How much does a url-unshorten call cost?

$0.002 per call, paid in USDC on Base via x402, with no account and no API key.

What does url-unshorten return?

A JSON object with 15 top-level fields: requested_url, source_url, final_url, final_status, final_host, final_content_type, hop_count, reached_final, stopped_reason, cross_host, hops, initial_host_is_known_shortener, shortener_list_version, checked_at and fetched_at. The example on this page is a real call over web/unshorten-start.html and web/unshorten-landing.html.

What happens when a url-unshorten call fails?

The tool answers with a typed JSON error from the errors table. Payment is settled only after the tool has produced its result; a call that fails inside the tool is never settled. A 503 upstream_unavailable can follow a settled call; the x402 payments guide covers it, 429, 402 and an uncertain 500.

catalogue / tools / Fetch & extract / URL Unshorten API

URL Unshorten API

Follows a shortened or tracking URL to its real destination and returns every hop it went through.

Endpoint: POST /v1/url-unshorten
Price: $0.002 per call
Family: Fetch & extract
Docs: /docs/url-unshorten

01When to use it

Resolving a short link needs the network, and doing it safely needs a hardened client: an agent that follows the redirects itself will happily walk into a private address or a redirect loop.

When not to use it

The destination needs more than 10 s to answer: the call ends with upstream_timeout (424).
The destination is on a private or local network: the network guard refuses it with blocked_target (403).

02Parameters

Field	Type	Required	Description
url	string	yes	The short or tracking URL to follow, up to 2048 characters; every hop, the first included, goes through the SSRF guard.
max_hops	integer	no	Most redirects to follow, 1 to 10, default 10; a chain that has not ended by then fails as unprocessable, and a meta refresh at the limit stops with stopped_reason hop_limit. Default: 10.
method	string	no	auto sends HEAD and retries the same hop with GET on a 400, 403, 405 or 501; head and get force one method for every hop. One of: "auto", "head", "get". Default: "auto".
follow_meta_refresh	boolean	no	Whether to also follow an HTML meta refresh with a delay of 30 seconds or less, found in the first 64 KiB of a 2xx HTML or untyped page; method head turns it off, and JavaScript redirects are never followed. Default: false.

03Limits

Limit	Value
Size cap	64 KB (65,536 bytes)
Timeout	10 s

04Example

The published example of url-unshorten, verbatim: the request body and the response it returns.

Request

POST /v1/url-unshorten
content-type: application/json
payment-signature: <base64 x402 payload>

{
  "url": "https://grist.tools/samples/web/unshorten-start.html",
  "max_hops": 10,
  "follow_meta_refresh": true
}

Response

200 OK
payment-response: <base64 settlement receipt>

{
  "requested_url": "https://grist.tools/samples/web/unshorten-start.html",
  "source_url": "https://grist.tools/samples/web/unshorten-start.html",
  "final_url": "https://grist.tools/samples/web/unshorten-landing.html",
  "final_status": 200,
  "final_host": "grist.tools",
  "final_content_type": "text/html; charset=utf-8",
  "hop_count": 1,
  "reached_final": true,
  "stopped_reason": null,
  "cross_host": false,
  "hops": [
    {
      "url": "https://grist.tools/samples/web/unshorten-start.html",
      "method": "GET",
      "status": 200,
      "location": "unshorten-landing.html",
      "resolved_location": "https://grist.tools/samples/web/unshorten-landing.html",
      "kind": "meta_refresh",
      "host": "grist.tools"
    },
    {
      "url": "https://grist.tools/samples/web/unshorten-landing.html",
      "method": "GET",
      "status": 200,
      "location": null,
      "resolved_location": null,
      "kind": "final",
      "host": "grist.tools"
    }
  ],
  "initial_host_is_known_shortener": false,
  "shortener_list_version": "2026-08-26",
  "checked_at": "2026-09-01T12:00:00.000Z",
  "fetched_at": "2026-09-01T12:00:00.000Z"
}

Sample file: web/unshorten-start.html. Tiny HTML page whose only job is a zero-delay meta refresh to unshorten-landing.html, standing in for a short link served as a static file. Sample file: web/unshorten-landing.html. Tiny HTML landing page with a heading and one sentence and no redirect, the end of the unshorten-start.html chain.

In web/unshorten-start.html, the document declares language en and the title "Moved"; the body holds 1 a and 1 p elements; no script element; its one link points to unshorten-landing.html. Across the whole file, the markup opens 8 tags, 3 of them inside the head. In web/unshorten-landing.html, the document declares language en and the title "Landing page"; the body holds 1 h1 and 1 p elements; no script element; its heading reads "Landing page". Across the whole file, the markup opens 7 tags, 2 of them inside the head.

Response field	Type	In the example
requested_url	string	"https://grist.tools/samples/web/unshorten-start.html"
source_url	string	"https://grist.tools/samples/web/unshorten-start.html"
final_url	string	"https://grist.tools/samples/web/unshorten-landing.html"
final_status	number	200
final_host	string	"grist.tools"
final_content_type	string	"text/html; charset=utf-8"
hop_count	number	1
reached_final	boolean	true
stopped_reason	null	null
cross_host	boolean	false
hops	array	2 items, each with url, method, status, location, resolved_location, kind and host
initial_host_is_known_shortener	boolean	false
shortener_list_version	string	"2026-08-26"
checked_at	string	"2026-09-01T12:00:00.000Z"
fetched_at	string	"2026-09-01T12:00:00.000Z"

05Call it from code

JavaScript

// url-unshorten: $0.002 per call, paid in USD Coin on eip155:8453 via x402
// Install: npm install @x402/fetch@2 @x402/evm@2 viem@2
// Save as client.mjs (ES module, Node 18+), export EVM_PRIVATE_KEY with the paying wallet's key in your shell, then run: node client.mjs
// The wrapper reads the 402 (payment-required), signs and retries with payment-signature.
import { wrapFetchWithPayment, x402Client, decodePaymentResponseHeader } from '@x402/fetch'
import { ExactEvmScheme } from '@x402/evm/exact/client'
import { privateKeyToAccount } from 'viem/accounts'

const account = privateKeyToAccount(process.env.EVM_PRIVATE_KEY)
const client = new x402Client().register('eip155:8453', new ExactEvmScheme(account))
const fetchWithPayment = wrapFetchWithPayment(fetch, client)

const body = {
  "url": "https://grist.tools/samples/web/unshorten-start.html",
  "max_hops": 10,
  "follow_meta_refresh": true
}

const res = await fetchWithPayment('https://grist.tools/v1/url-unshorten', {
  method: 'POST',
  headers: { 'content-type': 'application/json' },
  body: JSON.stringify(body),
})
console.log(res.status, await res.json())
const settle = res.headers.get('payment-response')
if (settle) console.log(decodePaymentResponseHeader(settle).transaction)

Python

# url-unshorten: $0.002 per call, paid in USD Coin on eip155:8453 via x402
# Install: pip install "x402[requests,evm]>=2.24,<3"
# The session reads the 402 (payment-required), signs and retries with payment-signature.
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http import decode_payment_response_header
from x402.http.clients.requests import x402_requests
from x402.mechanisms.evm.exact import register_exact_evm_client
from x402.mechanisms.evm.signers import EthAccountSigner

account = Account.from_key(os.environ["EVM_PRIVATE_KEY"])
client = x402ClientSync()
register_exact_evm_client(client, EthAccountSigner(account), networks="eip155:8453")
session = x402_requests(client)

payload = {
    "url": "https://grist.tools/samples/web/unshorten-start.html",
    "max_hops": 10,
    "follow_meta_refresh": True
}

res = session.post("https://grist.tools/v1/url-unshorten", json=payload)
print(res.status_code, res.json())
settle = res.headers.get("payment-response")
if settle:
    print(decode_payment_response_header(settle).transaction)

curl

# url-unshorten: $0.002 per call, paid in USD Coin on eip155:8453 via x402
# 1. Unpaid call: HTTP 402, the requirements in the payment-required header (base64 JSON) and in the body.
curl -i -X POST 'https://grist.tools/v1/url-unshorten' -H 'content-type: application/json' -d '{"url":"https://grist.tools/samples/web/unshorten-start.html","max_hops":10,"follow_meta_refresh":true}'

# 2. Same call with the signed payment (an EIP-3009 authorization, EIP-712 signed: it cannot be
#    typed by hand). x-payment is accepted as the v1 alternative. HTTP 200 carries payment-response.
curl -i -X POST 'https://grist.tools/v1/url-unshorten' -H 'content-type: application/json' -H 'payment-signature: <base64 x402 payload>' -d '{"url":"https://grist.tools/samples/web/unshorten-start.html","max_hops":10,"follow_meta_refresh":true}'

06Errors

Code	HTTP	For this service
invalid_input	400	The body does not match the schema; its fields are url, max_hops, method and follow_meta_refresh.
blocked_target	403
unreachable_target	424
upstream_timeout	424
unprocessable	422
internal	500

Input that is rejected before the tool runs (malformed JSON, schema mismatch, body over the size limit) is never charged.

When each code is raised, and what it means for payment: /docs/url-unshorten.

07Questions

How much does a url-unshorten call cost?: $0.002 per call, paid in USDC on Base via x402, with no account and no API key.
What does url-unshorten return?: A JSON object with 15 top-level fields: requested_url, source_url, final_url, final_status, final_host, final_content_type, hop_count, reached_final, stopped_reason, cross_host, hops, initial_host_is_known_shortener, shortener_list_version, checked_at and fetched_at. The example on this page is a real call over web/unshorten-start.html and web/unshorten-landing.html.
What happens when a url-unshorten call fails?: The tool answers with a typed JSON error from the errors table. Payment is settled only after the tool has produced its result; a call that fails inside the tool is never settled. A 503 upstream_unavailable can follow a settled call; the x402 payments guide covers it, 429, 402 and an uncertain 500.