ruvnet/ruflo · error

[mcp] routing preflight failed

Error message

[mcp] routing preflight failed

What it means

Log warning in resolveRouterTarget: resolving the router route/candidate model threw (route resolution or model lookup failure), so MCP routing preflight aborts and the request is handled without the MCP flow.

Source

Thrown at ruflo/src/ruvocal/src/lib/server/textGeneration/mcp/routerResolution.ts:103

			const { candidates } = resolveRouteModels(routeName, routes, fallbackModel);
			const primaryCandidateId = candidates[0];
			if (!primaryCandidateId || primaryCandidateId === fallbackModel) {
				runMcp = false;
			} else {
				const found = allModels?.find(
					(candidate) =>
						candidate.id === primaryCandidateId || candidate.name === primaryCandidateId
				);
				if (found) {
					targetModel = found;
					candidateModelId = primaryCandidateId;
				} else {
					runMcp = false;
				}
			}
		}
	} catch (error) {
		logger.warn({ err: String(error) }, "[mcp] routing preflight failed");
		runMcp = false;
	}

	return { runMcp, targetModel, candidateModelId, resolvedRoute };
}

View on GitHub (pinned to fa13ee4ad6)

Solutions

1. Check that the configured router model and endpoint are valid and reachable; preflight failure falls back to non-MCP routing, so fix the router configuration to restore MCP routing.

When it happens

Trigger: Thrown at ruflo/src/ruvocal/src/lib/server/textGeneration/mcp/routerResolution.ts:103 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ruvnet/ruflo@fa13ee4ad6 (2026-08-18). Data as JSON: /api/errors/01d40755ca90cb65. Report an issue: GitHub.