Zuplo
Model Context Protocol

Learn MCP

Guides to MCP authentication, and fixes for the errors MCP clients report.

Your MCP server one of these, behind one of those

MCP clients

What is calling your server

Claude Code Claude custom connectors ChatGPT connectors Cursor VS Code

Hosts and gates

Where it runs, and what sits in front

Vercel Netlify Kubernetes Azure Container Apps AWS API Gateway Cloudflare Access

Identity providers

Who issues the credential

Microsoft Entra ID Okta Auth0 Keycloak Amazon Cognito
Topics

Where to start

Learn how MCP authentication works, and how to fix the errors clients report.

Topic MCP authentication How callers prove who they are to a remote MCP server, with working code for each method. Methods covered Anthropic-hosted agents API key AWS IAM (SigV4) Client credentials (M2M) Google Cloud IAM Microsoft Entra ID mTLS OAuth 2.1 See all methods
Reference Errors clients report Look up the error your client printed, and fix it on your platform. Includes Authorization with the MCP server failed Couldn't reach the MCP server Dynamic Client Registration not supported and 8 more See all errors

Ship MCP servers without rebuilding auth

A gateway in front of your MCP servers handles discovery, audience binding, and token validation once — for every server and every client.

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