Webhooks by Zapier - Move Your Data Instantly With Webhooks
PublicAPIs - Explore the largest API directory in the galaxy
Webhook.site - Instantly generate a free, unique URL and email address to test, inspect, and automate (with a visual workflow editor and scripts) incoming HTTP requests and emails.
API List - A collective list of APIs. Build something.
Hookdeck - Hookdeck makes it simple to build and deploy reliable, testable, and debuggable applications that rely on webhooks.
Outerbridge - Connect Web3 and Web2 API without code