{"version":"2.1.268","anchor":"mcp-oauthauth-error-messages-now-pass-through-a-redaction-h","canonical_anchor":"mcp-oauthauth-error-messages-now-pass-through-a-redaction-h","heading":"MCP OAuth\/auth error messages now pass through a redaction helper","tier":"internal","area":"MCP","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.268\/e\/mcp-oauthauth-error-messages-now-pass-through-a-redaction-h","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.268","markdown":"### MCP OAuth\/auth error messages now pass through a redaction helper\n\nMCP OAuth error messages are now run through a redaction helper before being logged or sent\n\n**What**\n\nWhen Claude Code's MCP (Model Context Protocol, the system that lets Claude talk to external tool servers) authentication flow fails, the error text it produces is now built through a new redaction helper before it is logged or sent back over the control channel. This applies to errors from the authentication step, the OAuth callback URL handling, and the redirect-URI fallback logging.\n\n**Why**\n\nThis reduces the chance that sensitive details (such as tokens or internal URLs) leak into logs or error messages shown to the user when an MCP server's authentication fails.\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 1\/5"}