Ephemeral Cloud — disposable infrastructure for autonomous agents
AWS for tasks too small, too temporary, and too autonomous for an AWS account.
Capabilities: WAIT (/v1/watch) - RECEIVE (/v1/webhooks) - WAKE (/v1/callbacks).

No accounts. No API keys. Pay per use via x402 (USDC).

  POST /v1/webhooks                 create a temporary inbound webhook
      body: {"ttl_seconds": 3600, "max_requests": 10}
      -> 402 with x402 v2 payment declaration (PAYMENT-REQUIRED header + JSON body);
         pay and retry with a PAYMENT-SIGNATURE header
      -> 201 {id, url, retrieve_url, read_token, delete_token, expires_at}
  ANY  /w/{id}                      the webhook itself (give this URL away)
  GET  /v1/webhooks/{id}/events     Authorization: Bearer <read_token>
  DELETE /v1/webhooks/{id}          Authorization: Bearer <delete_token>

  POST /v1/callbacks                delayed wake (granularity ~60s)
      body: {"delay_seconds": 1800, "payload": {...}, "callback_url": "optional"}
      payload lands in the mailbox at fire time; poll retrieve_url to collect it.
      callback_url is only POSTed to if it echoes ?x402_challenge=<nonce>.

  POST /v1/watch                    we poll a URL until a condition holds
      body: {"url": "...", "interval_seconds": 300, "expires_in_seconds": 86400,
             "condition": {"type": "json_equals", "path": "$.availability", "value": "available"}}
      conditions: status_changed | content_changed | text_appears | text_disappears | json_equals

Machine-readable description: GET /.well-known/x402
Network: base. First webhook per IP is free (15 min TTL).