modelcontextprotocol / modelcontextprotocol/python-sdk
Does same-origin redirect enforcement break MCP servers behind a reverse proxy?
Nobody has claimed this yet.
- Dominant language
- Python
- Stars
- 24.3k
- Forks
- 4k
- Avg merge
- 1d 1h
- Merged PRs (30d)
- 31
Description
Reading the v2.2.0 release notes: the HTTP client now fails redirects with MCPError unless the target is same-origin. For self-hosted setups this seems like it could bite people running an MCP server behind something like Caddy or nginx — e.g. an HTTP→HTTPS redirect, or a redirect from a bare port to a subpath, which often lands on a different-looking origin even though it's the same server.
The changelog doesn't say whether there's a way to allowlist additional origins for these cases, or whether the guidance is simply "don't let your reverse proxy redirect, terminate TLS and proxy_pass directly." Is there a documented escape hatch, or is this an intentional hard stop meant to force removing redirects from self-hosted deployments entirely? A line in the migration notes about the reverse-proxy case would save people a confusing debugging session when their server that worked in 2.1.x suddenly throws on upgrade.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the v2.2.0 release notes and the HTTP client redirect enforcement described in the issue. Verify whether additional origins can be allowlisted and how HTTP-to-HTTPS or subpath redirects behave behind a reverse proxy. Update the migration notes with the confirmed escape hatch or deployment guidance for self-hosted MCP servers.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- nginx, python
- Domain
- documentation, networking
- Issue type
- Documentation
- Difficulty
- 2/5
- Estimated time
- 1-3 hours
- Activity status
- Active
- Clarity
- Mostly clear
- Newbie friendliness
- 64/100