René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Capabilities API + server/discover handler","articleBody":"Tracks: #2804 #2793\n\nLet servers/clients actually configure what they advertise (currently pre-computed), surface the `extensions` map, and provide the default `server/discover` handler that returns it.\n\n## What's in it\n\n- Rework `get_capabilities()` / `InitializationOptions` so capabilities are configurable, not pre-computed.\n- The `extensions` capability map surfaced on both client and server.\n- Default `server/discover` handler: capabilities, serverInfo, supportedVersions, instructions (cache-hint defaults from #2899).\n\n## Conformance\n\n- (the discover checks live inside `server-stateless`)\n- Together with _Backwards compatibility \u0026 version negotiation_, _New HTTP serving path (modern + dual-era)_, _subscriptions/listen_, _Context object (layered, per-request)_: `server-stateless`\n\n## Dependencies\n\n- Depends on: #2892\n\n## References\n\n- [server/discover](https://modelcontextprotocol.io/specification/draft/server/discover)\n- [SEP-2133](https://github.com/modelcontextprotocol/modelcontextprotocol/pull/2133)\n- [SEP-2575](https://github.com/modelcontextprotocol/modelcontextprotocol/pull/2575)\n","author":{"url":"https://github.com/maxisbey","@type":"Person","name":"maxisbey"},"datePublished":"2026-06-17T11:12:01.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/2896/python-sdk/issues/2896"}