Webhook
An automatic notification one application sends to another’s web address when something happens, such as “the transcript is ready”.
A webhook is an HTTP request an application sends on its own to an address you give it, as soon as an event happens. It’s the opposite of asking an API every few minutes (“is it ready yet?”): with a webhook, you get told.
Example: when a meeting’s transcript is ready, the application sends that meeting’s data to your server. Your system can then save it to your intranet, create a record in your CRM or start another process.
Since anyone could send requests to that address, proper webhooks are signed: your server checks the signature with a secret key before trusting the content.
Echo sends a webhook when a file finishes or fails, with the X-Echo-Signature header (HMAC-SHA256 with a key shown once) and retries if your server doesn’t respond. There’s also a public API for uploading and reading files. More on the API and MCP page.
