Custom Provider

import { MCPServer } from "mcp-use";
import {
  createJwtVerifier,
  oauthCustomProvider,
  type OAuthAuthInfo,
  type OAuthMetadata,
} from "mcp-use/oauth";

const issuer = "https://auth.example.com";

const oauthMetadata = {
  issuer,
  authorization_endpoint: `${issuer}/oauth/authorize`,
  token_endpoint: `${issuer}/oauth/token`,
  registration_endpoint: `${issuer}/oauth/register`,
  response_types_supported: ["code"],
  grant_types_supported: ["authorization_code", "refresh_token"],
  code_challenge_methods_supported: ["S256"],
} satisfies OAuthMetadata;

type AppUser = {
  id: string;
  email?: string;
  organizationId?: string;
};

const server = new MCPServer({
  name: "custom-auth-server",
  version: "1.0.0",
  oauth: oauthCustomProvider<AppUser>({
    oauthMetadata,

    createTokenVerifier(resource) {
      return createJwtVerifier({
        issuer,
        jwksUrl: new URL(`${issuer}/.well-known/jwks.json`),
        resource,
      });
    },

    mapAuthInfo(authInfo: OAuthAuthInfo) {
      const payload = authInfo.extra?.payload as Record<string, unknown>;
      if (typeof payload.sub !== "string") {
        throw new Error("Verified token is missing sub");
      }

      return {
        user: {
          id: payload.sub,
          email: typeof payload.email === "string" ? payload.email : undefined,
          organizationId:
            typeof payload.organization_id === "string"
              ? payload.organization_id
              : undefined,
        },
        payload,
        permissions: Array.isArray(payload.permissions)
          ? payload.permissions.filter(
              (value): value is string => typeof value === "string",
            )
          : [],
      };
    },
  }),
});

export default server;