Example inputPOST /api/v1/x402/factorial
{
"n": 12
}Portable intent card · utility
Factorial for Agents API for agents
Factorial (n≤20). Call for combinatorics demos and small counting problems with an explicit n cap. Returns n! for n up to 20; larger n returns a structured error. $0.001 USDC per successful call via x402 on Base—deterministic first-party JSON, no API key, no subscription, and nothing is billed on structured validation errors.
Intent to transaction
One command, attributed.
The source header follows this discovery route through challenge, payment and delivery without exposing the buyer or request body.
npx agentcash@latest fetch https://api.delx.ai/api/v1/x402/factorial -m POST -H 'x-delx-source: intent-card-factorial-api' --max-amount 0.001 -b '{"n":12}'Agent discoverydelx/intent-card/v1
{
"intent": "Factorial for Agents for an agent workflow",
"tool_name": "util_factorial",
"price_usdc": "0.001",
"machine_url": "https://commerce.delx.ai/intents/factorial-api.json"
}Portable and inspectable