# Defend

## Overview

The `Defend` RPC submits a formal defense against a chargeback dispute. This presents your argument with a reason code to the issuing bank, along with any previously submitted evidence.

**Business Use Case:** After submitting evidence, you must formally contest the dispute before the deadline. This RPC notifies the bank that you are challenging the chargeback and provides your defense reasoning.

## Purpose

**Why formally defend disputes?**

| Scenario                         | Defense Strategy                              | Reason Code                     |
| -------------------------------- | --------------------------------------------- | ------------------------------- |
| **Product delivered**            | Customer received product, delivery confirmed | GOODS\_SERVICES\_RECEIVED       |
| **Valid transaction**            | Customer authorized, 3DS authenticated        | TRANSACTION\_AUTHORIZED         |
| **Refund already issued**        | Customer was already refunded                 | REFUND\_ISSUED                  |
| **Cancellation policy followed** | Customer cancelled outside policy window      | CANCELLATION\_POLICY\_DISCLOSED |

**Key outcomes:**

* Dispute status changes to CHALLENGED
* Defense submitted to issuing bank
* Bank begins review process
* Awaiting final resolution (60-75 days)

## Request Fields

| Field                      | Type   | Required | Description                              |
| -------------------------- | ------ | -------- | ---------------------------------------- |
| `merchant_dispute_id`      | string | Yes      | Your unique dispute reference            |
| `connector_transaction_id` | string | Yes      | Original transaction ID                  |
| `dispute_id`               | string | Yes      | Connector's dispute identifier           |
| `reason_code`              | string | No       | Defense reason code (connector-specific) |

## Response Fields

| Field                   | Type                | Description                                   |
| ----------------------- | ------------------- | --------------------------------------------- |
| `dispute_id`            | string              | Connector's dispute identifier                |
| `dispute_status`        | DisputeStatus       | Updated status: CHALLENGED                    |
| `connector_status_code` | string              | Connector-specific status code                |
| `error`                 | ErrorInfo           | Error details if defense failed               |
| `status_code`           | uint32              | HTTP-style status code                        |
| `response_headers`      | map\<string,string> | Connector-specific response headers           |
| `merchant_dispute_id`   | string              | Your dispute reference (echoed back)          |
| `raw_connector_request` | SecretString        | Raw API request sent to connector (debugging) |

## Example

### Request (grpcurl)

```bash
grpcurl -H "x-connector: stripe" \
  -H "x-connector-config: {\"config\":{\"Stripe\":{\"api_key\":\"$STRIPE_API_KEY\"}}}" \
  -d '{
    "merchant_dispute_id": "dispute_001",
    "connector_transaction_id": "pi_3Oxxx...",
    "dispute_id": "dp_1Oxxx...",
    "reason_code": "goods_services_received"
  }' \
  localhost:8080 \
  types.DisputeService/Defend
```

### Response

```json
{
  "dispute_id": "dp_1Oxxx...",
  "dispute_status": "CHALLENGED",
  "status_code": 200
}
```

## Next Steps

* [Get](https://docs.hyperswitch.io/integrations/prism/api-reference/dispute-service/get) - Check dispute resolution status
* [Accept](https://docs.hyperswitch.io/integrations/prism/api-reference/dispute-service/accept) - Alternative: concede the dispute