Effect GQL

Why Effect GQL?

Type-Safe End-to-End

Define your schema once with Effect Schema. Get automatic TypeScript types, GraphQL types, and runtime validation.

Effect-Powered Resolvers

Resolvers are Effect programs with built-in error handling, service injection, and composability.

Service Integration

Use Effect’s Layer system for dependency injection. No magic, just types.

Functional & Immutable

Immutable builder pattern with pipe-able API. Compose your schema from reusable parts.

Quick Example

import { Effect } from "effect"
import * as S from "effect/Schema"
import { GraphQLSchemaBuilder } from "@effect-gql/core"

// Define your schema with Effect Schema
const UserSchema = S.Struct({
  id: S.String,
  name: S.String,
  email: S.String,
})

// Build your GraphQL schema
const schema = GraphQLSchemaBuilder.empty
  .objectType({ name: "User", schema: UserSchema })
  .query("user", {
    type: UserSchema,
    args: S.Struct({ id: S.String }),
    resolve: (args) => Effect.succeed({
      id: args.id,
      name: "Alice",
      email: "alice@example.com",
    }),
  })
  .buildSchema()

Features

Schema Builder

Fluent, immutable API for building GraphQL schemas with full type inference.

Automatic Validation

Arguments validated automatically using Effect Schema before resolvers run.

Subscriptions

First-class subscription support using Effect Streams.

DataLoader Integration

Built-in batching and caching with Effect-based DataLoaders.

Structured Errors

Type-safe error handling that integrates with GraphQL’s error system.

Request Context

Request-scoped context using Effect’s Layer system.