This is a tool to generate API code or type annotations based on a GraphQL schema and query documents.

It currently generates Swift code, TypeScript annotations and Flow annotations, we hope to add support for other targets in the future.

See Apollo iOS for details on the mapping from GraphQL results to Swift types, as well as runtime support for executing queries and mutations.

If you want to experiment with the tool, you can install the apollo-codegen command globally:

npm install -g apollo-codegen

To download a GraphQL schema by sending an introspection query to a server:

apollo-codegen introspect-schema http://localhost:8080/graphql --output schema.json

You can use the header option to add additional HTTP headers to the request. For example, to include an authentication token, use --header "Authorization: Bearer <token>".

You can use the insecure option to ignore any SSL errors (for example if the server is running with self-signed certificate).

Note: The command for downloading an introspection query was named download-schema but it was renamed to introspect-schema in order to have a single command for introspecting local or remote schemas. The old name download-schema is still available is an alias for backward compatibility.

To generate a GraphQL schema introspection JSON from a local GraphQL schema:

apollo-codegen introspect-schema schema.graphql --output schema.json

This tool will generate Swift code by default from a set of query definitions in .graphql files:

apollo-codegen generate **/*.graphql --schema schema.json --output API.swift

You can also generate type annotations for TypeScript or Flow using the --target option:

# TypeScript
apollo-codegen generate **/*.graphql --schema schema.json --target typescript --output schema.ts
# Flow
apollo-codegen generate **/*.graphql --schema schema.json --target flow --output schema.flow.js

If the source file for generation is a javascript or typescript file, the codegen will try to extrapolate the queries inside the gql tag templates.

The tag name is configurable using the CLI --tag-name option.

Running tests locally:

npm install
npm test