{"id":786,"date":"2026-10-12T14:28:40","date_gmt":"2026-10-12T04:28:40","guid":{"rendered":"https:\/\/www.cloudproinc.com.au\/?p=786"},"modified":"2026-10-12T14:28:40","modified_gmt":"2026-10-12T04:28:40","slug":"auto-generate-azure-bearer-token-with-postman","status":"publish","type":"post","link":"https:\/\/www.cloudproinc.com.au\/index.php\/2026\/10\/12\/auto-generate-azure-bearer-token-with-postman\/","title":{"rendered":"Auto-Generate Azure Bearer Token with Postman"},"content":{"rendered":"\n

In this Postman and Azure REST API, I will show you how to auto-generate a bearer token for each Azure REST API request with Postman.<\/p>\n\n\n\n\n\n\n\n

<\/path><\/svg><\/span><\/span>Estimated reading time: <\/span>3<\/span> minutes<\/span><\/p>\n\n\n\n

Postman API client allows us to develop API requests to many cloud services using an intuitive interface.<\/p>\n\n\n\n

When it comes to Azure, We can use the Azure REST API protocol to create and manage any service on Azure using API.<\/p>\n\n\n\n

In my previous post, I showed how to Create an App Registration for Microsoft Azure REST API.<\/p>\n\n\n\n

If you’re familiar with Azure REST API, one of the steps to create an API request is to generate a temporary access token. <\/p>\n\n\n\n

Creating an access token is a manual process that must be repeated every hour when the token expires. <\/p>\n\n\n\n

In this post, I will show you how to use a Pre-Request script in Postman to auto-generate an access token before sending a request. <\/p>\n\n\n\n

Auto-Generate Azure Bearer Token with Postman<\/h2>\n\n\n\n

To auto-generate an access token, I have the following configuration. In my environment, I have the following variables.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

The variable BearerToken needs to be left empty.<\/p>\n\n\n\n

I have the following JavaScript script on my collection page under the Pre-Request script. Please note that the values in the script need to match the values in the environment variables.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Copy the script below.<\/p>\n\n\n\n

const tokenExpired = !pm.environment.get(\"bearerToken\") || Date.now() > pm.environment.get(\"bearerTokenExpiresOn\") * 1000;\n\nif (tokenExpired) {\n    const tenantId = pm.environment.get(\"tenantId\");\n    const client_id = pm.environment.get(\"client_id\");\n    const client_secret = pm.environment.get(\"client_secret\");\n    const resource = pm.environment.get(\"resource\") || \"https:\/\/management.azure.com\/\";\n\n    pm.sendRequest({\n        url: `https:\/\/login.microsoftonline.com\/${tenantId}\/oauth2\/token`,\n        method: 'POST',\n        header: { 'Content-Type': 'application\/x-www-form-urlencoded' },\n        body: {\n            mode: 'urlencoded',\n            urlencoded: [\n                { key: \"grant_type\", value: \"client_credentials\" },\n                { key: \"client_id\", value: client_id },\n                { key: \"client_secret\", value: client_secret },\n                { key: \"resource\", value: resource }\n            ]\n        }\n    }, (err, res) => {\n        if (err) {\n            console.log(err);\n        } else {\n            const { expires_on, access_token } = res.json();\n            pm.environment.set(\"bearerTokenExpiresOn\", expires_on);\n            pm.environment.set(\"bearerToken\", access_token);\n        }\n    });\n}\n<\/code><\/pre>\n\n\n\n
To use the auto-generated token in a REST request, set the Auth Type as shown below.<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n