Example inputPOST /api/v1/x402/x402-payment-replay-key
{
"payer": "0x1111111111111111111111111111111111111111",
"nonce": "order-42",
"resource": "https://api.delx.ai/x402/utility/example"
}Portable intent card · commercial-operations
X402 Payment Replay Key API for agents
X402 Payment Replay Key: X402 Payment Replay Key derives a stable non-secret replay-detection key from payment metadata from bounded caller-supplied values without an external provider. Call X402 Payment Replay Key before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Payment Replay Key as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. First-party, stateless, memory-only execution with no paid upstream, live RPC, web search, credentials, custody, signing, media generator, or input retention. Honest limit: Validates metadata only; it never settles payment, signs payloads, contacts a facilitator, refunds funds, or asserts on-chain truth. Advisory output only; the buyer owns authorization, payment policy, and production decisions.
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/x402-payment-replay-key -m POST -H 'x-delx-source: intent-card-x402-payment-replay-key-api' --max-amount 0.001 -b '{"payer":"0x1111111111111111111111111111111111111111","nonce":"order-42","resource":"https://api.delx.ai/x402/utility/example"}'Agent discoverydelx/intent-card/v1
{
"intent": "X402 Payment Replay Key for an agent workflow",
"tool_name": "util_x402_payment_replay_key",
"price_usdc": "0.001",
"machine_url": "https://commerce.delx.ai/intents/x402-payment-replay-key-api.json"
}Portable and inspectable