Settlement Verify

settlement-verify

Independent, block-confirmed settlement verification for agent payment rails. Use when you (an AI agent) need to prove that a payout / escrow-release / agent-payment actually SETTLED on-chain — a mined block + verifier fingerprint — rather than only being signed or broadcast. Submit a txid, receive a verification artifact. No KYC, no account, pay-per-verification in USDC (Polygon), post-quantum signed when paid.

When to use

• A counterparty agent claims it released an escrow or paid you — you want proof it mined, not just that it signed.
• You are an escrow / agent-payment rail operator and want a non-repudiable, post-quantum-verifiable settlement confirmation attached to every receipt.
• You need an honest fail-closed check: an unknown or never-mined txid returns a clear NEGATIVE, never a fake success.

What this service is

socseal.xyz hosts an independent settlement-verification service (the settle-prover agent). It answers the question "did this agent-payment actually settle?" with an on-chain-anchored artifact.

• Proof-of-mined: verifies the transaction hit a mined block (block_height>0 AND in_mempool=false). "Accepted into mempool" is NOT settled — the service rejects it with still-in-mempool.
• Post-quantum-signable: verification is sealed with a verifier fingerprint and, when paid, signed with ML-DSA-87 (NIST FIPS-204, quantum-forward-safe). Public key always retrievable at /pubkey for independent offline re-verification.
• Fail-closed: unknown txid → clean negative (not-found). It never fakes success.
• Pay-per-verification, USDC on Polygon: you pay a small USDC amount on Polygon (x402 payment challenge); the service releases the signed artifact only after the payment is block-confirmed on-chain. No credit card, no KYC, no account.
• Free trial: a capped free-trial (2 per address) returns an UNSIGNED verdict + proof-hash so you can prove the rail before paying. Signed artifacts require the paid path.

Endpoints (public, HTTPS)

Base: https://socseal.xyz

How to verify a settlement (the agent flow)

1. Health check: GET https://socseal.xyz/health — confirm "ok":true.
2. Get the public key: GET https://socseal.xyz/pubkey — save the pubkey_hex + pubkey_sha256 for later offline verification.
3. Request a verification: POST https://socseal.xyz/verify with {"txid":"<64-hex>"} → returns HTTP 402 with the x402 payment challenge {accepts:[{network, asset, amount, payTo}]} — the machine-readable USDC price + receive address. (This 402 is the payment prompt, not an error.) For a direct invoice object, POST /invoice with the same txid. (txid is bare 64-hex, 0x optional.)
4. Pay in USDC: send amount_atoms of USDC (native 0x3c499c...) on Polygon to the returned pay_to — the only receive address.
5. Confirm payment: POST https://socseal.xyz/confirm_payment with {"invoice_id":"<sv_...>", "payment_txid":"<0x Polygon txid>", "payer":"<your id>"}. The service block-confirms the USDC payment on-chain; once mined and >= price, it releases the ML-DSA-87-signed artifact {service, txid, mined:true, block_height, checked_at, verifier, signature}.
6. Verify offline (optional): use the /pubkey fingerprint + the artifact's verifier/signature to re-verify with any ML-DSA-87 verifier — no trust in us required.

Honest boundaries (what this service does NOT attest)

• It attests the tx mined on-chain (block height, not mempool).
• It does NOT attest financing terms, single-use, solvency, or settlement finality beyond the block.
• A negative is honest: unknown / never-mined / still-in-mempool txids return a clean negative, never a fabricated success.