> ## Documentation Index
> Fetch the complete documentation index at: https://developers.circle.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Quickstart: Assess the risk of wallet addresses

Transaction Screening allows you to programmatically assess the risk of wallet
addresses when sending digital assets using Circle Wallets. This guide walks you
through setup, integration, and testing using Circle's Compliance Engine.

This guide applies specifically to the
[standalone screening](/wallets/compliance-engine/tx-screening#standalone-screening)
mode, where blockchain addresses are screened independently of transaction
flows.

<Note>
  Compliance Engine on both testnet and mainnet is only available for eligible
  customers. Contact Circle through the
  [Compliance Engine request form](https://www.circle.com/wallets/compliance-engine/#get-in-touch)
  to get access.
</Note>

## Prerequisites

Before you begin, make sure you have the following:

* A Circle Developer Account
* An API key with appropriate access to
  [Compliance Engine](https://console.circle.com/compliance)
* [Node.js](https://nodejs.org/en/download) installed, or an API tool like
  Postman or cURL
* [Axios](https://axios-http.com/) installed, if using Node.js

## Steps

Follow the steps below to screen an address:

### 1. Generate a test address

To simulate a real screening scenario, visit
[vanity-eth.tk](https://vanity-eth.tk) to generate a test Ethereum wallet
address ending in `9999`:

For example, `0x7fb49965753A9eC3646fd5d004ee5AeD6Cc89999`.

The `9999` suffix triggers Circle's sanctions blocklist in the screening API.

### 2. Screen the wallet address explicitly using Circle's API

Submit a `POST` request to the screening API using Node.js:

```javascript JavaScript theme={null}
import axios from "axios";

const options = {
  method: "POST",
  url: "https://api.circle.com/v1/w3s/compliance/screening/addresses",
  headers: {
    Authorization: "Bearer <API_KEY>",
    "Content-Type": "application/json",
  },
  data: {
    idempotencyKey: "44bd2d89-9461-4502-84ba-550c9e278db7", // unique-idempotency-key
    address: "0x7fb49965753A9eC3646fd5d004ee5AeD6Cc89999",
    chain: "ETH-SEPOLIA",
  },
};

axios
  .request(options)
  .then(function (response) {
    console.log(response.data);
  })
  .catch(function (error) {
    console.error(error);
  });
```

<Note>
  **Note:** You must replace the `<API_KEY>` above with your actual Circle API
  key.
</Note>

### 3. Review the screening response

If the address is flagged, the response returns a `DENIED` result with some
actionable compliance recommendations:

```json JSON theme={null}
{
  "result": "DENIED",
  "decision": {
    "ruleName": "Circle's Sanctions Blocklist",
    "actions": ["FREEZE_WALLET", "DENY", "REVIEW"],
    "reasons": [
      {
        "source": "ADDRESS",
        "sourceValue": "0x7fb49965753A9eC3646fd5d004ee5AeD6Cc89999",
        "riskScore": "BLOCKLIST",
        "riskCategories": ["SANCTIONS"],
        "type": "OWNERSHIP"
      }
    ],
    "screeningDate": "2025-03-29T01:59:02Z"
  },
  "address": "0x7fb49965753A9eC3646fd5d004ee5AeD6Cc89999",
  "chain": "ETH-SEPOLIA"
}
```

### 4. Evaluate screening recommendations

If the screening result is `DENIED`, you can take the following actions based on
the recommendations provided:

* **Block** the wallet from transaction activity (based on the `DENY`
  recommendation)
* **Flag** the wallet for manual review (based on the `REVIEW` recommendation)
* **Freeze** the wallet (based on the `FREEZE_WALLET` recommendation)

<Note>
  You can **block** or **freeze** the wallet from the [Compliance Engine >
  Alerts](https://console.circle.com/compliance/alerts/screening) page in the
  Developer Console. For more details, see the [Alerts
  Management](/wallets/compliance-engine/tx-screening-alert-management)
  documentation.
</Note>

## Automate rules based on screening outcomes

You can integrate
[actions and alerts](/wallets/compliance-engine/tx-screening-rule-management)
into the transaction logic of your application:

```javascript JavaScript theme={null}
if (response.data.result === "DENIED") {
  const ruleName = response.data.decision.ruleName;
  const actions = response.data.decision.actions;

  console.log("Screening result: DENIED by Rule: " + ruleName);

  if (actions.includes("DENY")) {
    console.log("Recommended action: DENY — block transactions on wallet");
  }

  if (actions.includes("REVIEW")) {
    console.log("Recommended action: REVIEW — flag wallet for manual review");
  }

  if (actions.includes("FREEZE_WALLET")) {
    console.log("Recommended action: FREEZE_WALLET — freeze wallet activity");
  }
}
```

You can also query additional fields such as `riskCategories`, `ruleName`, and
`type` to make compliance decisions tailored to your business needs. For more
information about these fields, refer to their descriptions in the response
object of the
[Screen a blockchain address](/api-reference/wallets/compliance/screen-address)
API endpoint.

## Testing with simulated risk categories

You can use specific suffixes in test addresses to simulate different risk
scenarios:

| Suffix | Simulated Rule Triggered           |
| ------ | ---------------------------------- |
| `9999` | Circle's Sanctions Blocklist       |
| `8888` | Frozen User Wallet                 |
| `7777` | Custom Blocklist Rule              |
| `8999` | Severe Sanctions Risk (Owner)      |
| `8899` | Severe Terrorist Financing (Owner) |
| `8889` | Severe CSAM Risk (Owner)           |
| `7779` | Severe Illicit Behavior (Owner)    |
| `7666` | High Illicit Behavior Risk (Owner) |
| `7766` | High Gambling Risk (Owner)         |

<Note>
  **Test suffixes** are useful in pre-production environments for validation of
  custom rule enforcement and behavior.
</Note>