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x402 Delayed HTTP Callback Scheduler
x402
x402 Delayed HTTP Callback Scheduler is a paid API for AI agents from x402-paywall.huntercarver24.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-31).
Schedules a one-time delayed HTTP callback to any public URL, firing a GET or POST request after a specified delay (60 seconds to 7 days) or at an absolute time, with one retry and a 10-second timeout.
Price / call$0.005
Success—
StatusUnknown
How this service works
Schedules a delayed HTTP callback: give a public URL, an optional JSON body, optional headers and a delay of 60 seconds to 7 days (or an absolute time), and this host calls the URL at that time (POST when a body was given, otherwise GET), with one retry and a 10-second timeout. GET /later/<id> reports whether it fired and the status code the callee answered. A request that is refused is not charged.
Output
Returns a callback ID on successful scheduling. A GET to /later/<id> returns whether the callback has fired and the HTTP status code returned by the target URL. If the request was refused (invalid URL, private address), it is not charged.
Example use cases
Post-payment delayed notification
“After this order is confirmed, schedule a POST callback to https://fulfillment.mystore.com/orders/ready in 5 minutes with body {"orderId": "ORD-9921", "status": "confirmed"} so the warehouse system picks it up.”
Timed reminder ping to agent endpoint
“Set up a GET callback to https://agent.mycompany.com/nudge?task=daily-report in exactly 3600 seconds so my agent wakes up and runs the daily report.”
Absolute-time scheduled webhook
“Schedule a POST to https://notifications.myapp.io/send at 2026-06-15T09:00:00Z with the JSON body {"message": "Campaign is live!", "campaignId": "cp-42"} and a header X-Secret of 'mysecret99'.”
Technical details
Endpoint
POSThttps://x402-paywall.huntercarver24.workers.dev/later?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to fire a one-time HTTP callback to a public URL at a precise future time or after a specified delay, without running your own cron infrastructure. Ideal for webhook-based workflows, post-processing triggers, or timed notifications in serverless or agent pipelines. Prefer this over polling-based approaches or custom scheduled jobs when you need a lightweight, pay-per-use scheduled HTTP call with delivery confirmation.
Side effects
- Private, local, or cloud-metadata target URLs are refused at scheduling and again at fire time
- Redirects from the target URL are reported but not followed
- Callee does not respond within 10-second timeout — one retry is attempted
- Body exceeds 65536 bytes serialized
- More than 16 custom headers provided
- Header values contain non-printable ASCII or exceed 1024 characters
- Forbidden headers (host, content-length, connection-level) are rejected
- Both delaySeconds and at are provided simultaneously — refused
- Delay is less than 60 seconds or more than 7 days (604800 seconds)
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| at | string | Absolute time with a timezone, e.g. 2026-10-28T15:00:00Z, 60 seconds to 7 days ahead. Give this or delaySeconds, not both. |
| url | string | Public http(s) URL to call. Private, local and cloud-metadata addresses are refused, when scheduled and again when fired. Redirects are reported, not followed. |
| body | — | Any JSON value. Present: the callback is a POST with this as its JSON body. Absent or null: a GET. Up to 65536 bytes serialised. |
| headers | object | Extra request headers, printable ASCII values up to 1024 characters. host, content-length and connection-level headers are refused. |
| delaySeconds | integer | Seconds from now. Give this or at, not both. |
Tags
x402
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