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Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.268 ·

MCP error messages now redact detail more precisely using server config

Error messages from MCP server connection and OAuth problems now clamp sensitive detail based on the specific server's setup

TierUnder the hoodhow much it should matter to you
Useful1my rating, 1 to 5
Signal1worth watching, 1 to 5
AreaMCPwhat it touches
KindInternal Changesin v2.1.268,
Group of 2 Under the hood

Error messages from MCP server connection and OAuth problems now clamp sensitive detail based on the specific server's setup

What

Errors from MCP (Model Context Protocol) server connections and OAuth flows now pass through helper functions that use the server's config object to decide how much detail to clamp or redact before showing or logging the error:

  • OAuth errors (a rejected custom redirectUri, a failed localhost fallback, or a failed OAuth completion) now route through this redaction logic, and a failed localhost OAuth fallback now throws an error instead of silently producing no result.
  • General MCP client reconnect/error-formatting calls now take the server's config alongside the error, letting the formatter tailor the message to the connection type, matching a 'detail withheld on this connection' pattern used for off-box connections.

Why

This avoids leaking sensitive connection detail in error messages while still giving useful, connection-appropriate context, and it fixes a case where a failed OAuth fallback used to fail silently instead of surfacing an error.

See this entry in the whole of v2.1.268 →

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