perf(mcp): skip preflight probe on reconnect#40548
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Review: PR #40548 -- perf(mcp): skip preflight probe on reconnect
Summary: Small, targeted change that skips the MCP preflight content-type probe when self._ready is already set (i.e., on reconnect).
What works well:
- The logic is correct: if the connection is already established (_ready.is_set()), there is no need to re-probe the content type.
- The change is minimal (one-line condition addition) and low-risk.
- The comment block above the code already documents the rationale for the probe, and this change is consistent with that intent -- probe on first connect only.
Considerations:
- No tests. While this is a small perf optimization that is difficult to test without mocking the ready event, a unit test verifying that _preflight_content_type is not called when _ready.is_set() would be ideal.
- The condition order is fine: short-circuit evaluation means self._ready.is_set() is not checked for SSE transports, which is correct.
Verdict: LGTM. Approve as-is; the lack of a test is acceptable given the nature of the change.
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Jun 10, 2026
…ready (NousResearch#40604) Closes NousResearch#40366. Salvaged from NousResearch#40548; re-verified on main, tightened, tested. Co-authored-by: mohamedorigami-jpg <mohamedorigami-jpg@users.noreply.github.com>
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Skip the MCP preflight content-type probe when reconnecting to a server that already connected successfully.
The preflight sends an initial HEAD request (which returns 405) followed by a GET (which returns 406). This adds about 3 seconds of network round-trip time on every reconnect with no actionable information, since the URL was already validated during the first connection.
The fix changes the condition from:
if config.get("transport") != "sse":to:
if config.get("transport") != "sse" and not self._ready.is_set():This ensures the preflight probe only runs on first connection, not on reconnects.
Closes #40366