---
title: "Learn MCP - Zuplo"
description:
  "Reference material for the Model Context Protocol: how authentication works
  across methods, SDKs and identity providers. Learn how it works in production."
canonicalUrl: "https://zuplo.com/learn/mcp"
sourceUrl: "https://zuplo.com/learn/mcp"
pageType: "other"
generatedAt: "2026-09-04"
---

# Learn MCP

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

An MCP server sits behind three axes that these pages cover:

- **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

## Customer story

### Finsolutia launched an MCP server in hours

Finsolutia is a mortgage servicer, about 400 people across Lisbon, Oporto and
Madrid. Their REST APIs already had OpenAPI descriptions, so the MCP server was
generated from those rather than written by hand. One company's result, not a
trend.

> We didn't touch a line of code, it's just plug and play. The results were very
> surprising, in just a couple of hours we had a great result and a fully
> working MCP Server.
>
> — Miguel Madeira, CTO & Co-Founder, Finsolutia

- From zero to MCP deployment: **< 24 hours**
- Code changes: **0**

[Read the Finsolutia case study](/customers/finsolutia)

## Topics — Where to start

### 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](/learn/mcp/authentication)

### Errors clients report

Look up the error your client printed, and fix it on your platform.

Includes:

- `[mcp-sdk] excluding tool '<name>' from tools/list: invalid x-mcp-header declaration`
- `Authorization with the MCP server failed`
- `Couldn't reach the MCP server`
- and 10 more

[See all errors](/learn/mcp/errors)

### Glossary

What each term means, cited to the RFC or specification section it comes from.

Acronyms covered: ASM, CIMD, DCR, ID-JAG, MRTR, PKCE, PRM, SEP

[Look up a term](/learn/mcp/glossary)

### Client and provider compatibility

What each MCP client puts on the wire, and what each identity provider supports.
Every cell cites a source.

Clients covered: claude.ai, ChatGPT connectors and apps, Claude Code, Claude
Agent SDK, Claude Managed Agents, Messages API MCP connector, OpenAI Responses
API mcp tool, Microsoft Copilot Studio, Codex CLI, Gemini CLI, and 12 more

[See both matrices](/learn/mcp/compatibility)

## Next steps

- Start a free account: https://portal.zuplo.com/signup
- Read the docs: https://zuplo.com/docs/mcp-gateway/code-config/overview

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