feat(core): Emit low cardinality mcp.server span names - #23569
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With span streaming enabled, resource methods are named after the method alone, so the client-supplied resource URI stays out of the span name. Tool and prompt names are unchanged. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013bjBXkGkJo8eL8hkz48byi
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LGTM! Since we briefly talked yesterday that this "breaks" the MCP dashboard, I stand corrected: The dashboard I had in mind groups by span description which still has a rule ton infer the URI based on the mcp.resource.uri which we send. So, name changes are not affecting this.
And even if we'd not be consistent with the description, it's probably not the end of the world. So good to merge from my PoV!
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| "@langchain/core": "^0.3.80", | ||
| "@langchain/openai": "^0.5.0", | ||
| "@langchain/langgraph": "^0.2.32", | ||
| "@modelcontextprotocol/client": "2.0.0", |
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This matches our other mcp apps, I just followed suite tbh. We could loosen it.
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Makes sense. Loosening it wouldn't be a bad idea though.- not a PR blocker
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Will do in a follow-up.
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## What The MCP v2 test dependencies (`@modelcontextprotocol/client`, `@modelcontextprotocol/node`, `@modelcontextprotocol/server`) now use `^2.0.0` instead of an exact `2.0.0`, across the node integration tests and the `node-express-mcp-v2` and `cloudflare-mcp` e2e apps. `cloudflare-mcp-agent` keeps its exact `@modelcontextprotocol/sdk` pin, because `agents` depends on that specific version. ## Why The exact pins were copied from app to app rather than chosen, and nothing here needs a frozen version. Follow-up to #23569. Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
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What
With span streaming enabled,
mcp.serverspans for resource methods are named after the method alone (resources/read), instead of appending the resource URI. Tool and prompt names are unchanged, since those come from a bounded registry.Why
Span names must be low cardinality when span streaming is enabled, and a resource URI is supplied by the client. The URI remains available on the
mcp.resource.uriattribute.Closes: #23529