Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.51 Home All releases olderv2.1.50 v2.1.52newer
Claude Code v2.1.51

MCP OAuth Improvements

  • Step-up scopes are now persisted across auth revocations, preventing users from having to re-authorize expanded permissions
  • OAuth discovery state (authorization server URL, resource metadata) is cached to avoid repeated discovery requests
  • New skipBrowserOpen option for headless environments — logs the authorization URL instead of opening a browser
  • preserveStepUpState flag during MCP authentication prevents loss of elevated permissions
Evidence

"Persisted step-up scope:" log message, "Saving discovery state" log message (search for "Persisted step-up scope")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.51 →