MCP Server Authorization: Options and Limits

Use the MCP authorization specification for HTTP transport access, then add Grantex when tools must verify agent-specific delegated authority.

MCP authorization is optional and transport-specific. The current MCP authorization specification defines an OAuth-based flow for HTTP transports, including protected-resource metadata and authorization-server discovery. Stdio deployments use their host environment rather than that HTTP flow.

Two distinct Grantex packages

@grantex/mcp: manage Grantex through MCP tools

This MCP server exposes Grantex management operations to a configured MCP client. It uses a Grantex API key supplied by the host environment. It does not by itself turn every third-party MCP server into an authorized resource server.

{
  "mcpServers": {
    "grantex": {
      "command": "npx",
      "args": ["@grantex/mcp"],
      "env": { "GRANTEX_API_KEY": "set-in-the-host-environment" }
    }
  }
}

@grantex/mcp-auth@2.0.2: endpoint evaluation package

This package can be used to evaluate OAuth 2.1-style authorization endpoints and middleware. Version 2.0.2 is not the recommended production integration path.

Version 2.0.2 boundaryCurrent behaviorRequired response
Authorization-code storageNon-configurable, process-local storeUse one process for evaluation; do not horizontally scale
Consent UIconsentUi is discovery metadata onlyProvide and validate a host-owned consent experience
Code handoffThe Grantex code is not persisted for the token handlerUse a primary SDK flow until a corrected release is published
Revocation enforcementSignature and claim checks do not query live grant statePerform an online check or synchronize revocation data

Recommended production pattern today

  1. Implement the current MCP authorization specification with an established authorization server and maintained MCP SDK.
  2. Use @grantex/sdk@0.3.13 or direct JWKS validation for the Grantex agent grant.
  3. Validate issuer, audience, signature, expiry, principal, and required tool scope at the MCP resource server.
  4. Check or synchronize current grant state where revocation must take effect before token expiry.
  5. Log tool execution separately when you need an audit record; token verification alone is not an execution log.
npm install @grantex/sdk@0.3.13

// At the MCP tool boundary:
// 1. verify the signed grant token
// 2. require the tool's exact scope
// 3. check current state when revocation matters
// 4. invoke the tool only after authorization succeeds
Do not describe @grantex/mcp-auth@2.0.2 as drop-in, horizontally scalable, production-ready, or a complete hosted consent system.

Review the package boundary before choosing an MCP path

The release page is the source of truth for versions, runtimes, limitations, and workarounds.

MCP Auth limitations Release status

Technical review updated 12 July 2026.

Related implementation resources