Power Platform Community Forum Thread Details

Hi everyone,

I'm building a flow that receives a webhook trigger ("When a HTTP request is received") and then makes a GET request to an external API using the HTTP action.

The API requires a token-based authentication header:

Authorization: Token <my_api_key>

When I call the same endpoint from the command line with curl, it works perfectly:

curl -H "Authorization: Token myapikey123" \
"https://external.api/api/v1/my_scan_id/"

Returns 200 OK with valid JSON

However, when the HTTP action in Power Automate makes the same request, the API returns:

{"detail": "Authentication credentials were not provided."}

What I've already tried:

1. Setting `Authorization: Token <key>` directly in the HTTP action Headers section — 401
2. Using the Authentication section set to "Raw" with value `Token <key>` — 401
3. Using `@{concat('Token ', 'myapikey')}` expression in the header value — 401
4. Initializing a variable with the full header value and referencing it with `@{variables('PP_Auth')}` — 401
5. Using Authentication type "API Key" with parameter location "Header" — 401

In all cases, the run history shows the Authorization header as sanitized, so I can't verify what Power Automate is actually sending.

My setup:
- Trigger: "When a HTTP request is received"
- HTTP action: GET to https://external.api/api/v1/my_scan_id/
- The API uses `Token <key>` format (not Bearer)
- The same token works perfectly from curl and from a Python script

Questions:
1. Is Power Automate modifying or stripping the Authorization header value when using a non-standard scheme like Token (instead of Bearer)?
2. Is there a reliable way to force the HTTP action to send a custom Authorization header exactly as specified?
3. Has anyone successfully used token-based auth (not Bearer/Basic/OAuth) with the HTTP connector?

Any help is appreciated. Thanks!

Categories:

Power Automate Desktop

Building flows

General topics

Hi @AS-10032226-0,

1. Is Power Automate modifying or stripping the Authorization header value when using a non-standard scheme like Token (instead of Bearer)?
No, run history masks it. It doesn’t remove it. The masking is by design.

https://community.powerplatform.com/forums/thread/details/?threadid=17d84232-43eb-4edd-a6fe-e3850309ab66

2. Is there a reliable way to force the HTTP action to send a custom Authorization header exactly as specified?
Use a Custom Connector: either API Key → Authorization (Header) and input Token …, or No auth + Set HTTP header policy to override the header precisely.
https://community.powerplatform.com/forums/thread/details/?threadid=e851e4fe-d941-4d5b-9a42-a0005c1e7a8e

https://www.serverlessnotes.com/docs/setting-headers-using-custom-connector-template-policies

3. Has anyone successfully used token-based auth (not Bearer/Basic/OAuth) with the HTTP connector?
Yes, people use API‑Key/Basic/Bearer variants by mapping/overriding Authorization via API Key model or policy; the same approach applies to Token.

https://stackoverflow.com/questions/72652226/power-automate-custom-connector-authorization-header

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