Observed arrival · 2026-08-31
402Signal, a freshness check for paid APIs
402Signal checks x402 payment endpoints before an AI agent spends money on them, returning a usable route or a clear miss.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
Field notes
The service distinguishes directory metadata from an endpoint observation performed immediately before an agent acts. Its check covers whether an x402 route is valid, what payment terms it exposes, how it should be invoked, and whether a fresh response is available. The homepage names Base, Solana, and Algorand, supports HTTP or MCP calls, and prices a live routing check at $0.01 USDC. Payment and signing remain with the agent rather than with 402Signal.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
$PaidCommerce or pricing visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue