How to run one request from another using Pre-request Script in Postman

Solution 1:

As mentioned by KBusc and inspired from those examples you can achieve your goal by setting a pre-request script like the following:

pm.sendRequest({
    url: pm.environment.get("token_url"),
    method: 'GET',
    header: {
        'Authorization': 'Basic xxxxxxxxxx==',
    }
}, function (err, res) {
    pm.environment.set("access_token", res.json().token);
});

Then you just reference {{access_token}} as any other environment variable.

Solution 2:

A little late but for others who come across this post, it IS now possible to send another request from the Pre-request Script section. A few examples can be found here : https://gist.github.com/madebysid/b57985b0649d3407a7aa9de1bd327990