Accountable x402 seller kit

Accept the agent payment only after the agent checks out.

x402-style flows can ask an autonomous agent to pay. Gregers adds the seller-side decision layer: verify accountable identity, wallet/payment evidence, policy fit, and receipt binding before a demo API, merchant backend, marketplace or MCP tool would release value.

Public reference/demo only: this gates service release; it does not execute or verify a fresh payment and does not prevent blind wallet transfers.

Open kit JSONTry seller sandboxOpen tool-gate receipt demo
Seller promise
Payment evidence is not enough. The seller needs a reason to serve.

This kit packages the existing Gregers proof surfaces into one operator-readable path: price, verify agent, check policy, bind evidence, then serve with a durable receipt.

Status
Public reference

No new payment, fulfilment, trade, withdrawal, or production tool call is triggered by this page.

Seller decision model

  1. Price or challenge
    Return x402-style terms for the requested resource.
  2. Verify agent
    Check Concordium Agent Registry status and passport.
  3. Check policy
    Resource, purpose, amount, spend cap, expiry and required receipt.
  4. Bind evidence
    Tie recorded fixture or provider-verified payment/wallet evidence to this release decision.
  5. Serve with receipt
    Publish why the seller accepted, challenged or refused.

Included proof surfaces

Agent Acceptance Check

Merchant/counterparty preflight before accepting work, payment or API access.

Open page
x402 Acceptance Sandbox

Seller-side accept, challenge, manual-review and reject scenarios.

Open sandbox
Accountable x402 Tool Gate

Recorded payment evidence plus live Agent Registry passport check before output release.

Open tool gate
Ask Before Pay

Receiving agent asks identity and authority questions before payment terms are released.

Open flow
Agent Wallet Receipt

Accountable agent-wallet payment receipt pattern.

Open receipt
Machine-readable kit

One JSON object for builders: decision model, surfaces, verdicts and boundaries.

Open JSON

Example seller verdicts

registered agent under cap → accept and serve with receiptmissing wallet/card hash → challenge or manual reviewinactive agent → reject before servingpayment seen but policy mismatch → reject before release; refund handling is merchant/provider policy out of scopehigh-risk withdrawal/trade → require explicit human approval

Boundary

This is a Gregers-built public reference kit using Concordium accountable-agent identity evidence. It is not official Concordium/Foundation output and does not claim a Cloudflare, x402, wallet, merchant, data-provider, marketplace, Coinbase, Base, You.com, Glassnode, Mastercard, Crossmint or exchange partnership or production integration. Linked payment evidence may be recorded fixture evidence; production use would replace fixtures with provider/gateway verification and consumed nonce/idempotency state.

GET /api/accountable-x402-seller-kit
kit_hash_sha256: c991d55913829153135773ed397a5de63dac822e5d6e19612e0d29812e8373ae
canonicalization: SHA-256 over UTF-8 canonical JSON, sorted keys, compact separators, excluding kit_hash_sha256
GET /api/agent-acceptance-check?token_id=40&amount=0.25%20USDC&resource=fresh-market-data-api-call&policy=trading-data-freshness-and-spend-cap
GET /api/accountable-x402/receipts/ad999ceafad40e21