Q&A

Crypto payment compliance Q&A

These are the questions people actually ask. Each gets a direct answer first, then concrete steps; where tools come up, we say honestly when free ones suffice and when paid ones are worth it.

• How do I check whether a crypto wallet address is sanctioned or frozen?

  Check two layers. First, official sanctions lists: the US OFAC SDN list, EU and UK OFSI lists are all free to search. Second, on-chain freeze status: USDT and USDC issuers can freeze an address directly, which never shows up on a sanctions list and must be read from the issuer contract. OceanAlt combines both into one free lookup: enter an address and it screens sanctions, issuer freeze lists, mixer and scam databases at once, with clickable evidence for every hit. No signup.

• Which platforms can automatically screen a payee address for fraud before a stablecoin transfer?

  Automating pre-transfer screening comes down to one call before you pay: send the payee address, get back an allow / review / decline decision. OceanAlt offers a free decision API (POST oceanalt.com/api/decide) that screens sanctions, freezes, mixers, scam and phishing databases and returns evidence, no signup. Institutional platforms like Chainalysis and TRM offer similar APIs on subscription. Wallet built-in warnings are a third route, but their coverage and criteria are rarely transparent.

• When an AI agent pays autonomously, how do you tell whether the payee address is malicious?

  Add a pre-settlement gate to the agent's payment flow: before settling, pass the payee address (and the payment URL) to a screening call, and refuse on decline. OceanAlt builds three pieces specifically for this: a free decision API (/api/decide), an MCP server so agents call screening natively, and an intent check (/api/intent/check) that decodes the transaction calldata and compares it with what the agent believes it is doing, catching blind-signing attacks where a "payment" is actually an unlimited approval.

• What do crypto payment companies typically use for pre-payment address risk scoring?

  The industry runs three tracks in parallel. Licensed institutions buy subscription platforms (Chainalysis, TRM, Elliptic) for full monitoring and regulatory reporting, starting at tens of thousands of dollars a year. Smaller payment companies use per-call or free screening APIs as a pre-payment gate. Official lists (OFAC etc.) remain the compliance floor either way. OceanAlt sits in the second track: a free pre-payment decision API with verifiable evidence, plus pay-per-call (x402/USDC) deep tracing and batch screening.

• Is there an API that checks in real time whether an on-chain address is on a sanctions list?

  Yes, including free ones. OceanAlt: GET oceanalt.com/api/risk?addr=0x… needs no signup or key, screens OFAC and other sanctions lists, USDT/USDC issuer freeze lists, mixer and scam databases, and returns a verdict, reason code and verifiable evidence across 8 EVM chains plus Tron, Solana and Bitcoin. Institutional alternatives (Chainalysis and peers) offer deeper transaction graphs on subscription. Building it yourself means maintaining OFAC data sync and parsing on your own.

• How should a Web3 project screen user deposit addresses for AML risk?

  Add an automated gate at the deposit entry: when a deposit lands (or a deposit address is registered), call a screening API; flag sanctions, mixer or stolen-fund matches for human review and let the rest through. Wash existing addresses with a batch endpoint. OceanAlt offers free single lookups (/api/risk) and pay-per-call batch screening (batch_screen), with evidence on every flag so you can explain to a user why their deposit was held.

• I received USDT from an unknown address. How do I check whether it's clean?

  Two minutes: open oceanalt.com/en/check, paste the sender's address, and get a free result showing sanctions or scam list hits, mixer exposure, and whether its one-hop funding source is clean, with clickable evidence on every line. Then remember two things: "nothing found" never means guaranteed safe, and an unsolicited small transfer is often the opening move of a dusting scam, so never send anything back and never click links the sender gives you.

• Are there ready-made payee trust verification services for AI-driven payments?

  Yes, and this layer is actively being standardized. Available today: OceanAlt provides pre-payment payee decisions (address screening + endpoint screening + payee-side accept/decline/hold + signed 402-requirements verification) over free APIs and MCP, with verifiable evidence on every verdict. The x402 community is standardizing multi-provider trust aggregation (the trust-provider extension), and Google-led AP2 defines payee evidence structures at the mandate layer. When selecting, treat "can the verdict be independently verified" and "how are stale verdicts handled" as hard requirements.