OAuth Flow Initialization Failure with MCP Server Endpoint

Bug Description
I can't figure out how to get claude code to start an OAuth flow with my MCP server. It is at https://mcp.hello-beta.net/mcp

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 1.0.43
• Feedback ID: c7a44799-96a9-44c2-a7a6-7bd9f50c0ded

Errors

[{"error":"Error: Command failed: security find-generic-password -a $USER -w -s \"Claude Code\"\nsecurity: SecKeychainSearchCopyNext: The specified item could not be found in the keychain.\n\n    at genericNodeError (node:internal/errors:983:15)\n    at wrappedFn (node:internal/errors:537:14)\n    at checkExecSyncError (node:child_process:882:11)\n    at execSync (node:child_process:954:15)\n    at ED (file:///Users/dick/.nvm/versions/node/v22.14.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:702:3921)\n    at file:///Users/dick/.nvm/versions/node/v22.14.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:623:9038\n    at Q (file:///Users/dick/.nvm/versions/node/v22.14.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:526:13327)\n    at hJ (file:///Users/dick/.nvm/versions/node/v22.14.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:623:8184)\n    at S_ (file:///Users/dick/.nvm/versions/node/v22.14.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:623:7265)\n    at NB (file:///Users/dick/.nvm/versions/node/v22.14.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:623:11432)","timestamp":"2025-07-06T16:09:12.854Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.0: all messages must have non-empty content except for the optional final assistant message\"}}\n    at C6.generate (file:///Users/dick/.nvm/versions/node/v22.14.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:1317:12578)\n    at bq.makeStatusError (file:///Users/dick/.nvm/versions/node/v22.14.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:1334:2100)\n    at bq.makeRequest (file:///Users/dick/.nvm/versions/node/v22.14.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:1334:5311)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)","timestamp":"2025-07-06T16:09:32.347Z"}]