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Dynamically setting environment variables based on response JSON

You can set environment variables based on the response JSON of a HTTP request.

Create a file with the .http extension and write your HTTP requests in it.

With built-in parser​

If the response is a uncomplicated JSON object, you can set environment variables using the request variables feature.

with-builtin-parser.http
# Setting the environment variables to be used in the next request.
# @name REQUEST_ONE
POST https://httpbin.org/post HTTP/1.1
Content-Type: application/json
Accept: application/json

{
  "username": "{{USERNAME}}",
  "password": "{{PASSWORD}}",
  "token": "foobar"
}

###

POST https://httpbin.org/post HTTP/1.1
Content-Type: application/json
Accept: application/json
Authorization: Bearer {{REQUEST_ONE.response.body.$.json.token}}

{
  "success": true,
  "username": "{{REQUEST_ONE.response.body.$.json.username}}"
}

With external command​

If the response is a complex JSON object, you can use the @env-stdin-cmd directive to set environment variables using an external command (e.g., jq).

JSON Web Tokens (JWT) are a common example where the response JSON is complex.

In this example jq is used to extract the ctx string from a JWT token.

with-external-jq.http
# Setting the environment variables to be used in the next request.
# Any external command can be used to set the environment variables.
# The command should output the environment variable as string.
# @env-stdin-cmd JWT_CONTEXT jq -r '.json.token | gsub("-";"+") | gsub("_";"/") | split(".") | .[1] | @base64d | fromjson | .ctx'
POST https://httpbin.org/post HTTP/1.1
Content-Type: application/json
Accept: application/json

{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ0eXBlIjoiZ29yaWxsYSIsIm5hbWUiOiJHb3JpbGxhIE1vZSIsImN0eCI6IlNvbWUgY29udGV4dCIsIndlYnNpdGUiOiJodHRwczovL2dvcmlsbGEubW9lIn0.YmEG9bOo1o9opeWnCsfW621A-sB_5WXSBI2FjtvwXlk"
}

###

POST https://httpbin.org/post HTTP/1.1
Content-Type: application/json
Accept: application/json

{
  "success": true,
  "context": "{{JWT_CONTEXT}}"
}