litellm/tests
Sameer Kankute 466f06df6d
fix(mcp): surface upstream 401 for token-forwarding MCP servers (#27847)
* fix(mcp): surface upstream 401 for token-forwarding MCP servers

For MCP servers configured with extra_headers: [Authorization], the gateway
forwards the client token directly to the upstream. When that token is rejected
(expired or invalid) the upstream returns 401, but the MCP SDK starts the SSE
stream with 200 OK before calling handlers, so the 401 can't be returned
mid-stream.

Fix: add a pre-flight httpx probe in handle_streamable_http_mcp — before the
SDK opens the session — so the gateway can still return HTTP 401 with
WWW-Authenticate: Bearer authorization_uri=<gateway-discovery-url> when the
upstream rejects the token. The probe fails-open (returns 200) on network
errors so a transient hiccup does not block valid requests.

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

* fix(mcp): parallelize pre-flight auth probes and use HEAD to avoid side effects

- Extract forwarded_auth outside the pass-through server loop (was called N times for the same scope value)
- Gather all upstream auth probes concurrently with asyncio.gather instead of sequentially; eliminates N×5 s worst-case latency
- Switch probe from POST+initialize JSON-RPC body to HEAD request; HEAD carries the Authorization header so the upstream rejects invalid tokens with 401 but never allocates a session or writes an audit entry

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

* fix(mcp): use get_async_httpx_client in _probe_upstream_auth

Replaces bare httpx.AsyncClient with the project-standard
get_async_httpx_client(httpxSpecialProvider.MCP) to satisfy the
ensure_async_clients_test code coverage check and avoid the +500 ms
per-request overhead of creating a new client on every probe call.

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

* refactor(mcp): extract pre-flight probe into _check_passthrough_upstream_auth

Moves the parallel upstream auth probe logic out of
handle_streamable_http_mcp into a dedicated helper to satisfy
Ruff PLR0915 (Too many statements > 50).

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

* fix(mcp): gate pre-flight probes on authorized server set to prevent bypass

_check_passthrough_upstream_auth was resolving user-supplied server names
directly before authorization ran, letting any permitted LiteLLM key
trigger an upstream HEAD probe to a server it was not allowed to use.

Changes:
- Call _get_allowed_mcp_servers inside the helper so only servers the
  caller's key is authorized for are probed.
- Move the call site to after toolset scoping so the auth context is
  fully resolved before the probe list is built.
- Thread user_api_key_auth into the helper signature (replaces the raw
  mcp_servers name list).

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

* Add async HTTP HEAD support

Co-authored-by: Yassin Kortam <yassin@berri.ai>

* fix(mcp): use Scope type annotation in _get_forwarded_auth_from_scope

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

* Fix MCP upstream auth probe method

Co-authored-by: Yassin Kortam <yassin@berri.ai>

* Remove unused AsyncHTTPHandler head method

Co-authored-by: Yassin Kortam <yassin@berri.ai>

* fix(mcp): exclude has_client_credentials servers from pre-flight auth probe

_prepare_mcp_server_headers skips caller Authorization when the server
uses OAuth client-credentials (M2M), but the pre-flight probe was still
selecting those servers and forwarding the caller's raw token in the HEAD
request. Exclude servers with has_client_credentials from the probe list
to match the actual downstream header-preparation logic.

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

* fix(mcp): propagate upstream 403 as 403, not 401 with WWW-Authenticate

Per RFC 9110, 401 means "go get new credentials." Mapping an upstream 403
to a gateway 401 causes OAuth clients to restart the authorization flow,
obtain a fresh token with identical scopes, hit 403 again, and loop
indefinitely.

401 from upstream → gateway 401 + WWW-Authenticate (re-authorize)
403 from upstream → gateway 403 (no WWW-Authenticate hint)

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

* fix(mcp): skip auth probe when Authorization may be the LiteLLM proxy key

The pre-flight upstream probe must not forward the caller's Authorization
header when it could itself be the LiteLLM proxy API key. Restrict the
probe to requests that supply x-litellm-api-key explicitly — only then is
the Authorization header unambiguously the upstream OAuth token the
caller wants forwarded.

* Fix MCP ASGI HTTPException propagation

Co-authored-by: Yassin Kortam <yassin@berri.ai>

* fix(mcp): use public AsyncHTTPHandler.post() in auth probe

Use AsyncHTTPHandler.post() and catch httpx.HTTPStatusError explicitly so
the 401/403 we want to surface is not silently swallowed by the broad
fail-open except Exception block. Avoids reaching into the handler's
private client attribute, which would silently regress to fail-open if
AsyncHTTPHandler is ever refactored.

* Fix MCP auth probe tests

Co-authored-by: Yassin Kortam <yassin@berri.ai>

* test(mcp): add coverage for httpx.HTTPStatusError path in auth probe

AsyncHTTPHandler.post() calls raise_for_status() internally, so a real
upstream 401/403 lands as httpx.HTTPStatusError. Add a test that exercises
that specific exception path so a regression that swallows the error in
the broad fail-open except Exception would be caught.

---------

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Yassin Kortam <yassin@berri.ai>
Co-authored-by: claude-bot <claude-bot@anthropic.com>
2026-05-13 12:03:36 -07:00
..
agent_tests style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
audio_tests [Test] Tests: Stop parametrizing API keys into pytest test IDs (#27249) 2026-05-05 17:21:18 -07:00
basic_proxy_startup_tests build: migrate packaging, CI, and Docker from Poetry to uv (#25007) 2026-04-09 11:46:23 -07:00
batches_tests fix(ci): unbreak realtime + bedrock batch tests (#27690) 2026-05-11 18:08:14 -07:00
benchmarks Add CodSpeed performance benchmarks (#23676) 2026-03-14 18:44:36 -07:00
code_coverage_tests feat(audio_transcription): add NVIDIA Riva STT provider (#27185) 2026-05-05 17:17:51 -07:00
documentation_tests style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
enterprise fix(tests): use canonical litellm_enterprise import path (#27699) 2026-05-12 12:32:57 -07:00
guardrails_tests test: add 24hr Redis-backed VCR cache to additional test suites (#27159) 2026-05-05 15:13:31 -07:00
image_gen_tests fix(tests): drop dall-e-only test classes; route live image tests via gpt-image-1 2026-05-12 16:55:19 -07:00
litellm Add new chat model metadata (#27313) 2026-05-06 15:15:21 -07:00
litellm-proxy-extras style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
litellm_core_utils Merge branch 'litellm_internal_staging' into litellm_staging_03_22_2026 2026-04-20 19:56:00 +05:30
litellm_utils_tests feat(proxy): skip disable_background_health_check models on GET /health when flag set (#27716) 2026-05-13 09:49:05 -07:00
llm_responses_api_testing test: add 24hr Redis-backed VCR cache to additional test suites (#27159) 2026-05-05 15:13:31 -07:00
llm_translation fix(ci): unbreak realtime + bedrock batch tests (#27690) 2026-05-11 18:08:14 -07:00
load_tests style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
local_testing fix(tests): drop dall-e-only test classes; route live image tests via gpt-image-1 2026-05-12 16:55:19 -07:00
logging_callback_tests Merge pull request #27222 from BerriAI/litellm_s3AuditParams 2026-05-07 12:49:03 -07:00
mcp_tests feat: litellm shin agent oss staging 05 10 2026 (#27631) 2026-05-11 20:31:43 -07:00
multi_instance_e2e_tests
ocr_tests [Fix] Tests: Reduce VCR cassette bloat and fix multipart caching 2026-05-07 11:54:19 -07:00
old_proxy_tests/tests fix: cleanup tests 2026-03-30 16:24:35 -07:00
openai_endpoints_tests style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
otel_tests fix(tests): swap dall-e to gpt-image-1 after openai deprecation 2026-05-12 16:55:18 -07:00
pass_through_tests chore(deps): refresh dependency locks 2026-05-04 11:36:18 -07:00
pass_through_unit_tests test: add 24hr Redis-backed VCR cache to additional test suites (#27159) 2026-05-05 15:13:31 -07:00
proxy_admin_ui_tests chore(deps): refresh dependency locks 2026-05-04 11:36:18 -07:00
proxy_e2e_anthropic_messages_tests style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
proxy_security_tests style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
proxy_unit_tests feat(proxy): skip disable_background_health_check models on GET /health when flag set (#27716) 2026-05-13 09:49:05 -07:00
router_unit_tests test: replace dall-e-3 with gpt-image-1 in health check and router tests (#27813) 2026-05-12 21:23:52 -07:00
scim_tests
search_tests test: add 24hr Redis-backed VCR cache to additional test suites (#27159) 2026-05-05 15:13:31 -07:00
spend_tracking_tests chore(proxy): guard sensitive public endpoints 2026-04-30 11:52:47 -07:00
store_model_in_db_tests style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_litellm fix(mcp): surface upstream 401 for token-forwarding MCP servers (#27847) 2026-05-13 12:03:36 -07:00
unified_google_tests test: add 24hr Redis-backed VCR cache to additional test suites (#27159) 2026-05-05 15:13:31 -07:00
vector_store_tests fix: drop milvus dbName and partitionNames from MILVUS_OPTIONAL_PARAMS 2026-04-30 11:51:32 -07:00
windows_tests style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
__init__.py
_flush_vcr_cache.py tests(vcr): isolate cassette redis to CASSETTE_REDIS_URL 2026-05-01 12:32:59 -07:00
_vcr_conftest_common.py [Fix] Tests: Reduce VCR cassette bloat and fix multipart caching 2026-05-07 11:54:19 -07:00
_vcr_redis_persister.py test: add 24hr Redis-backed VCR cache to additional test suites (#27159) 2026-05-05 15:13:31 -07:00
eval_swe_bench.py Prompt Compression - add it to the proxy (#25729) 2026-04-20 15:08:00 -07:00
gettysburg.wav
large_text.py
openai_batch_completions.jsonl
README.MD
test_budget_management.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_callbacks_on_proxy.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_config.py
test_debug_warning.py
test_default_encoding_non_root.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_end_users.py
test_entrypoint.py
test_fallbacks.py
test_gpt5_azure_temperature_support.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_health.py fix(tests): swap dall-e to gpt-image-1 after openai deprecation 2026-05-12 16:55:18 -07:00
test_keys.py fix(tests): swap dall-e to gpt-image-1 after openai deprecation 2026-05-12 16:55:18 -07:00
test_litellm_proxy_responses_config.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_logging.conf
test_models.py test: replace test_add_and_delete_models integration test with mock 2026-03-30 21:30:57 -07:00
test_new_vector_store_endpoints.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_openai_endpoints.py fix(tests): swap dall-e to gpt-image-1 after openai deprecation 2026-05-12 16:55:18 -07:00
test_organizations.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_otel_thread_leak.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_passthrough_endpoints.py
test_presidio_latency.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_proxy_server_non_root.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_ratelimit.py [Fix] test_ratelimit: skip over-limit cases that race with background RPM tracking 2026-04-11 13:08:59 -07:00
test_resource_cleanup.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_service_logger_otel.py
test_spend_logs.py
test_team.py style: run black formatter on files from main merge 2026-04-17 13:02:59 -07:00
test_team_logging.py test: cleanup dead tests 2026-03-28 20:49:02 -07:00
test_team_members.py
test_users.py Fix: tag budget reset must drop stale management-cache entry (#27568) 2026-05-10 00:18:55 +00:00

In total litellm runs 1000+ tests

[02/20/2025] Update:

To make it easier to contribute and map what behavior is tested,

we've started mapping the litellm directory in tests/test_litellm

This folder can only run mock tests.