curl --request POST \
--url https://api.useselo.xyz/v1/preflight \
--header 'Content-Type: application/json' \
--data '
{
"authorizationId": "auth_…",
"targetUrl": "https://api.example.com/v1/orders",
"method": "POST",
"requestBody": {
"sku": "demo-widget",
"quantity": 1
}
}
'{
"eligible": true,
"preflightId": "pfl_…",
"target": {
"url": "https://api.example.com/v1/orders",
"method": "POST",
"priceUsdc": "0.01"
},
"estimatedMaxSpendUsdc": "0.01",
"seloPriceUsdc": "1.00",
"expiresAt": "2026-10-26T12:15:00.000Z"
}Run a preflight
Check, for free, that a target can be tested before you pay. Selo checks the authorization, sends one unpaid request to the target (with requestBody for POST, 10 second timeout, redirects not followed), reads its x402 v2 challenge, and requires an exact USDC payment on Algorand priced at or below the per-job spend limit (0.50 USDC). It also looks the target up in the Bazaar catalog and stores what it finds with the preflight. An eligible preflight is valid for 15 minutes.
curl --request POST \
--url https://api.useselo.xyz/v1/preflight \
--header 'Content-Type: application/json' \
--data '
{
"authorizationId": "auth_…",
"targetUrl": "https://api.example.com/v1/orders",
"method": "POST",
"requestBody": {
"sku": "demo-widget",
"quantity": 1
}
}
'{
"eligible": true,
"preflightId": "pfl_…",
"target": {
"url": "https://api.example.com/v1/orders",
"method": "POST",
"priceUsdc": "0.01"
},
"estimatedMaxSpendUsdc": "0.01",
"seloPriceUsdc": "1.00",
"expiresAt": "2026-10-26T12:15:00.000Z"
}Body
A verified authorization that covers this origin, path and method.
64Absolute https URL of the paid route. A query string is sent to the target; coverage is checked on origin and path.
2048HTTP method Selo uses to call the target.
GET, POST JSON body Selo sends to the target on every request of this test. Only with POST. Any JSON value except null, at most 16 KiB (16384 bytes) once serialized. Omit it to send no body.
Response
The target is eligible.
The target can be tested. Pass preflightId to POST /v1/release-test before expiresAt.
pfl_ plus 26 Crockford base32 characters.
Show child attributes
Show child attributes
What Selo expects to pay the target: one paid request at the target's price.
^[0-9]+\.[0-9]{2,6}$What the release test costs you, paid to Selo over x402.
^[0-9]+\.[0-9]{2,6}$The preflight is valid for 15 minutes.