modelcontextprotocol / modelcontextprotocol/typescript-sdk

Better CORS defaults for SSE transport

Open
#143 6 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

enhancement needs decision P2
Dominant language
TypeScript
Stars
13.4k
Forks
2.2k
Avg merge
3d 15h
Merged PRs (30d)
4

Description

It's likely that most MCP servers accessible over SSE should be contactable by frontend web applications, which means the right CORS headers need to be set. The SDK should likely opt-in to this by default, with an opt-out available.

See also https://github.com/modelcontextprotocol/python-sdk/issues/187.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by tracing the SSE transport implementation and review the related Python SDK issue #187 for context on the expected CORS behavior. Define what headers should be enabled by default and how callers opt out; the work is done when that behavior is implemented and covered by the relevant transport tests.

Written by the indexing model from the issue text.

Assessment

Tech stack
typescript
Domain
api, backend, networking
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.