REST Services 2

NOTE (3-Sep-2025) : The KNIME Pro Hub as of now is still in Beta, so it is possible that there will be some small changes when it is released.

Here we will see how to deploy the workflow we saw on the previous page as a REST service and how to call it from applications outside of KNIME.

I connect to my KNIME hub space, search for the workflow I uploaded. In order to be able to deploy it, I first have to create a non-draft version thru the 'Versions' button , as seen below

Once I have created a new Version, I can now use the Deploy button and then select 'Service' to deploy my workflow as a REST service (see above).

Now this is done, we will see how to call the REST service outside of KNIME. But before we do this, first we have to take care of an additional step, which is to create an Application ID and Password to control access to our REST service. To do this, on your KNIME Hub space , first select 'Settings' and then 'Application Passwords and then the '+'  icon ' (see screenshots below).

When you get to this stage, copy the ID and Password values and save them. You will need them later on. Be aware that this will be your only chance to get the 'password' value. In case you lose it, you will have to create a new ID / password pair , as explained above.

Now we are ready to test calling our REST service from outside of KNIME. But first, I have to find out HOW. For this, on my KNIME Hub space, I navigate back to where I uploaded the  Airport REST lookup workflow (see higher) , scroll down to 'Deployments' and there., from the three-dot menu, select 'Open API docs' (see below)

This will bring up a page that looks like the one below.

What we will need later on is the URL part in the red box to test out our REST service.

There are several tools available to test REST services. The one I will be using here is Postman .  To use Postman, you will have to create an account, but the free tier is sufficient for our use.

Then, click the 'New Request' button (see red box below)

On the page you get now in Postman, we have to fill out some things:

• On the URL field (red box below), for the call method we select 'POST' and in the URL field we paste the value we found above  (in API docs for our REST service). Don't forget to include the https://api.hub.knime.com part !

• Below, under the 'Authorization' tab (yellow boxes below),  we select 'Basic Auth' as Auth Type and in the Username and Password fields, we enter/paste the values from the Application Passwords step above

Now, what is left to do, is supply the input parameter for our request.

In order to do this, select the 'Body' tab, select 'RAW' as input type and type in the JSON fragment below (red boxes).

Now we are all set up and can hit the SEND button to send our request (yellow box)

Now, if everything went well, we should see a '200 OK' response and the correct output value from our REST call ! (red boxes below).

We can play around and try different Airport IATA codes to test it further.

On the final page on this topic, I will show you how to create a Python program to call our REST service in a very easy way...