Azure Function (.NET 8 Isolated): HTTP request body is empty only when using AuthorizationLevel.Function

Question

I am calling an Azure Function HTTP trigger from Dell Boomi.

Environment:

• Azure Functions v4
• .NET 8 isolated worker
• HTTP trigger
• Caller: Dell Boomi HTTP Client
• Method: POST
• Content-Type: application/json

The function works correctly when called from Postman. The JSON request body is received and processed successfully.

However, when the same endpoint is called from Boomi with AuthorizationLevel.Function, the function receives an empty body. In the Azure Function logs I can see:

Content-Type: application/json

Content-Length: 0

User-Agent: Boomi Http Transport

x-functions-key: <function key>

Routing-Key: <value>

Request body length: 0

The request reaches the function and the function key seems to be accepted, because the function is executed. But the body is empty.

When I change the trigger to AuthorizationLevel.Anonymous and remove the x-functions-key header from Boomi, the body is received correctly.

What I tested:

• Postman with AuthorizationLevel.Function works.
• Boomi with AuthorizationLevel.Function and x-functions-key reaches the function, but Content-Length is 0.
• Boomi with AuthorizationLevel.Anonymous and no x-functions-key works.
• Request Profile Type in Boomi was changed to None.
• Content-Type is application/json.
• The Boomi process shows that the JSON document exists before the HTTP Client step.

Question:

Why does the request body become empty only when Boomi calls the Azure Function using AuthorizationLevel.Function / x-functions-key? Is there any known issue or required configuration for Boomi HTTP Client and Azure Functions function-key authentication?

Answer 1

Hi,

Are you using Parameters tab in the HTTP Client Connector setup? Please review below two articles and reply back if they apply to your issue or not:

HTTP Client Connector setting Content-Length to 0

https://community.boomi.com/s/article/HTTP-Client-Connector-setting-Content-Length-to-0

HTTP Client PUT Operation not sending JSON body

https://community.boomi.com/s/question/0D51W00007nNgCISA0/http-client-put-operation-not-sending-json-body

If the above doesn't explain/resolve the issue I would recommend testing and capturing the traffic so that you can see if Boomi is actually sending the correct info or not. One idea would be to temporarily set up a VM to serve as a stand-in for the function and send unencrypted HTTP request from Boomi while capturing traffic.

Thanks.

-TP

Answer 2

Hi Guilian Nkamga,

Welcome to Microsoft Q&A Platform.

Thank you for the detailed description and the troubleshooting steps you've already performed. This helps a lot in narrowing down the issue.

The issue is likely related to how Dell Boomi constructs the HTTP request when the x-functions-key header is present. Since Postman works with the same setup, and Boomi works when the function is anonymous, this points to a difference in how Boomi handles the request when authentication is required.

Key Observations

• Content-Length is 0 in the failing case, meaning Boomi is not sending the body at all.
• The Azure Function is triggered (authentication works), but the body is missing.

Possible Causes

1. Boomi HTTP Client Behavior: Some HTTP clients (including certain integrations and middleware) may alter their request construction when additional headers (like x-functions-key) are present, especially if the request profile or payload settings are not configured correctly.
2. Request Profile/Content-Type: Even though you set Content-Type: application/json, Boomi may require explicit configuration to send the body when custom headers are present.
3. Payload Handling: If Boomi's HTTP Client step is set to "None" or not properly mapped, it may omit the body when additional headers are added.

Please check the below configuration:

Review Boomi HTTP Client Configuration

• Double-check the Request Profile in Boomi. Ensure it's set to send the payload as JSON, not "None".
• Make sure the payload mapping is correct and the body is not being dropped when headers are added.

Test with Minimal Headers

• Try sending the request with only the required headers (Content-Type, x-functions-key) and see if the body is sent.
• Gradually add other headers to identify if a specific header is causing the issue.

Use Boomi's Raw HTTP Logging

• Enable detailed logging in Boomi to inspect the actual HTTP request being sent (headers and body). This will help confirm if the body is present before it leaves Boomi.

Check for Known Issues

• Review Dell Boomi documentation and community forums for any known issues with sending bodies alongside custom headers.

As a workaround : If possible, try sending the function key as a query parameter (?code=<function-key>) instead of a header. Azure Functions support both methods for function-level authorization.

References

• Azure Functions HTTP triggers and bindings
• Dell Boomi HTTP Client Connector Guide

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