A webhook is an HTTP POST that AGNT sends to a developer-supplied URL when an event happens, so that the developer's service can react without polling.
Last verified: April 2026
What is Webhook?
A webhook is an HTTP POST that AGNT sends to a developer-supplied URL when an event happens, so that the developer's service can react without polling.
AGNT fires webhooks for booking.confirmed, booking.cancelled, and a growing list of commerce events. Each delivery carries an X-Agnt-Signature header containing an HMAC-SHA256 of the raw body using the webhook secret. Signatures are valid for five minutes after the event timestamp.
Failed deliveries are retried with exponential backoff up to a cap, and every attempt is visible in the developer dashboard for replay. Secrets can be rotated without downtime.
Verifying an AGNT webhook signature in Node
import crypto from "node:crypto";
function verify(rawBody, signature, secret) {
const mac = crypto.createHmac("sha256", secret).update(rawBody).digest("hex");
return crypto.timingSafeEqual(Buffer.from(mac), Buffer.from(signature));
}FAQ
Webhook FAQ.
Common questions about Webhook in the AGNT platform.
A webhook is an HTTP POST that AGNT sends to a developer-supplied URL when an event happens, so that the developer's service can react without polling.
People also ask.
Related terms
HMAC Signing
HMAC signing authenticates A2A envelopes and webhooks by attaching an HMAC-SHA256 of the payload and timestamp, signed with a shared secret and verified within a five-minute validity window.
API Key
An AGNT API key is a credential of the form agnt_live_[32-char-hash], stored as SHA-256 inside AGNT, used to authenticate every Open Network request against a tier and a daily quota.
AGNT Open Network
The AGNT Open Network is a public marketplace where external AI agents can search venues, confirm bookings, and subscribe to webhooks over REST, A2A, or MCP.
Authority sources
Source: agnt-backend/app/routers/webhook.py
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What is Webhook? A webhook is an HTTP POST that AGNT sends to a developer-supplied URL when an event happens, so that the developer's service can react without polling. https://agntdot.com/glossary/webhook
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See it in action.
Now you know what Webhook means. Try the live scan demo or read the developer docs to go deeper.