litellm/tests/test_litellm/responses/mcp
yucheng-berri f9f5c03884
fix(mcp): drop caller host and configured upstream headers from logged metadata (#36901)
* fix(mcp): drop caller host and configured upstream headers from logged metadata

The synthetic request that carries MCP client headers into
add_litellm_data_to_request forwarded the caller's Host header, and
Request.url is built from it, so a caller chose the proxy_server_request
url and the metadata endpoint that every logging callback records.

_upstream_credential_headers also only knew the configured client side
auth header and the x-mcp- prefix family, so a header name declared in
mcp_servers.<name>.extra_headers reached logging metadata in cleartext.
Those names are admin chosen, so no prefix rule can recognize them; read
them off the server registry instead. The header is still forwarded
upstream, which is what extra_headers is for. authorization is left out
because clean_headers already strips it and claiming it here would move
authenticated_with_header on the oauth passthrough config.

The Responses bridge tests stub the server manager, so their fakes gain
the registry accessor the sanitizer now reads.

* fix(mcp): drop caller host from the sanitized header mapping too

The synthetic request stopped forwarding host, but the parallel sanitizer
did not, so a forged hostname still reached the guardrail payload and the
list_tools spend row. Drop it there as well.

Exempt the configured identity headers from the upstream credential set.
get_user_from_headers resolves end user attribution off the same request
this module reconstructs, and it only fills end_user_id when auth left it
unset, so claiming user_header_name or a user_header_mappings name would
lose attribution on the MCP paths that authenticate upstream.

Drop the isinstance guard on extra_headers entries: the field is typed
list[str], so the check is dead and basedpyright scores it.

* fix(mcp): accept a bare user_header_mappings entry when exempting identity headers

get_internal_user_header_from_mapping and get_customer_user_header_from_mapping
both normalize a single mapping to a one element list, and config_settings.md
documents the key as a dict. Iterating the bare form yields its keys instead,
so the exemption silently matched nothing and an identity header also named in
an MCP server's extra_headers was dropped after all.
2026-08-14 17:21:07 -07:00
..
test_chat_completions_handler.py fix(mcp): roll up MCP tool spend to user counters and usage UI (#31576) 2026-07-02 08:16:39 -07:00
test_litellm_proxy_mcp_handler.py fix(mcp): drop caller host and configured upstream headers from logged metadata (#36901) 2026-08-14 17:21:07 -07:00
test_mcp_streaming_iterator.py fix(mcp): drop caller host and configured upstream headers from logged metadata (#36901) 2026-08-14 17:21:07 -07:00