FinalSentry for agents
Independent website release evidence with exact native USDC payments on Base mainnet.
Quick: 0.099 USDC · eligible intro 0.01 USDC
The browser engine checks desktop (1365×900) and mobile (390×844) rendered pages, captures viewport screenshots, checks horizontal overflow and visible broken images, records JavaScript and network errors, and inspects form validation. It follows at most one safe same-origin checkout link. Findings include exact evidence and repair actions.
Browser provider connected: live Chromium checks passed on FinalSentry’s production page and the dedicated sandbox. Check current availability. Desktop/mobile screenshots, sandbox form submission and checkout reachability were verified on 11 October 2026.
Introductory terms: one completed Quick report per wallet; previous introductory purchases count towards eligibility. Global launch budget: 100 discounted reports. Unresolved attempts reserve slots; failed runs without settlement release them. Anonymous requests advertise the standard price. Full pricing menu.
Acceptance and Journey
Acceptance costs 0.299 USDC for up to three same-origin pages and ten explicit requirements. Journey costs 0.999 USDC for one configured staging journey with up to ten steps and a final outcome assertion. See the package guide and request examples. Requests exceeding limits or targeting unapproved staging origins are rejected before payment.
Forms and checkout
Public mode blocks writes. Empty-field validation and checkout page loading do not establish successful submission or payment completion. For an actual submission test, use an owner-configured sandbox origin, allowed test API paths and an explicit journey with a visible success assertion. Buyers cannot turn a public site into an approved sandbox.
Live purchase submission is blocked. Browser emulation is not a physical iPhone test. Screenshots cover the initial viewport; visual aesthetics, login, exhaustive accessibility and security are outside scope.
Agent introductory purchase · 0.01 USDC
POST /api/browser-intro with {"url":"https://your-public-site.com/"}. Read the 402 challenge, verify 10000 atomic Base USDC and the receiver, then retry the same body with your authorized PAYMENT-SIGNATURE. This endpoint requires no payer field or separate signed quote. One report per wallet and 100 globally, counting previous introductory purchases and unresolved reservations. If ineligible, it returns 409 without settlement; it never switches you to a higher price. Retain the same authorization for recovery.
Reuse your acceptance requirements
Use the check planner to save a URL and up to four expected text phrases on your device. Copy the prepared request to your agent. The acceptance helper supports explicit selectors and maps report evidence to passed, failed or untested requirements. Assertions currently run in mobile Chromium; desktop rendering checks remain separate. A new verification run is a new paid report.
Request and payment
POST /api/browser-scan
Content-Type: application/json
{"url":"https://your-public-site.com/","mode":"readonly"}While unavailable, the endpoint returns 503 with no settlement. After connection, an unpaid request returns HTTP 402 with PAYMENT-REQUIRED. Verify eip155:8453, native USDC, amount 10000 or 99000 for Quick, 299000 for Acceptance, or 999000 for Journey and the receiver before signing. The helper enforces a separate exact price ceiling for the selected package. Include payer in the unpaid request to obtain a signed five-minute quote and its canonical request body. Sign the advertised terms, then submit exactly that quoted body without the payer field. Intro slots are reserved atomically after signature verification; concurrent attempts count until resolved.
Receiver: 0xf9f63ab1cf910b1f45a528b6c047cdb2f5df411f
Browser evidence is prepared before settlement. A failed run returns an error without settlement. A useful report containing detected defects is a completed audit and is chargeable. No report is released until the exact payment is confirmed on-chain.
Persist one authorization before submission. HTTP 202 or an ambiguous error requires the identical request and authorization. Identical delivered retries return the saved report without another browser run or charge. Never sign a replacement to resolve an ambiguous outcome.
Use the official x402 SDK purchase helper with your existing signer, a durable exclusive task lock, and loadAttempt/saveAttempt callbacks. The saved attempt must survive process restarts; keep it after success and ambiguous failures.
Capacity and retention
One browser job runs at a time. Limits are three runs per wallet per rolling 24 hours, 20 total per 24 hours and 400 per 31 days, including failed runs. Each job allows at most 60 network resources, each up to 1 MiB. Capacity or provider failure does not settle payment.
Page requests use a backend HTTPS relay that validates IPv4 and IPv6 DNS answers and pins each TLS connection to a validated public IPv4 address. Authentication cookies are not forwarded; affected sites require review. Unsupported or blocked resources are recorded.
Reports, screenshots and stored payment authorisations expire after seven days. Cleanup runs hourly; deletion can take up to one additional hour. Payment nonce hashes and transaction references remain to prevent duplicate payments. Export reports you want to keep.
Original payment validation
The existing /api/paid-scan HTML report and isolated tester retain their original 2 USDC terms for compatibility. They do not provide browser evidence. On 11 October 2026, the 0.009 USDC browser route completed a Base mainnet owner self-payment and delivered its saved desktop/mobile report. Transaction: 0x8c5b7b28c3e5953e2877f4f4cfb054ff687e768320afb9e92e841a0a1d9ff4a5. This verifies payment and report delivery; it does not prove customer demand or live purchase completion.