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One of the 10 Most Promising Payment Solution Providers for 2022

June 5, 2022 – CIO Review

Whistle: 2022 Start-up to Watch

June 1, 2022 – St. Louis Magazine

  • Request an API key

  • Review API docs

  • Test your calls

  • Fund a budget

  • Send payments!

Whistle will be your app’s simplest integration.

The Whistle API is simple and straightforward. By not overcomplicating things we allow you to get up in running in as little as a day. Most of our partners find they can integrate payments into their flow with as little as 2 or 3 API calls. Check out the docs and try it today!