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

# Card Transaction Monitoring

> Real-time fraud assessment for card transactions using algorithmic analysis and spending pattern detection.

## Overview

The Card Transaction Monitoring system performs real-time fraud assessments on card transactions. Each transaction receives a activity code — a calculated risk indicator — which you can use to flag, review, or auto-reject suspicious activity.

## How It Works

<Steps>
  <Step title="Submit the transaction">
    Send transaction details to the [Post Fraud Request](/v3/transaction/card_transaction/post_fraud_request) endpoint.
  </Step>

  <Step title="Algorithmic analysis">
    The system evaluates transaction characteristics including location, transaction history, and spending patterns.
  </Step>

  <Step title="Real-time assessment">
    An activity code is returned immediately, reflecting the outcome of the fraud assessment.
  </Step>

  <Step title="Take action">
    Use the returned activity code to approve, flag for manual review, or auto-reject the transaction.
  </Step>
</Steps>

## Key Features

<CardGroup cols={2}>
  <Card title="Real-Time Assessment" icon="bolt">
    Activity codes are returned instantly, enabling immediate action on suspicious transactions.
  </Card>

  <Card title="Spending Pattern Analysis" icon="chart-bar">
    Detects anomalies by comparing each transaction against historical spending behaviour.
  </Card>

  <Card title="Location Intelligence" icon="location-dot">
    Flags transactions from unusual or high-risk locations.
  </Card>

  <Card title="Actionable Results" icon="sliders">
    Use the returned activity code to configure your own approve, flag, or reject logic based on your risk appetite.
  </Card>
</CardGroup>

## Endpoints

| Endpoint                                                                  | Description                                              |
| ------------------------------------------------------------------------- | -------------------------------------------------------- |
| [Post Fraud Request](/v3/transaction/card_transaction/post_fraud_request) | Submit a card transaction for real-time fraud assessment |

## Rule Criteria

Fraud rules can be based on any combination of the following:

| Criterion             | Example                                                    |
| --------------------- | ---------------------------------------------------------- |
| Transaction amount    | Flag any transaction over \$5,000                          |
| Transaction frequency | Flag more than 5 transactions in 10 minutes                |
| Geographic location   | Flag transactions from high-risk countries                 |
| Merchant category     | Flag gambling or crypto merchant codes                     |
| Time of day           | Flag transactions between 1am–4am                          |
| Account type          | Apply different rules to individual vs. corporate accounts |

## Activity Codes

**Suspicious (flag for review):**

| Code  | Description                                                 |
| ----- | ----------------------------------------------------------- |
| `450` | Suspicious Transaction Detected — Requires Manual Review    |
| `451` | High-Risk Transaction — Potential Fraud                     |
| `452` | Unusual Transaction Behavior — Pattern Anomaly              |
| `453` | Velocity Check Failed — Too Many Transactions in Short Time |
| `454` | Geographic Inconsistency — Unusual Location                 |
| `455` | Transaction Amount Too High — Above Threshold               |
| `456` | Blacklisted Account or Entity                               |
| `457` | Repeated Failed Transactions — Possible Fraud Attempt       |

**Safe:**

| Code  | Description                                                    |
| ----- | -------------------------------------------------------------- |
| `200` | Transaction Approved — No Issues                               |
| `201` | Transaction Successfully Processed                             |
| `202` | Transaction Pending Review — Routine Check                     |
| `210` | Trusted Transaction — Verified and Safe                        |
| `211` | Low-Risk Transaction — No Anomalies Detected                   |
| `212` | Recurring Transaction Approved — Previously Authorized Pattern |
| `220` | Whitelisted Entity — Pre-approved Account or Business          |
| `221` | Known Customer — Transaction Aligns with User History          |

## Webhook Notifications

When a card transaction is flagged, Adhere sends a `suspicious_transaction` event to your configured webhook URL. See [Webhooks](/webhooks) for the full payload structure and signature verification guide.

## Next Steps

<CardGroup cols={2}>
  <Card title="Submit a Transaction" icon="paper-plane" href="/v3/transaction/card_transaction/post_fraud_request">
    Send your first card transaction for fraud assessment.
  </Card>
</CardGroup>