Designing API interface

[yasserbouat]

Hello,

I hope you all re doing great,

I m looking for a course or tutorial to learn how to design an API interface between Servicenow and an external system then implement it , so if you have any ressource please share 

Thanks,

[Tanushree Maiti]

Hi @yasserbouat 

With third party you can connect from servicenow using api in several ways like 

• Scripted Rest API
• Outbound Web Services (REST / SOAP) 
• IntegrationHub & Spokes
• Table API   etc.

Depending wheather you are looking for using low-code tools or writing custom scripts.

Check these resources: 

https://www.youtube.com/watch?v=9KvNrFdaPlI

https://www.servicenow.com/docs/r/api-reference/api-implementation-reference.html

https://www.youtube.com/watch?v=7POS69Rcs6g

https://www.youtube.com/watch?v=6IfPC5m9ZxA

https://www.youtube.com/watch?v=xtYjSjkrnBM  

[Vishal Jaswal]

Hello @yasserbouat 

Try below to begin with:

Navigate to All > System Web Services > Outbound > REST Message - Click New

Free REST API to play with: https://reqres.in/ 

Hit Submit and then open the Default GET HTTP Method:

Update the endpoint and add HTTP Headers under HTTP Request tab as shown below:

Hit Save and Under Related Links, click Test:

Now under Related Links, Click Preview Script Usage and copy the code:

Navigate to All > System Definition > Scripts - Background -  paste the code add add below as shown below

gs.print(responseBody);

Now you can start modifying the script based upon httpStatus to make it more robust as shown below:

[sanjaygupta]

ServiceNow’s own Now Learning platform is the best place to start, and it is enough to design and build both directions of an integration. Community members recommend this learning order, and the course titles below are the ones they name. Titles change over time, so search Now Learning to confirm them.

• Take Get Started with Integrations on Now Learning, where several on-demand integration courses are free.
• Continue with Web Service Integrations, then REST Integration: Create Inbound REST Requests.
• For receiving calls from the external system, take REST Integration: Create Scripted REST APIs, or the From the Experts: ServiceNow Scripted REST APIs course, where the instructor says to define your requirements as precisely as possible before developing.
• For calling the external system, practice with REST Messages and the RESTMessageV2 scripting described in the Australia documentation under Scripting outbound REST.
• Use a free Personal Developer Instance (PDI) to practice. A ServiceNow-to-ServiceNow integration is a good first exercise because it covers both inbound and outbound calls.
• Take Integration Hub: Introduction last. Community advice is to learn REST first, because Integration Hub is easier once those concepts are clear.

For the design stage, agree the data fields, authentication method (basic or OAuth 2.0), error handling and retry behavior with the external team before you build. The Australia documentation covers inbound and outbound web services under the API reference, including outbound REST authentication.

Sources:

• From the Experts: ServiceNow Scripted REST APIs
• Plan to learn integrations (Community)
• Integration course suggestions on Now Learning (Community)
• Scripting outbound REST (Australia)

[Tanushree Maiti]

Hi @sanjaygupta 

Check API references in Servicenow Documentation.

https://www.servicenow.com/docs/r/api-reference/api-reference.html

https://www.servicenow.com/docs/r/api-reference/developer-guides/developer-guides.html?contentId=qXT...