisma binaries at build time instead of at runtime for Security Restricted environments (#17695) 2025-12-16 21:25:53 +05:30
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): fail the image build when the generated prisma engine paths drift off /opt/prisma (#35979) 2026-08-05 14:12:28 -07:00
GEMINI.md docs: hand-written CLAUDE.md; point GEMINI.md and AGENTS.md at it (#29252) 2026-05-29 00:05:05 -07:00
LICENSE refactor: creating enterprise folder 2024-02-15 12:54:13 -08:00
license_cache.json Add granian as a ASGI compliant web server. Provider better throughput stability, (#26027) 2026-05-21 19:08:37 -07:00
Makefile build(lint): rename make pre-commit to make check with a working-tree fallback 2026-08-08 03:25:35 -07:00
mcp_servers.json Add ScrapeGraph MCP server configuration (#18923) 2026-01-11 21:57:46 +05:30
model_prices_and_context_window.json Merge pull request #36403 from BerriAI/litellm_model_registry_deprecation_audit 2026-08-10 11:26:41 -07:00
model_prices_and_context_window.schema.json fix(pricing): regenerate model prices schema for flex long-context fields 2026-07-30 21:23:59 -07:00
osv-scanner.toml build(deps): bump pypdf to 6.15.0 to clear osv-scan 2026-08-09 13:09:28 +00:00
package-lock.json chore(deps): refresh dependency locks 2026-05-04 11:36:18 -07:00
package.json chore(deps): refresh dependency locks 2026-05-04 11:36:18 -07:00
policy_templates.json feat: Add Canadian PII protection (PIPEDA) (#22951) 2026-03-06 18:27:31 -08:00
prometheus.yml build(docker-compose.yml): add prometheus scraper to docker compose 2024-07-24 10:09:23 -07:00
provider_endpoints_support.json feat: add Meta Model API provider and muse-spark-1.1 (day-0) (#32701) 2026-07-09 20:45:27 -07:00
proxy_server_config.yaml fix(ci): let the E2E proxy accept the mock testing params its suite sends 2026-08-01 14:57:42 -07:00
pyproject.toml bump: litellm-enterprise 0.1.53 -> 0.1.54, litellm-proxy-extras 0.4.83 -> 0.4.84 2026-08-06 17:01:15 -07:00
pyrightconfig.json test(e2e): move Admin UI Playwright suite to tests/e2e/ui (#34196) 2026-07-22 19:43:10 +00:00
qa_sticky_session.sh feat(sandbox): reuse e2b container across requests when metadata.session_id is set (#31688) 2026-06-30 18:58:09 -07:00
README.md chore: keep it concise 2026-07-11 20:32:34 -07:00
render.yaml build(render.yaml): fix health check route 2024-05-24 09:45:28 -07:00
router_plugins.json feat(router): add router plugin reference catalog (#33746) 2026-07-17 18:46:20 +00:00
ruff-strict-budget.json fix(reset_budget_job): atomic budget cascade with chunked reset scans (#36287) 2026-08-10 14:42:36 -07:00
ruff-strict.toml feat(logging): add opt-in session_id and trace_id correlation to JSON log records via contextvars (#34418) 2026-08-10 10:40:13 -07:00
ruff.toml refactor(lint): graduate the 35 zero-violation strict rules into ruff.toml 2026-08-07 23:10:33 -07:00
schema.prisma feat(ptu): configure provisioned-throughput flat cost on a model deployment (#35341) 2026-08-10 09:51:16 -07:00
security.md docs(security): require a reproduction video for vulnerability reports (#30048) (#30063) 2026-06-09 14:59:50 -07:00
taplo.toml fix(agentcore): simplify agentcore streaming (#17141) 2026-01-19 05:20:24 -08:00
type-discipline-budget.json fix(reset_budget_job): atomic budget cascade with chunked reset scans (#36287) 2026-08-10 14:42:36 -07:00
uv.lock build(deps): bump pypdf to 6.15.0 to clear osv-scan 2026-08-09 13:09:28 +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 Deploy on AWS Deploy on GCP

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

PyPI Version GitHub Stars Y Combinator W23 Whatsapp Discord Slack CodSpeed

LiteLLM AI Gateway

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 — 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 sk-1234"}    # LiteLLM 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))

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)
ModelScope (modelscope)
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)
Pinstripes (pinstripes)
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.

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

Launch in AWS CloudShell — 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

Module page →

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

Open in Cloud Shell

Real 1-click. Opens Cloud Shell, clones this 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.

Module page →

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_KEY in your cloud's secret manager
  • A one-off migration job that runs prisma migrate deploy before the proxy starts
  • The same proxy_config surface 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

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

Backend

  1. Run make bootstrap
  2. Start proxy backend: uv run python litellm/proxy/proxy_cli.py

Frontend

  1. Navigate to ui/litellm-dashboard (dependencies were already installed w/ make bootstrap)
  2. Start dashboard: npm run dev

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