This page explains how you can alter GraphQL API requests and responses using Requestly.
Modifying GraphQL responses
In GraphQL, there is typically just one HTTP endpoint for all client interactions. And to specify which operation to execute, it is a common practice to passĀ operationName
Ā in the request payload.
For example,
POST /graphql
{
"operationName": "getUsers",
"query": `
query getUsers {
users {
id
email
}
}
`
}
To modify response of a GraphQL request, you may create aĀ Modify API ResponseĀ rule and target operationName
Ā field in the request payload.
Select Resource Type as GraphQL API
and in GraphQL Operation (Request Payload Filter)
, enter:
- Key as
operationName
- value as
getUsers
š”
Note: Key
is the JSON key in the request payload. It also supports nested path. For instance, if operation name is available at path data.operationName
instead of root, Key can be specified as data.operationName
. Incase request body starts with an array like [{ "operationName": "value", ...}]
, Key can be specified as 0.operationName
.
Ā
If your GraphQL request does not specify operationName
, you should select Resource Type as REST API
and use Dynamic (JavaScript)
mode to filter the request and override the response.
For example, in the below GraphQL request, there is no operationName
field. The operation getUsers
is instead specified in query
field.
POST /graphql
{
"query": `
query getUsers {
users {
id
email
}
}
`
}
The JavaScript code would look like:
function modifyResponse(args) {
const {url, response, requestData, responseJSON} = args;
if (requestData.query?.includes("query getUsers")) {
// return custom response from this query
console.log("Requestly: Modifying response", { query: requestData.query });
return {...responseJSON, custom: true};
}
// return original response
return response;
}
Ā
Modifying GraphQL requests
If you have a use-case to modify the GraphQL query or variables, you may create a Modify Request BodyĀ rule where the request body can be altered.
Ā
Ā