Function: getAuthInfo()

function getAuthInfo(context: BaseContext, options?: GetAuthInfoOptions): McpAuthInfo;

Extracts the verified McpAuthInfo from an MCP request handler context (e.g. a tool callback's second argument), optionally enforcing per-tool scopes.

The bearer-auth middleware guarantees the auth info is present on every authenticated HTTP request, so a missing value indicates a wiring problem — for example, the MCP endpoint is not protected by requireBearerAuth, or a different token verifier than MCPAuth is in use.

Parameters

context

BaseContext

The request handler context provided by the MCP SDK.

options?

GetAuthInfoOptions

Optional per-tool authorization requirements.

Returns

McpAuthInfo

The verified auth info.

Example

import { getAuthInfo } from 'mcp-auth';

server.registerTool('whoami', { description: 'Get the current user' }, (ctx) => {
  const { subject, claims } = getAuthInfo(ctx);
  return { content: [{ type: 'text', text: JSON.stringify({ subject, claims }) }] };
});

server.registerTool('purge-notes', { description: 'Delete every note' }, (ctx) => {
  // Throws unless the token has the `notes:write` scope; the SDK surfaces the error to the
  // model as a tool error result.
  const { subject } = getAuthInfo(ctx, { requiredScopes: ['notes:write'] });
  // ...
});

Throws

if the context has no auth info, the auth info was not produced by MCPAuth#verifyAccessToken, or a required scope is missing.