Postman – Save a response value into a variable

This article explains how to parse a value from an API response in Postman and save it into a global variable or environment variable. This is useful when we need to use a value obtained from one request in other requests; for example, when we obtain an access token that needs to be included as the authorization header in other requests.

To keep the examples simple, I used REQ|RES (a mock REST API) for my requests and responses.

Parse response value into a global variable

Global variables are available across all Postman environments.

In this example, we want to save a token returned by a login request.

postman-login-request - sending a request to the auth endpoint to get the auth token

To parse the value of the “token” field into a global variable called “oauth_token”, click on the Tests tab and add the following JavaScript code:

const jsonResponse = pm.response.json(); pm.globals.set("oauth_token", jsonResponse.token);
Code language: JavaScript (javascript)
postman-login-request-tests-tab - saving the token from the response into the oauth_token global variable

The next time you execute the request, the token is saved into the “oauth_token” global variable.

To access the variable value, enter {{oauth_token}}. For example, in the following request we use the “oauth_token” variable in the authorization header.

postman-user-request-headers - using the oauth_token global variable that was saved from the response

Parse response value into an environment variable

Environment variables are only available in the environment you specify. Parsing a value into an environment variable is very similar to parsing a value into a global variable, which we explained above.

To parse the value of the “token” field into an environment variable called “oauth_token”, in the currently selected environment, click on the Tests tab and add the following JavaScript code:

const jsonResponse = pm.response.json(); pm.environment.set("oauth_token", jsonResponse.token);
Code language: JavaScript (javascript)
postman-env-variable-tests-tab - saving the token from the response into the oauth_token environment variable

Note: If you use the same name for an environment variable and a global variable, the environment variable takes precedence.

The next time you execute the request, the token is saved into a variable called “oauth_token” in the environment you have selected (“Development” in our case).

To see an environment variables and their values, click on the eye icon next to the environment name.

postman-dev-environment-variables

To access the variable value, enter {{oauth_token}}. For example, in the following request we use the “oauth_token” variable in the authorization header. You must select the correct environment (“Development” in our case) in order to access the variable value.

Postman - setting the Authorization header to the oauth_token environment variable

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