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

# Inject Transaction

> Inject a transaction into the watch system for real-time risk evaluation.

<Note>Blnk Watch is currently in beta. [Send us a message](mailto:support@blnkfinance.com)</Note>

When using Watch, use this endpoint to inject a transaction into the service for real-time risk evaluation.

<Note>Any extra Blnk attributes you want rules to use should be sent inside `meta_data`.</Note>

<Info>The field names match Blnk transaction naming — `transaction_id`, `amount`, `currency`, `source`, `destination`, `created_at`, `meta_data` — so mapping from Blnk Core stays predictable. </Info>

### Body

<ParamField body="amount" type="number">
  The transaction amount to evaluate.
</ParamField>

<ParamField body="currency" type="string">
  The three-letter ISO currency code. For example, `USD`.
</ParamField>

<ParamField body="transaction_id" type="string">
  A unique identifier for the transaction. If not provided, Watch generates a UUID.
</ParamField>

<ParamField body="source" type="string">
  The source balance identifier.
</ParamField>

<ParamField body="destination" type="string">
  The destination balance identifier.
</ParamField>

<ParamField body="description" type="string">
  A free-form description of the transaction.
</ParamField>

<ParamField body="created_at" type="string">
  The transaction timestamp in ISO 8601 format. If not provided, Watch uses the current server time.
</ParamField>

<ParamField body="meta_data" type="object">
  Additional metadata as key-value pairs. Use this to pass Blnk attributes needed by your rules.
</ParamField>

<RequestExample>
  ```bash theme={"system"}
  curl -X POST http://localhost:8081/inject \
    -H "Content-Type: application/json" \
    -d '{
      "amount": 5000.00,
      "currency": "USD",
      "transaction_id": "txn_ref_001",
      "source": "balance_123",
      "destination": "balance_456",
      "description": "High-value transfer",
      "created_at": "2026-03-16T09:00:00Z",
      "meta_data": {
        "merchant_category": "finance",
        "country": "US"
      }
    }'
  ```
</RequestExample>

<ResponseExample>
  ```json 200 theme={"system"}
  {
    "transaction_id": "0f81a4e1-2b8d-496b-8d5d-a4e1e980f1a6",
    "message": "Call GET /transactions/{id} to fetch the processed transaction or set ALERT_WEBHOOK_URL to get webhooks when a rule triggers for the transaction."
  }
  ```
</ResponseExample>

***

## Need help?

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To ask questions or discuss issues, please [contact us](mailto:support@blnkfinance.com) or [join our Discord community](https://discord.gg/7WNv94zPpx).

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