Pre-spend routing for x402
Find a paid API that works right now.
x402 lets software pay for APIs one request at a time. 402Signal searches Base, Solana, and Algorand, checks the payment options candidates return now, and picks one that fits your rules.
Your app keeps the wallet. It decides whether to pay the seller and make the call.
Base · Solana · Algorand
$0.01 USDC per live routing check. Seller payment is separate.
Example
An agent needs weather data under 2 cents.
A directory finds possible services. 402Signal checks which ones still return usable x402 terms, applies the budget, and returns a route. If none qualify, the agent gets a reason to stop.
One routing check
From a need to a usable route
- 1
Describe the job
Send a capability, a specific URL, and any limits the route must meet.
- 2
Check candidates
402Signal searches supported sources and reads the payment requirements endpoints return now.
- 3
Get a decision
Receive the best qualifying payment option, or a typed reason nothing qualified.
What “works right now” means: the endpoint returned a usable x402 payment offer when checked. It does not guarantee the quality of the seller's paid response.
Why 402Signal
A catalog finds candidates. 402Signal makes a current decision.
For developers
Start with one POST request.
The first response is HTTP 402 with payment options for the routing fee. After payment, 402Signal searches, checks, and ranks candidates.
curl -sS -D - https://402signal.com/route \
-H 'Content-Type: application/json' \
-d '{"need":"weather data","max_price_usd":0.02}'
Algorand MainNet
Anchored
A routing history you can check
402Signal records routing evidence in an append-only Merkle log. Confirmed checkpoints are authorized by a native Falcon-1024 account and anchored on Algorand MainNet. Later changes to the published history can be detected.
Falcon-1024 authorizes the checkpoint transaction. It does not make seller payments or API responses post-quantum secure.