Current observation
Routing uses the payment requirements observed during this request, not the metadata a discovery source still publishes.
Find a paid API that works right now.
402Signal searches x402 discovery sources across Base, Solana, and Algorand, probes candidate endpoints immediately before spend, and applies the caller's constraints to the payment options returned by those endpoints. It returns a route only when a current observed option qualifies; otherwise it returns a typed miss.
402Signal does not hold the buyer's keys or execute the selected service's payment.
Base · Solana · Algorand
POST /route · $0.01 USDC per routing check
DISCOVERY
Search supported discovery sources
LIVE CHECK
Probe candidates and parse current HTTP 402 payment requirements
POLICY
Apply caller constraints and rank eligible observed candidates
RESULT
Return selected route and selected_payment, or a typed miss
PQ TRUST
- Commit route evidence to the PQ Trust log. Falcon anchors checkpoints, not merchant payments.
What a paid check does
Constraint enforcement
Caller constraints are applied to those observed options before a winner is selected.
Explicit failure modes
When no observed option qualifies, the response is a typed miss that reports why evaluation stopped.
Execution boundary
The caller retains custody of keys, signing, the selected service's payment, and execution of that service.
Algorand MainNet
Awaiting checkpoint
Verifiable routing history
PQ Trust is 402Signal's append-only transparency layer. Routing evidence is committed to an append-only Merkle log.
Falcon anchors checkpoints, not merchant payments.
Later rewriting inconsistent with published checkpoints becomes detectable.
Public directories
402Signal is currently listed in the following public directories and registries.
Glama MCP Registry Gold-402 Smithery Agentic Market x402-dev GoPlausible
These links confirm directory presence; they are not endorsements.