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Shonin
Beta

Shonin Receipt

Proof for every agent payment: an on-chain settlement check and a signed, normalized receipt for the books.

The split

LLM writes
Nothing
System One decides
Nothing: receipts are exact
Code executes
Chain reads, log decoding, matching and signing

Engine

Code only: it reads the transaction from the chain, decodes the stablecoin transfer and the EIP-3009 authorization, compares them with what you expected, and signs the result.

Rulebook

What correct means here, and the mistakes we've already caught. It grows one job at a time.

  1. R01Only known stablecoins count as payments; other token transfers are ignored.
  2. R02A reverted or missing transaction is reported as such, never as settled.
  3. R03Receipts are signed over sorted-key JSON, so anyone can verify them.

Endpoint

POST /api/v1/receipt  # $0.01 per call, USDC via x402

{
  "network": "eip155:42220",
  "transaction": "0xf6f71df2f84279c483b138a43c8adcfcd7c1e319459f2b1b2497cdb706a38b38"
}

Intake

  • The PAYMENT-RESPONSE header, or the network and transaction hash
  • Optional: the payee, amount and payer you expected
UNIT
One verified receipt for one payment
REVIEW LAYER
Automated: every expectation the caller sent comes back as matched or not.
DELIVERY
A JSON receipt with an explorer link, signed when a receipt key is configured.
TURNAROUND
A few seconds

How we find buyers

  • x402 Bazaar, llms.txt and the agent card
  • MCP registries
  • x402 sellers who want receipts for their buyers
  • Finance teams of companies running paying agents

More like this

BetaAgent API

Shonin Check

Should my agent pay this? A pre-payment check of any x402 payment request: pay, confirm with a person, or block.

UNIT
One check of one payment request
PRICE
$0.01 per check
Under a second without a task; a few seconds with the intent checkOpen
BetaAgent API

Shonin Gate

Execute, confirm or escalate? An approval gate for any agent action, with one confidence bar per risk tier.

UNIT
One gate decision for one proposed action
PRICE
$0.01 per gate
A few secondsOpen
SoonAgent API

Decide API

Typed decisions for agents: Choice, Score and Noul with confidence, in one call, paid per call.

UNIT
One decision call: up to 16 questions over up to 8k tokens of state
PRICE
$0.01 per decision
~100–800 msOpen