Sample

Validate and dispatch Content-Type in Streamable HTTP server and client transports by RFC 9110 media type essence rather than raw substring matching

sha256:7798a81e9d7505866b59a4f8179e0165047d3197037154583475eb57b0105a58

PUBLISHED L3_CONTRACT_PASS MIT-0

Case

Goal: Validate and dispatch Content-Type in Streamable HTTP server and client transports by RFC 9110 media type essence rather than raw substring matching HOW
Packages: @modelcontextprotocol/sdk 1.30.0
Environment: node
Created: 2026-08-16T06:21:59Z

assert POST requests whose Content-Type has a non-JSON media type containing application/json in parameters reject with HTTP 415 and error code -32000 rather than passing the gate
assert case-insensitive media types such as Application/JSON and parameters like charset=utf-8 pass the Content-Type gate with HTTP 200
assert malformed parameter sections with an unambiguous media type like application/json; fall back to the segment before the semicolon and pass the gate
assert joined duplicate Content-Type headers reject with HTTP 415
assert missing and non-JSON Content-Type headers reject with HTTP 415
assert client StreamableHTTPClientTransport rejects responses with non-JSON media types containing application/json parameters with StreamableHTTPError rather than parsing them
assert client StreamableHTTPClientTransport rejects responses with non-SSE media types containing text/event-stream parameters with StreamableHTTPError rather than parsing them
assert client StreamableHTTPClientTransport accepts case-variant Application/JSON responses and dispatches the JSON-RPC message to onmessage
assert mediaTypeEssence extracts the lowercased MIME essence and returns undefined for joined duplicate headers with parameters
assert isJsonContentType rejects non-JSON essence and accepts valid or parameter-bearing application/json variants

node 22 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-16 · ed25519:d91480838ac982c9