Postman Flows: 1 Flow To Smoke Test Your API Estate

One of the things that I love most about airing a new talk is the new ideas it sparks. On Friday, I delivered my talk “Go with the Flow” for the first time, to the lovely internal community at Dunelm.

LinkedIn Post from Dunelm, who were the first to give feedback on my new talk around Postman Flows

The inspiration for this post goes to Adam Pike of Dunelm, who during the talk mused that Flows would make it possible to see the full suite of APIs interacting with each other in Postman.

And it got me thinking. We know Flows has this superpower of being able to call any other collections in a workspace. If you have different collections for all your different APIs, wouldn’t it be handy to be able to visually see the key connections and check they’re all talking to each other?

Here’s a couple of ways I think it could work.

Simple Ping Smoke Test

Example smoke test Flow showing several requests being checked and errors logged out to Slack

In this example, I’m using 3 requests which can belong to different API’s. I’m then checking for the status indicator – however, you can just as easily check for status code != 200 or in a range of allowed values or similar. This then outputs to the console log if all is well, or, if there is a problem, a Slack message is output to the team with the Flows ID to alert them to an issue.

Advanced Integration Smoke Test

But what if what you want to keep an eye on is whether API’s are working when strung together in a real-world customer journey? Will the Auth API talk to the Orders API? Will the Location API talk to the 3rd party Google API? Perhaps you have mocks for third party services, but want to check if they return their end of the bargain and give you what you expect, that your internal API’s will respond in the right way?

Flows can allow you to create that visual map of your API estate.

I see it developing like a spiderweb, with a start button in the middle branching off into different workflows, all executing at the same time. 🕸️

Here’s a very rough idea of what that could look like:-

Flow containing 2 integration tests running concurrently

The Yellow Flow shows API 1, authenticating, posting and deleting. The Blue flow shows a different API flow entirely – you can of course use multiple APIs in a single flow if you wish. Using the colour feature we can code each flow to make it easy to see if they are running as expected, tagging a different API in a different colour (maybe mocked APIs in grey, for example). If not, we evaluate the status code and if we don’t like what comes back, we send a message to Slack.

Once you are confident you aren’t generating heaps of information that will just be ignored, and no false negatives(remember to test the tests!), you might even want to get this up on a monitor and schedule a run for every 5 minutes or so, just to give you the confidence everything is up and running in the environments you need things to work in.

Thanks again to Adam for the inspiration – I think this might be a useful feature to have.

Hope this helps, til next time!


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