You'll noticeTier: how much it should matter to you
3Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
MCPArea: what it touches
New FeaturesKind: in v2.1.248,
New FeaturesSection of the release
What
Failures from MCP servers and OAuth flows no longer echo raw exception text when the session lives off your machine. Reconnect, enable and disable actions in the /mcp server views, MCP calls, MCP authentication, MCP OAuth callback URLs and the Claude OAuth callback all return a redacted message instead, and the real error text is written to the local debug log. A normal local run is unchanged and still shows the full error.
Details
Covers the stdio and remote server detail views and the reconnect action, which reports Error reconnecting to ${St(o)} (detail withheld on this connection).
Control-channel responses substitute (detail withheld) for the underlying message.
Redaction over the control channel is gated on the environment variable CLAUDE_CODE_ENVIRONMENT_KIND being set to bridge and on the connection persisting off the machine; otherwise the raw error is passed through as before.
The /mcp view redaction has no flag of its own and follows solely from whether the session persists off-box.
Server names, messages and modes are sanitized before being interpolated into any response.
MCP and OAuth failures are routed through one shared error responder rather than stringifying the exception at each call site.
Evidence
Error reconnecting to ${St(o)} (detail withheld on this connection)., (detail withheld)
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Added sinceA small documentation edit on Channels reference touched a line naming /mcp after this was published.* **`curl` succeeds but nothing reaches Claude**: run `/mcp` in your session to check the server's status. A `failed` status usually means a dependency or import error in your server file. To see the stderr trace, restart with `claude --de…channels-referencesee the edit
Confirmed sinceAnthropic's documentation has since written up /mcp, on Third party connectors with remote MCP.**MCP server URL**: the HTTPS address where the server accepts MCP requests, for example `https://mcp.example.com/mcp`. After you continue, Claude checks the URL and pre-fills the authentication settings it detects, marked "Detected."connectors/custom/remote-mcpsee the edit
How sure we are
Two sources agreeTwo things we can check say the same as this entry.
Anthropic's documentation agreesAnthropic's documentation has since written up /mcp, on Third party connectors with remote MCP.
Anthropic's release notes agreeFixed /mcp listing a project .mcp.json entry that declares the claude.ai connector type under the trusted "claude.ai" heading; it now…
