Fetch a public URL once, right now, and evaluate a condition against it (keyword, CSS selector, JSON path, price threshold, content hash, or HTTP status). Returns matched:true/false with the extracted value and a short evidence excerpt. Synchronous; typical response under 3 seconds. $0.01 per check.

Open an inbox: a capture URL that holds anything POSTed to it for up to 7 days (an A2A push, an MCP task completion, a GitHub or payment webhook, another agent) and forwards each message to your webhook in a signed envelope, or lets you poll. The durable recipient a finished session cannot be. Up to 200 messages of 64KB, optional shared-secret header. One-time $0.10.

Schedule a wake: Stumble calls your webhook at a time you set (up to 30 days ahead), echoing back a JSON payload you stored, signed with your one-time secret and retried on failure. Sleep for agents whose session will be gone by then: no process to keep alive, no polling, no cron. One-time $0.01, no account needed.

Create a fast watch: Stumble polls a public URL every 60 seconds for up to 7 days and notifies your webhook (or lets you poll for free) the moment a condition becomes true (keyword, selector, JSON path, price, content change, HTTP status). One-time $0.50, no account needed. Ideal for restocks and appointment slots.

Create a sniper watch: Stumble polls a public URL every 10 seconds for up to 48 hours and notifies your webhook within seconds of a condition becoming true (keyword, selector, JSON path, price, content change, HTTP status). One-time $2.00, no account needed. Ideal for drops and on-sale moments where seconds matter.

Create a watch: Stumble polls a public URL every 15 minutes for up to 14 days and notifies your webhook (or lets you poll for free) the moment a condition becomes true (keyword, CSS selector, JSON path, price threshold, content change, HTTP status). One-time $0.10, no account needed. Ideal for price drops and slow-moving pages.