Apollo MCP Server Guide

Apollo MCP Server exposes GraphQL operations as MCP tools, enabling AI agents to interact with GraphQL APIs through the Model Context Protocol.

Quick Start

Step 1: Install

# Using npm
npm install -g @apollo/mcp-server

# Or run directly with npx
npx @apollo/mcp-server

Step 2: Configure

Create mcp.yaml in your project root:

# mcp.yaml
endpoint: https://api.example.com/graphql
schema:
  type: local
  path: ./schema.graphql
operations:
  type: local
  paths:
    - ./operations/**/*.graphql
introspection:
  enabled: true

Step 3: Connect

Add to your MCP client configuration:

Claude Desktop (claude_desktop_config.json):

{
  "mcpServers": {
    "graphql-api": {
      "command": "npx",
      "args": ["@apollo/mcp-server", "--config", "./mcp.yaml"]
    }
  }
}

Claude Code (.mcp.json):

{
  "mcpServers": {
    "graphql-api": {
      "command": "npx",
      "args": ["@apollo/mcp-server", "--config", "./mcp.yaml"]
    }
  }
}

Built-in Tools

Apollo MCP Server provides four introspection tools:

Defining Custom Tools

MCP tools are created from GraphQL operations. Three methods:

1. Operation Files (Recommended)

operations:
  type: local
  paths:
    - ./operations/**/*.graphql

# operations/users.graphql
query GetUser($id: ID!) {
  user(id: $id) {
    id
    name
    email
  }
}

mutation CreateUser($input: CreateUserInput!) {
  createUser(input: $input) {
    id
    name
  }
}

Each named operation becomes an MCP tool.

2. Operation Collections

operations:
  type: collection
  id: your-collection-id

Use GraphOS Studio to manage operations collaboratively.

3. Persisted Queries

operations:
  type: manifest
  path: ./persisted-query-manifest.json

For production environments with pre-approved operations.

Reference Files

Detailed documentation for specific topics:

• Tools - Introspection tools and minify notation
• Configuration - All configuration options
• Troubleshooting - Common issues and solutions

Key Rules

Security

• Never expose sensitive operations without authentication
• Use headers configuration for API keys and tokens
• Prefer introspection.enabled: false in production
• Set introspection.mutationMode: prompt to require confirmation for mutations

Authentication

# Static header
headers:
  Authorization: "Bearer ${APOLLO_API_KEY}"

# Dynamic header passthrough
headers:
  X-User-Token:
    from: x-forwarded-token

Token Optimization

Enable minification to reduce token usage:

introspection:
  minify: true

Minified output uses compact notation:

• T = type, I = input, E = enum
• s = String, i = Int, b = Boolean, f = Float
• ! = required, [] = list

Mutations

Control mutation behavior:

introspection:
  mutationMode: allowed   # Execute directly
  mutationMode: prompt    # Require confirmation (default)
  mutationMode: disabled  # Block all mutations

Common Patterns

GraphOS Cloud Schema

schema:
  type: uplink
graphos:
  key: ${APOLLO_KEY}
  graph_ref: my-graph@production

Local Development

endpoint: http://localhost:4000/graphql
schema:
  type: local
  path: ./schema.graphql
introspection:
  enabled: true
  mutationMode: allowed

Production Setup

endpoint: https://api.production.com/graphql
schema:
  type: uplink
operations:
  type: manifest
  path: ./persisted-query-manifest.json
introspection:
  enabled: false

Ground Rules

• ALWAYS configure authentication before exposing to AI agents
• ALWAYS use mutationMode: prompt in shared environments
• NEVER expose introspection tools with write access to production data
• PREFER operation files over ad-hoc execute for predictable behavior
• USE GraphOS Studio collections for team collaboration