René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"HTTP standard headers + x-mcp-header","articleBody":"Tracks: #2715\n\nThe shared encode/decode and `x-mcp-header` rule helpers used by both sides; server-side validation of inbound headers vs body.\n\n## What's in it\n\n- Encode/decode helpers for `Mcp-Method`/`Mcp-Name`/`Mcp-Param-*` (base64-sentinel, the `x-mcp-header` constraint rules).\n- Server: validate inbound headers vs body, reject mismatches — wired in by #2893.\n- Client emit is owned by #2894 (consumes these helpers).\n\n## Conformance\n\n- (helpers — scenarios are owned by _New HTTP serving path (modern + dual-era)_ server-side and _New Client (all-versions, low-level + high-level)_ client-side)\n- Together with #2893: `http-header-validation`, `http-custom-header-server-validation`\n- Together with #2894: `http-custom-headers`, `http-invalid-tool-headers`, `http-standard-headers`\n\n## Dependencies\n\n- Depends on: #2893\n\n## References\n\n- [Transports — headers](https://modelcontextprotocol.io/specification/draft/basic/transports/streamable-http#request-metadata)\n- [SEP-2243](https://github.com/modelcontextprotocol/modelcontextprotocol/pull/2243)\n- [sep-2243.yaml](https://github.com/modelcontextprotocol/conformance/blob/main/src/seps/sep-2243.yaml)\n- [python-sdk #2715](https://github.com/modelcontextprotocol/python-sdk/issues/2715)\n","author":{"url":"https://github.com/maxisbey","@type":"Person","name":"maxisbey"},"datePublished":"2026-06-17T11:12:14.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/2900/python-sdk/issues/2900"}