mcpauth

mcpauth vs. Auth0

Auth0 is one of the most established identity platforms on the market, and it has responded to the rise of MCP with “Auth for AI Agents,” part of a broader “Auth for GenAI”umbrella. If you’re evaluating how to add OAuth to an MCP server, here is an honest comparison of where each tool fits.

The short version

mcpauth is a purpose-built OAuth 2.1 authorization server for MCP servers: Dynamic Client Registration (RFC 7591) and discovery (RFC 8414) out of the box, an SDK that wraps the official @modelcontextprotocol/sdk auth middleware, and nothing else to configure. Auth0’s Auth for AI Agents is a feature area inside a full CIAM (customer identity and access management) platform — MCP support sits alongside RAG authorization, agent-to-agent auth, Token Vault, and the rest of Auth0’s general-purpose identity product. Both are real, credible ways to solve this problem. Which one is right for you mostly comes down to whether MCP OAuth is the only auth problem you have, or one of several.

What Auth0 brings to the table

Auth0 is a mature, widely deployed identity platform, and that maturity is real value if you’re already using it or need more than MCP auth:

  • Auth for GenAI is broader than MCP.Beyond authorizing MCP tool calls, the umbrella also covers authorization for RAG pipelines, agent-to-agent auth, and a Token Vault for storing third-party API credentials an agent needs. If your AI product has auth needs beyond “secure my MCP server,” that breadth is genuinely useful.
  • A real startup program. Auth0 offers a free B2B tier with up to 100,000 monthly active users through its startup program — a strong deal for a funded or growing team that expects to need enterprise-grade identity features later.
  • One platform for all your auth.If your application already uses Auth0 for its regular user login, and your MCP server is one more surface on top of an app you’ve already built on Auth0, staying on a single platform has obvious operational advantages.

Where mcpauth is a better fit

  • Built for exactly one thing.mcpauth doesn’t ask you to adopt a CIAM platform to get OAuth working on an MCP server. There’s no broader identity product to configure around it — you register a project, drop in the SDK middleware, and your MCP server is protected.
  • Dynamic Client Registration is the whole point, not a feature among many. RFC 7591 (client registration) and RFC 8414 (discovery) are what let any MCP client — Claude, another agent, a future client no one has built yet — connect to your server without you manually registering it first. That spec detail is core to how mcpauth is built, rather than one capability layered onto a general-purpose identity platform.
  • Minutes, not a platform migration. Because mcpauth has no other surface area to learn, integration isnpm install getmcpauthand one middleware call in front of your MCP routes.
  • Straightforward, transparent pricing. Free tier to start, then a flat $29/mo with a clear per-token overage — no sales call required to find out what it costs at your scale.

Integration example

Protecting an MCP server with mcpauth is a single middleware call:

import express from "express";
import { mcpAuth } from "getmcpauth";

const app = express();

app.use(
  "/mcp",
  mcpAuth({
    registrationSecret: process.env.MCPAUTH_SECRET!,
  })
);

The middleware wraps the official @modelcontextprotocol/sdk bearer-auth verifier, so unauthenticated or invalid requests are rejected with a spec-correct 401 before they ever reach your MCP handlers, and successful token checks are cached in-process (30 second default TTL) so a chatty agent conversation isn’t making a network round-trip on every tool call.

When to choose which

Choose mcpauthif MCP OAuth is the problem in front of you today, and you’d rather not onboard a full CIAM platform to solve it. It’s built specifically around DCR and the MCP authorization spec, and there’s no broader product to configure your way around.

Choose Auth0if you need auth for more than MCP — RAG authorization, agent-to-agent auth, general application login, or you’re already running on Auth0 and want one platform for all of it. Its startup program is also worth a look if you expect to need enterprise identity features as you grow.

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