Run an AML compliance screen on a single blockchain address BEFORE paying or receiving from it. Checks OFAC sanctions, known mixers, community scam/phishing lists, stablecoin issuer freezes (USDT on Tron, USDC on EVM chains), and on-chain heuristics (address age, activity, one-hop taint from flagged addresses) where the chain supports them. Returns a verdict (clear | caution | risky), a 0–100 risk score, a blocked flag, and clickable verifiable evidence showing which list/label/on-chain path matched — receipts, not a black-box score. A clear verdict means nothing was found in the data OceanAlt holds; it is not a statement that the address is safe. Screening depth varies by chain (see coverage.chains at https://oceanalt.com/.well-known/agent-capabilities). Supports EVM (0x…), Tron (T…), and Solana (base58). Free, no API key, no signup.

The other half of a safe agent payment. Before settling, ask the registered payee (by its OceanAlt registry sid — see https://oceanalt.com/registry.json) whether it accepts this incoming payment. Returns status accept | decline | hold_request_info | not_ready, machine-readable reason codes, requested_fields (only on hold), verifiable evidence and a signature. Rule-based, not model judgement: payee readiness comes from the public registry enforcement ladder (https://oceanalt.com/en/registry/rules), the payer address is screened in reverse, and amount / purpose / KYA requirements come from the payee's own policy. decline is final — re-paying does not change it. Free, no API key.

Answers a different question from address screening. Screening asks whether an address is risky; this asks how much damage the agent on the other side could do if it were talked into something — whether a spending ceiling exists, whether payees are restricted, whether its credential can be revoked. It returns that party's self-attestation against the OceanAlt Agent Control Baseline, split into two sets that must NOT be conflated: verified_by_oceanalt (controls the gateway enforces on every payment — provable) and self_claimed (what the party states about its own side — NOT verified by OceanAlt). IMPORTANT: most parties have not attested. A result of found:false means no information, not a bad signal — never decline a payment on that basis alone. Free, no API key.

Resolves who stands behind a paying agent: agent → principal → mandate → credential → wallet. Each link reports whether it holds, and completeness counts how many do — it is a factual count, not a score. Wherever the chain breaks is where accountability stops, which is what you actually need to know before accepting a payment from an autonomous agent. Publication is opt-in and only posture is exposed (that a ceiling exists, never its value), so found:false means the agent has not published — absence of information, not a bad signal. Free, no API key.

Return a representative sample of addresses on OceanAlt's reviewed risk list — OFAC-sanctioned, known mixers, and community-reported scam/phishing — each with its source category and the reason it was flagged. Useful for grounding, showing an agent/user what gets blocked and why, or a quick read on the current threat surface. Takes no arguments. Free, no API key.

"Before your agent pays, call OceanAlt once." Pass the payee address the agent is about to pay; get a machine-executable decision: allow | review | decline, plus verifiable evidence and retry semantics. Use this as a gate in an autonomous payment flow — if the decision is not "allow", do not pay. On allow/review it also returns a verifiable compliance attestation you can attach to the settlement so the payment carries proof it passed OceanAlt's decision. Free, no API key, no signup. (For the paid variant that also settles the payment on x402 rails, use compliance_decision.)

Anti blind-signing. EVM: decodes what calldata will actually do (ERC-20 transfer/approve/permit, setApprovalForAll, ownership transfer, native transfer). Solana: decodes a whole base64 transaction (SPL Token / Token-2022 Transfer, TransferChecked, Approve, SetAuthority, CloseAccount, Burn; System Transfer / Assign; ATA creation). Compares it with the payment the agent believes it is making. decision match = does what you declared; mismatch = different recipient/amount/asset, or an approval / authority change instead of a payment — do not sign; unknown = could not decode (including address-lookup-table accounts), which is NOT the same as safe. Free, no API key.

A 402 response is plaintext: any hop between seller and agent (proxy, CDN, a compromised SDK, a malicious tool) can swap the payTo address. Sellers who sign their payment requirements with OceanAlt put extensions.signedRequirements (Ed25519) inside the PAYMENT-REQUIRED header payload. Pass the decoded header JSON (or its raw base64) and, optionally, the payTo / amount you expect; get verified true/false with a reason code: ok | no_signature | digest_mismatch | signature_invalid | key_unavailable | payto_mismatch | amount_mismatch. Defends against tampering in transit, not against a compromised seller origin. Free, no API key.

Everything OceanAlt can say about an address, in one Ed25519-signed bundle you can verify offline: screening verdict + evidence + freshness, self-built profile signals, one-hop relations to listed addresses, fulfillment receipt stats. OceanAlt is a witness, not a plaintiff: no conclusions, no attribution of persons, every item carries its source and coverage date. Everything inside is already public; there is no user data and no privileged channel — anyone may request one. Free, 10 per minute.

Screen a payment ENDPOINT (URL or domain) before calling it — the half that address screening cannot answer. In x402 the agent discovers a URL first, receives a 402, and only then learns where to pay: if that endpoint is spoofed, the payee address it hands back is freshly generated and appears on no sanctions list. Checks the hostname and its parent domains against public phishing-domain lists plus hostname shape signals. Returns clear | caution | risky | unknown with language-independent signal_keys. clear means no match was found, NOT that the endpoint is safe. Use together with screen_address. Free, no API key.

Fetch the OceanAlt Agent Control Baseline: the controls an agent operator is expected to run before it is allowed to move money, each answerable yes or no. Call this before attest_control_baseline so you file against real control ids. Each control says which layer enforces it.

File your operator's control-baseline attestation — the counterpart to counterparty_control_baseline. That tool asks what controls the OTHER side runs; this one publishes what YOUR side runs, so payers can see it before settling with you. No account, no key, one call. Gaps are allowed: answer false where a control is not in place and describe the plan in gapPlan. Get the control ids from baseline_controls first. Only file for a party you are actually authorised to speak for.

Run OceanAlt's full compliance gateway on a proposed payment and get a DECISION — allow | review | decline — plus advice and verifiable evidence, not just raw data. Combines AML screening of the payee with RAP (Responsible Agentic Payments) gate checks. Use this when an agent needs a go/no-go call before releasing funds. PAID via x402: the first request returns HTTP 402, this server automatically signs one USDC authorization and retries — this moves REAL money and requires OCEANALT_PAYER_KEY. Costs $0.002 in real USDC settled on Base mainnet (eip155:8453). Alternatively set OCEANALT_CREDIT_TOKEN (a credit pack bought at POST https://oceanalt.com/api/x402/credits: $0.10 for 100 decisions); each call then uses one credit and no payment is signed. Always confirm the live network/price at https://oceanalt.com/api/x402 and use a dedicated low-balance payer wallet.

Trace a Tron (TRON) USDT address up to 3 hops back along its largest incoming transfers to see whether its funds touch a Tether-frozen, sanctioned, mixer, or scam address upstream — deeper than a single-address screen. Tron only (T…). PAID via x402: moves REAL money and requires OCEANALT_PAYER_KEY. Costs $0.01 in real USDC settled on Base mainnet (eip155:8453) — confirm the live network/price at https://oceanalt.com/api/x402 and use a dedicated low-balance payer wallet. Note: follows only the main funds path, depth ≤3, not exhaustive — no hit does not prove the address is clean.

Screen up to 25 blockchain addresses in a single call. Returns a per-address verdict (clear | caution | risky | invalid), risk score, blocked flag, and top signal, plus a summary count, sorted risky-first. Cheaper per address than screening one at a time. EVM (0x…) and Tron (T…). PAID via x402: moves REAL money and requires OCEANALT_PAYER_KEY. Costs $0.01 in real USDC settled on Base mainnet (eip155:8453) — confirm the live network/price at https://oceanalt.com/api/x402 and use a dedicated low-balance payer wallet.