{"version":"2.1.221","anchor":"mcp-http-auth-errors-matched-on-both-code-and-errorcode","canonical_anchor":"mcp-http-auth-errors-matched-on-both-code-and-errorcode","heading":"MCP HTTP auth errors matched on both code and errorCode","tier":"internal","area":"MCP","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.221\/e\/mcp-http-auth-errors-matched-on-both-code-and-errorcode","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.221","markdown":"### MCP HTTP auth errors matched on both code and errorCode\n\nClaude recognizes MCP login failures more reliably, so auth errors are handled instead of retried blindly.\n\n**What**\n\nThe MCP SDK moved to string error codes such as CLIENT_HTTP_AUTHENTICATION carried on a `code` property, and the app's classifiers were widened to match.\n\n**Details**\n\n- The 401 and 403 classifiers accept either `code` or `errorCode`.\n- The retry predicate special-cases the typed HTTP error's status instead of string-matching \"Server returned 403 after trying upscoping\".\n\n**Evidence**\n\n`ClientHttpForbidden`\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 0\/5"}