{"version":"2.1.311","anchor":"traceparent-fallback-and-mcp-sdk-docs-connector-flag","canonical_anchor":"traceparent-fallback-and-mcp-sdk-docs-connector-flag","heading":"Tracing headers can now be sent in more cases","tier":"notice","area":"Telemetry","scope":"org","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.311\/e\/traceparent-fallback-and-mcp-sdk-docs-connector-flag","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.311","markdown":"### Tracing headers can now be sent in more cases\n\nClaude Code now uses a second source for the traceparent tracing header, so it can be sent in cases where it was not sent before\n\n**Unclear.** What the second traceparent source is, and so which requests now carry the header, is not stated.\n\n**What**\n\nThe traceparent header is a label on a network request that lets tracing tools link that request to related ones. Before, Claude Code added it only under one condition, which `CLAUDE_CODE_PROPAGATE_TRACEPARENT` could satisfy. Now, if that first source gives no value, Claude Code tries a second source, so the header can be sent even when the earlier condition is not met.\n\nInformation Claude Code keeps about MCP tools also gained a new marker for an SDK documentation connector.\n\n**Why**\n\nTrace headers may now be sent on more requests. This is worth knowing if you watch which headers Claude Code sends.\n\n- Area: Telemetry\n- Names: `CLAUDE_CODE_PROPAGATE_TRACEPARENT`\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 1\/5\n- Scope: org\n- Heads-up: no"}