Using Aspose cloud for MS Power Platform Custom Connector

Aspose.HTML Cloud Product Family
1

Is it possible to use APOSE Cloud HTML for a custom connector in Power Automate? It has OAuth2.0 support but I’m not certain if I can get Aspose to work with it. From what I’ve read ASPOSE Cloud does not have an authorization URL and instead use the token URL for authorization. I tried to use the token URL in for the authorization URL as well and get ‘unsupported grant type’. So I wanted to see if this is even possible.

2

@tstormAPI

Can you please provide more details about the specific error message you are encountering and the steps you have taken to configure the custom connector with Aspose Cloud HTML?

3

Hi @tstormAPI
Yes, Aspose.HTML Cloud API uses OAuth 2.0 Client Credentials flow, which means you authenticate server-to-server using a client_id and client_secret to obtain a Bearer token.
Documentation: Aspose Cloud Authorization API

This flow does not include an authorizationUrl (used for user consent/login), but only a tokenUrl:

POST https://api.aspose.cloud/connect/token

Can it work with Power Automate custom connector?

Yes, but with limitations.

Power Automate’s OAuth2.0 custom connector configuration expects Authorization Code flow, which includes both:

  • authorizationUrl (user-facing login/consent screen)
  • tokenUrl (to exchange code for token)

Aspose Cloud only provides the tokenUrl and uses Client Credentials flow. That means:

  • :white_check_mark: It works for server-to-server apps
  • :x: It does not support user-based login/authorization in Power Automate

Workarounds

  1. Use manual token in header (limited, not dynamic):
    You can obtain a bearer token outside Power Automate and pass it manually using a static custom header:

    Authorization: Bearer {your_token}

    Token expires after 1 hour, so this is not sustainable for production.

  2. Use HTTP Actions in Power Automate instead of custom connector:
    Create a flow using Power Automate’s HTTP action:

    • Step 1: Call https://api.aspose.cloud/connect/token with client credentials
    • Step 2: Extract token from response
    • Step 3: Use the token in a second HTTP action to call Aspose API

  3. Create a proxy via Azure Function or API middleware:
    Set up an Azure Function or lightweight backend that:

    • Handles token generation
    • Proxies the call to Aspose API
    • Accepts simple requests from Power Automate

Summary

  • Aspose Cloud supports OAuth2 client credentials flow
  • Power Automate’s OAuth2 connector setup requires an authorizationUrl and won’t work directly
  • You can still integrate using:
    • Power Automate HTTP actions
    • Middleware or proxy functions
4

Thanks for quick response. I’ll give the HTTP Actions in power automate a try.

5

Sure, please let us know when you have more question