1. graphql-ppx

We rely on Graphql-ppx for typesafe GraphQL operations and fragments in ReasonML. Go to the official documentation for installation instructions.

You should now have a graphql_schema.json in your project somewhere. Make sure it's always up-to-date!

2. Apollo Client

npm install rescript-apollo-client @apollo/client

3. Apollo-Specific graphql-ppx Configuration

Add the following under bs-dependencies and graphql, in your bsconfig.json

"graphql": {
+ "apolloMode": true,
+ "extendMutation": "ApolloClient.GraphQL_PPX.ExtendMutation",
+ "extendQuery": "ApolloClient.GraphQL_PPX.ExtendQuery",
+ "extendSubscription": "ApolloClient.GraphQL_PPX.ExtendSubscription",
+ "templateTagReturnType": "ApolloClient.GraphQL_PPX.templateTagReturnType",
+ "templateTagImport": "gql",
+ "templateTagLocation": "@apollo/client"
"ppx-flags": ["@reasonml-community/graphql-ppx/ppx"],
"bs-dependencies: [
+ "rescript-apollo-client"
  • "apolloMode" automaticaly sprinkles __typename throughout our operation and fragment definitions
  • "templateTag*" is how we tell graphql-ppx to wrap every operation with gql
  • "extend*" allows rescript-apollo-client to automatically decorate the generated modules with Apollo-specific things like the correct hook for that operation!

If you use a bundler that does not support require statements (eg: esbuild), you will need to add one more piece of configuration

"graphql": {
+ "templateTagIsFunction": true,
This is probably temporary, until ReScript supports template tags or has some way to output them.
See [this graphql-ppx issue](