# Auth.md — Blocksize agent authentication

Public discovery at https://mcp.blocksize.info/mcp/server/ requires no credentials and cannot fetch paid data.
Use https://mcp.blocksize.info/openapi.json to discover HTTP operations and https://mcp.blocksize.info/.well-known/x402 for payment metadata.

## Authenticated connectors

Connect with the client-specific MCP URL and follow the client's OAuth sign-in flow:

| Client | MCP URL | Protected-resource metadata |
| --- | --- | --- |
| Claude | https://mcp.blocksize.info/anthropic/mcp/ | https://mcp.blocksize.info/.well-known/oauth-protected-resource/anthropic/mcp/ |
| Cursor | https://mcp.blocksize.info/cursor/mcp/ | https://mcp.blocksize.info/.well-known/oauth-protected-resource/cursor/mcp/ |
| OpenAI | https://mcp.blocksize.info/openai/mcp/ | https://mcp.blocksize.info/.well-known/oauth-protected-resource/openai/mcp/ |

Read the authorization server metadata advertised by the protected resource. Use its advertised
registration and authorization mechanisms; availability depends on deployment configuration.
The root OAuth metadata is a compatibility alias for the configured default connector.
Its resource identifies that connector, not the public homepage. Preserve resource/audience matching.

Eligible authenticated connector identities can receive starter credits. Public HTTP identity
headers cannot claim or spend them. Check credit balance before live calls.

## Direct HTTP payment

Paid HTTP routes use signed x402 v2 payments. An unpaid request to a paid route returns its
payment requirements. Read the current challenge for price, network, asset, and recipient.
Only authorize payment within the user's approved budget. Never put wallet secrets in requests.
Account plans are available by agreement.

Integration guide: https://mcp.blocksize.info/quickstart/remote-mcp
First live price: https://mcp.blocksize.info/quickstart/first-price
Support: https://mcp.blocksize.info/support

Account-linked agent registration is not enabled on this deployment. Use connector OAuth.