JSON Schema

This handler allows you to load any remote REST service, and describe it's request/response using the YAML config.

With this handler, you can easily customize and control the built GraphQL schema.

To get started, install the handler library from NPM:

$ yarn add @graphql-mesh/json-schema

Now, you can use it directly in your Mesh config file:

sources:

- name: MyApi

handler:

jsonSchema:

baseUrl: https://some-service-url/endpoint-path/

operations:

- type: Query

field: users

path: /users

method: GET

responseSchema: ./json-schemas/users.json

Dynamic Values

Mesh can take dynamic values from the GraphQL Context or the environmental variables. If you use mesh serve, GraphQL Context will be the incoming HTTP request.

The expression inside dynamic values should be as in JS.

From Context (HTTP Header for mesh serve)

sources:

- name: MyGraphQLApi

handler:

jsonSchema:

baseUrl: https://some-service-url/endpoint-path/

operationHeaders:

# Please do not use capital letters while getting the headers

Authorization: Bearer {context.headers['x-my-api-token']}

And for mesh serve, you can pass the value using x-my-graphql-api-token HTTP header.

From Environmental Variable

MY_API_TOKEN is the name of the environmental variable you have the value.

sources:

- name: MyGraphQLApi

handler:

jsonSchema:

baseUrl: https://some-service-url/endpoint-path/

operationHeaders:

Authorization: Bearer ${MY_API_TOKEN}

# You can also access to the cookies like below;

# Authorization: Bearer {context.cookies.myApiToken}

From Arguments

Mesh automatically generates arguments for operations if needed;

sources:

- name: MyGraphQLApi

handler:

jsonSchema:

baseUrl: https://some-service-url/endpoint-path/

operations:

- type: Query

field: user

path: /user/{args.id}

method: GET

responseSchema: ./json-schemas/user.json

This example operation definition will generate a root field with id: ID argument, then Mesh will interpolate the expression in path to get id value from args.

Codesandbox Example

You can check out our example that uses JSON Schema handler with mock data.

Config API Reference

• baseUrl (type: String)
• operationHeaders (type: JSON)
• schemaHeaders (type: JSON)
• operations (type: Array of Object, required):
  • field (type: String, required)
  • path (type: String)
  • pubsubTopic (type: String)
  • description (type: String)
  • type (type: String (Query | Mutation | Subscription), required)
  • method (type: String (GET | DELETE | POST | PUT | PATCH))
  • requestSchema (type: Any)
  • requestSample (type: Any)
  • requestTypeName (type: String)
  • responseSample (type: Any)
  • responseSchema (type: Any)
  • responseTypeName (type: String)
  • argTypeMap (type: JSON)
  • headers (type: JSON)
• disableTimestampScalar (type: Boolean)
• baseSchema (type: Any)
• errorMessageField (type: String) - Field name of your custom error object (default: 'message')