ChangelogIntegrations & LibrariesMCP serverStandard protocol negotiation errorsPublished: August 12, 2026v2.29.1Copy entryFixesProtocol negotiation: Returns the standard error response when an MCP client requests an unsupported protocol version.Previous ChangelogCORS origin tools and safer document inputsAugust 12, 2026MCP serverNext ChangelogNode 22+ ESM-only support and refined upload, proxy, and error handlingAugust 12, 2026JavaScript Client