Custom connector is an extension capability of Logic Apps platform that allows you to build connectors for services or applications for which out of box connectors are not available. This feature is particularly useful for connecting to your in-house services in the same way as other connectors.
Logic Apps Standard provides multiple ways to integrate with your custom APIs or backend services. The goal of this document is to explain these options and provide recommendations. Depending on where your service is hosted, different approaches would be recommended.
Services hosted publicly on the web
If you are an ISE customer with a custom connector for services or APIs that are hosted publicly, you should be able to use the same custom connector from Logic Apps Standard. (*NEW*) We recently released the support to use Azure of managed custom connectors in Logic Apps Standard. This article covers more details.
Apart from this, you can also consider using HTTP connector or APIM connector which also provide similar capabilities
Services hosted on premises or in VNET
When a service is hosted in a VNET, there are certain pre-requisites particularly on how the network configuration is setup. We have covered those Prerequisites here. If you already have a Logic App and your service configured in the VNET, you can skip the Prerequisites.
To connect to your services or APIs hosted in a VNET, here are few options:
- APIM connector – (*NEW*) APIM connector is a great option if you are already using it in your applications. VNET support is only available in Premium SKU though.
- HTTP connector – HTTP connector is a great option if your custom connector is used from a fewer applications. It takes away the overhead of managing an additional component like APIM if you already do not have one.
- Codeful connector – This is a great option if you want your custom connector to run side by side Logic Apps runtime. This option would be recommended if you are building a more complex connector with lot of custom business logic and have high performance and low latency requirements.
Recommendations
If you are connecting to services/APIs hosted publicly, Logic Apps custom connector would be recommended. Please note that these do have limits on number of calls/minute as well as are charged based on usage (number of calls)
If you are already using APIM premium and also want to share your services/APIs across multiple Logic Apps, then APIM would be a good option.
If you do not use APIM, HTTP would be a great option. It’s a built in connector and therefore the requests go directly to the endpoint without any additional hops. There are no extra cost as well other than the compute. You do not need to manage any additional component with this option.
Note: The export tool defaults to HTTP option i.e it converts the Custom connector to HTTP connector.
For any questions or issues, please open an issue at Github and tag me (@divyaswarnkar) to it, and give a reference of this article.
