GraphQL Playground

Prism ships with a built-in GraphQL playground — an interactive browser UI where you can write queries, explore your schema, and test mutations in real time.

Quick Setup

Define your schema

Create your PrismGraphQLSchema with query and mutation types.

Add the middleware

Mount PrismGraphQLMiddleware on your server.

Add the playground

Mount PrismGraphQLPlayground for the interactive UI.

Open in browser

Navigate to http://localhost:8080/graphql/playground.

Complete Setup

let server = PrismHTTPServer(port: 8080)

// Your schema
let schema = PrismGraphQLSchema(query: queryType, mutation: mutationType)

// Mount GraphQL endpoint at /graphql
let graphqlMiddleware = PrismGraphQLMiddleware(schema: schema, path: "/graphql")
await server.use(graphqlMiddleware)

// Mount playground UI at /graphql/playground
let playground = PrismGraphQLPlayground(
    path: "/graphql/playground",
    graphqlEndpoint: "/graphql"
)
await server.use(playground)

try await server.start()

Now visit http://localhost:8080/graphql/playground to start exploring.

How It Works

The playground provides:

Query editor with syntax highlighting
Variables panel for parameterized queries
Response viewer with formatted JSON
Keyboard shortcut — Cmd+Enter (or Ctrl+Enter) to execute

The playground is a self-contained HTML page embedded in the binary — no external CDN or network requests needed. It works completely offline.

Passing Context

Pass application context (like a database connection) to your resolvers via the middleware:

Context Setup

let db = try PrismDatabase(path: "app.db")

let graphqlMiddleware = PrismGraphQLMiddleware(
    schema: schema,
    path: "/graphql",
    context: db  // Available as info.context in resolvers
)

API Endpoints

The middleware handles both GET and POST requests:

POST (recommended)
GET

curl -X POST http://localhost:8080/graphql \
  -H "Content-Type: application/json" \
  -d '{"query": "{ hello }", "variables": {}}'

curl "http://localhost:8080/graphql?query=%7B%20hello%20%7D"

Introspection

The playground uses introspection to discover your schema. Try this query to see all available types:

Schema Introspection

{
  __schema {
    queryType {
      name
    }
    mutationType {
      name
    }
    types {
      name
      fields {
        name
        type {
          name
        }
      }
    }
  }
}

Production Considerations

The GraphQL playground should typically be disabled in production to prevent unauthorized schema exploration. Consider mounting it conditionally:

Conditional Playground

let config = PrismConfig.load()

await server.use(graphqlMiddleware)

if config.isDevelopment {
    await server.use(PrismGraphQLPlayground())
}

Core

Middleware

Database

Real-Time

Content

Server Security

GraphQL

MCP

Infrastructure

Advanced

Testing

Playground

GraphQL Playground

Quick Setup

How It Works

Passing Context

API Endpoints

Introspection

Production Considerations

What’s Next

Schema

MCP Server

​GraphQL Playground

​Quick Setup

​How It Works

​Passing Context

​API Endpoints

​Introspection

​Production Considerations

​What’s Next

Schema

MCP Server

GraphQL Playground

Quick Setup

How It Works

Passing Context

API Endpoints

Introspection

Production Considerations

What’s Next