Scout: observe an x402 endpoint before your agent pays
Our October 10 staging check reported 49 live x402 observations among 8,308 indexed resources, against 33,702 resources reported by Coinbase Bazaar. This is a partial, nonrandom snapshot, not a marketplace uptime estimate. Unprobed or expired observations are unknown, not evidence that an endpoint is dead.
We operate SpendPreflight. Scout, our endpoint discovery preview, asks what an agent can observe before deciding to pay. Production Scout remains disabled while we work toward our coverage and capacity gates. This article describes the preview, not a completed launch.
Our crawler reads publicly listed resources without payment. It honors robots.txt, spaces requests to each host, and records valid x402 challenges, quoted prices, networks, payees, latency and observation times. Screening adds OFAC and domain signals. A valid challenge proves neither successful paid delivery nor seller identity; informational screening is not legal advice or a compliance certification.
Scout searches service descriptions and tags by task, with price and network filters. Default results exclude high-risk sellers and endpoints lacking current live observations. Trust score sorts first; price breaks ties. The cheapest equally scored quote is not necessarily the cheapest service in the marketplace, nor the best answer to your task.
Scoring combines live observations, payer activity, seller screening, descriptive metadata and listing freshness. Active paid seller monitoring adds a disclosed fifteen-point boost, capped at one hundred. That boost cannot override the default high-risk exclusion. Monitoring is not an endorsement, and screened payees are not automatically paying subscribers.
The intended workflow is find, verify, preflight, then pay. Scout supplies a challenge for review, but your payment client must validate the merchant challenge before signing. Quotes can change. Enforce hold and block decisions in the signing path; merely giving a model a screening tool does not constrain its other payment tools.
The published npm spendpreflight 0.2.0 client includes find and verify helpers for the staging preview. Our live check and preflight services cost $0.01 and $0.02, paid in Base USDC. Scout's configured prices are $0.005 for find and $0.003 for verify. The shared trial allows three calls per IP per UTC day within a deployment; exhaustion never authorizes payment automatically.
We retain no caller request bodies. Discovery observations are timestamped evidence, not permission to spend. Start with the preflight guides and tested buyer examples at docs.spendpreflight.com. We will report production availability, after coverage checks pass and the owner authorizes activation. Until then, treat Scout results as a limited preview.
Snapshot checked October 10, 2026 at 21:57 UTC. Catalog timestamp: 2026-10-10T02:01:14.351Z. Live counts age out; earlier observations are not lifetime uptime. Read the developer guides · Trust and limitations