> ## Documentation Index
> Fetch the complete documentation index at: https://circle-devdocs-test-ai-codegen-component.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Quickstart: Assess the Risk of Wallet Addresses

Circle's **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**.

<Note>
  **Note:** 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>

## 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) (all testnet keys
  have this access by default)
* [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:

```text theme={null}
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>