Free Webhook.site Alternative for Scripts and Agents

The translation

Each step a webhook.site user takes has a counterpart here. The webhook.site facts are from its own documentation, pricing and terms pages as read on 4 November 2026; where those pages give two different numbers, both are quoted.

Step	webhook.site	aisenseapi.com
Get a URL	Open the site, or create a token through its API	`POST /services/v1/webhook_capture` with an empty JSON body
What you get	A unique URL, an email address and a DNS name, without signing up	`capture_id`, `update_url`, `read_url`, `wait_url` and `expire_timestamp`
Send	Any HTTP method to the URL	Any HTTP method to `update_url`
What the sender gets back	The URL's default response, which you can edit	The capture itself, as JSON
Read	The web page, or the requests route of its API	`GET read_url`: one JSON document with method, path, headers, client address and body
Wait for arrival	Watch the page update	`GET wait_url`, 0 to 25 seconds per call; returns early with `waited_seconds` and `wait_reason`
Be told	Custom Actions, with a subscription	`notify_url` at creation: one signal after the first request
Requests kept per URL	Up to a cap on a free URL; its pages give 50 in one place and 100 in another	One. The first request wins, and retries return it
Body size	Under 10 MB	256 KB
Lifetime	7 days for a free URL	24 hours
Email and DNS capture	Yes	No
Account or key	None for a free URL; API keys belong to accounts	None
Who can read it	Anyone who knows the URL's id, on a free URL	Anyone who knows the capture id

The create call looks like this, and the three URLs in its answer are all you need:

curl -X POST https://aisenseapi.com/services/v1/webhook_capture \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "ok": true,
  "capture_id": "6f8c9e52-3f2c-4e73-9d3b-8d6c3f6d1c91",
  "status": "pending",
  "update_url": "https://aisenseapi.com/services/v1/webhook_capture/6f8c9e52-.../update",
  "read_url": "https://aisenseapi.com/services/v1/webhook_capture/6f8c9e52-...",
  "wait_url": "https://aisenseapi.com/services/v1/webhook_capture/6f8c9e52-.../wait/25",
  "expire_timestamp": 1772893200
}

What differs

One request per capture. webhook.site keeps a list of requests behind one URL. A capture here holds the first request that reaches its update URL and nothing after it: it is the proof of one delivery, not an inbox. A test that expects three deliveries creates three captures. For a stream of requests you want to browse, webhook.site is the better tool.
No page to look at. Every answer is JSON, written to be read by code. The same capture is also available to AI agents as the create_webhook_capture and read_webhook_capture tools of the free MCP server, so an agent can receive a callback without writing a client.
Built to be awaited. wait_url holds the connection for up to 25 seconds and returns the moment the request lands, and notify_url sends one signal to a URL you name, which must use a host name rather than an IP address. webhook.site answers the same need with Custom Actions on a subscription.
Shorter and smaller. A capture lives 24 hours from creation, against 7 days for a free webhook.site URL, and takes a body of at most 256 KB, against 10 MB. Both are enough for a webhook payload; neither is file transfer.
The same openness. On both services a free capture is readable by whoever knows its id, which is a long random identifier in both cases. Send test secrets only. The sender's address, every header and the complete body are stored as they arrived.

A script that waits for the callback

Create the capture, hand the update URL to the sender, then wait. One call to wait_url costs one request and returns after at most 25 seconds, so a loop that waits all day spends about 3,500 of the 5,000 requests an address has per day. For anything longer than a few minutes, give notify_url instead and let the signal come to you.

import requests

BASE = "https://aisenseapi.com/services/v1/webhook_capture"

created = requests.post(BASE, json={}, timeout=10).json()
print("Give the sender:", created["update_url"])

while True:
    answer = requests.get(created["wait_url"], timeout=35).json()
    if "request" in answer:
        break

request = answer["request"]
print(request["method"], request["uri"])
print(request["headers"])
print(request["body"])          # one of json, text or base64 is filled, with raw_length

The same three steps in curl, for a shell test:

curl -s -X POST https://aisenseapi.com/services/v1/webhook_capture -H "Content-Type: application/json" -d '{}'
# point the sender at update_url, then:
curl -s "https://aisenseapi.com/services/v1/webhook_capture/{capture_id}/wait/25"

The update call answers the sender with the capture itself, so a sender that logs its responses shows you the same document.

What a capture records

Field	Type	Meaning
captured_at_timestamp	integer	Unix time of the first request.
captured_at_datetime	string	The same moment in ISO 8601, UTC.
request.method	string	The HTTP method the sender used.
request.uri	string	The path the sender actually requested, query string included.
request.headers	object	Every header received, with lower-case names.
request.client_ip	string	The sender's address as the service saw it.
request.body	object	`json`, `text` or `base64`, exactly one of them filled, and `raw_length` in bytes. A request with no body is still a capture, with all three null and a length of 0.

Errors

Case	Status	What it means
Unknown capture id	404	No capture has that id.
Capture older than 24 hours	410	The capture has expired and its data is gone.
`notify_url` with an IP address as host	400	The signal URL must use a host name.
The day's requests used up	429	The shared limit of 5,000 requests per address per day; wait for the reset.

Every refusal is JSON with error and fix.

Privacy and limits

A capture stores the sender's address, every header and the complete body, so provider signatures and Authorization headers end up stored beside the payload for 24 hours, readable by anyone who holds the capture id. Use it with test credentials, and see our privacy policy for log retention.

Every path shares the service-wide ceiling of 5,000 requests per IP address per day. A full round costs three: the create call, the inbound request and your read. A capture takes one request of at most 256 KB and lives 24 hours from creation. webhook.site, for comparison, states that a free URL and its data are removed after 7 days, that a free URL stops accepting requests at its cap, and that its paid plans start at 9 dollars a month; those are its figures as of November 2026 and may change.

Free Webhook.site Alternative