Query Anything

GraphQL Mesh can consume different data source types inside GraphQL while composing your unified graph.

The example below loads a GraphQL subgraph. You can see available source handlers on the menu.

mesh-config.ts

import { defineConfig, loadGraphQLHTTPSubgraph } from '@graphql-mesh/compose-cli'
 
export const composeConfig = defineConfig({
  subgraphs: [
    {
      sourceHandler: loadGraphQLHTTPSubgraph('Users', {
        endpoint: 'http://localhost:4001/users'
      })
    }
  ]
})

Setting Headers

⚠️

This method is not relevant to all handlers!

Please make sure the handler you are using supports this method: You can do it by checking if handler’s config reference (appearing on it’s designated doc) includes the header fields mentioned in this doc.

Setting configurations

There are two headers-designated configuration fields under each handler - schemaHeaders and operationHeaders:

`operationHeaders`

Optional field. Used to set the Headers for operation execution. Expects JSON object representing the Headers.

In this example operationHeaders is used to defined the content of the request as Json:

mesh-config.ts

import { defineConfig, loadGraphQLHTTPSubgraph } from '@graphql-mesh/compose-cli'
 
export const composeConfig = defineConfig({
  subgraphs: [
    {
      sourceHandler: loadGraphQLHTTPSubgraph('Users', {
        endpoint: 'http://localhost:4001/users',
 
        operationHeaders: {
          'Content-Type': 'application/json'
        }
      })
    }
  ]
})

`schemaHeaders`

Optional field. Used to set the Headers for schema introspection. Expects JSON object representing the Headers.

Dynamic Header Values (e.g., for Authorization)

Mesh can take dynamic values from the GraphQL Context or the environmental variables.

The expression inside dynamic values should be as in JS.

From Context

mesh-config.ts

import { defineConfig, loadGraphQLHTTPSubgraph } from '@graphql-mesh/compose-cli'
 
export const composeConfig = defineConfig({
  subgraphs: [
    {
      sourceHandler: loadGraphQLHTTPSubgraph('Users', {
        endpoint: 'http://localhost:4001/users',
 
        operationHeaders: {
          // Please do not use capital letters while getting the headers
          // Use "{context.headers['x-my-api-token']}" if you want just the value of the header
          Authorization: 'Bearer {context.headers["x-my-api-token"]}'
          // You can also access to the cookies like below;
          // Authorization: Bearer {context.cookies.myApiToken}
        }
      })
    }
  ]
})

From Environment Variables

Set up the variable on your environment, e.g VERY_SECRET_TOKEN=12345. Then you can use it using {env.VERY_SECRET_TOKEN}.

The config wil look something like:

mesh-config.ts

import { defineConfig, loadGraphQLHTTPSubgraph } from '@graphql-mesh/compose-cli'
 
export const composeConfig = defineConfig({
  subgraphs: [
    {
      sourceHandler: loadGraphQLHTTPSubgraph('Users', {
        // You can also use the environment variables in the endpoint
        endpoint: 'http://{env.MY_HOST_NAME}:4001/users',
 
        operationHeaders: {
          Authorization: 'Bearer {env.VERY_SECRET_TOKEN}'
        }
      })
    }
  ]
})

Getting Started GraphQL