# Post-authenticate

## Overview

The `PostAuthenticate` RPC validates 3D Secure authentication results with the issuing bank. After the customer completes a challenge (if required), this RPC confirms the authentication was successful and returns the data needed to proceed with payment authorization.

**Business Use Case:** After the customer returns from a 3DS challenge or after a frictionless authentication, you need to validate the results before processing the payment. This RPC confirms the authentication and provides the ECI and CAVV values required for liability shift.

## Purpose

**Why post-authenticate?**

| Scenario                       | Action                               |
| ------------------------------ | ------------------------------------ |
| **After challenge completion** | Validate the authentication response |
| **Before payment**             | Confirm authentication succeeded     |
| **For liability shift**        | Obtain ECI/CAVV values               |

**Key outcomes:**

* Authentication validated
* ECI and CAVV values returned
* Ready for payment authorization

## Request Fields

| Field                          | Type               | Required | Description                          |
| ------------------------------ | ------------------ | -------- | ------------------------------------ |
| `merchant_order_id`            | string             | Yes      | Your unique order reference          |
| `amount`                       | Money              | Yes      | Transaction amount                   |
| `payment_method`               | PaymentMethod      | Yes      | Card details                         |
| `customer`                     | Customer           | No       | Customer information                 |
| `address`                      | PaymentAddress     | Yes      | Billing address                      |
| `authentication_data`          | AuthenticationData | No       | 3DS result data from challenge       |
| `connector_order_reference_id` | string             | No       | Connector's order reference          |
| `metadata`                     | SecretString       | No       | Additional metadata                  |
| `connector_feature_data`       | SecretString       | No       | Connector-specific metadata          |
| `return_url`                   | string             | No       | URL to redirect after authentication |
| `continue_redirection_url`     | string             | No       | URL to continue after redirect       |
| `browser_info`                 | BrowserInformation | No       | Browser details                      |

## Response Fields

| Field                               | Type                | Description                               |
| ----------------------------------- | ------------------- | ----------------------------------------- |
| `connector_transaction_id`          | string              | Connector's authentication transaction ID |
| `status`                            | PaymentStatus       | Current status: AUTHENTICATED, FAILED     |
| `error`                             | ErrorInfo           | Error details if validation failed        |
| `status_code`                       | uint32              | HTTP-style status code                    |
| `response_headers`                  | map\<string,string> | Connector-specific response headers       |
| `redirection_data`                  | RedirectForm        | Additional redirect if needed             |
| `network_transaction_id`            | string              | Card network transaction reference        |
| `merchant_order_id`                 | string              | Your order reference (echoed back)        |
| `authentication_data`               | AuthenticationData  | Validated 3DS authentication data         |
| `incremental_authorization_allowed` | bool                | Whether incremental auth is allowed       |
| `state`                             | ConnectorState      | State for payment authorization           |
| `raw_connector_response`            | SecretString        | Raw response for debugging                |

## Example

### Request (grpcurl)

```bash
grpcurl -H "x-connector: stripe" \
  -H "x-connector-config: {\"config\":{\"Stripe\":{\"api_key\":\"$STRIPE_API_KEY\"}}}" \
  -d '{
    "merchant_order_id": "order_001",
    "amount": {
      "minor_amount": 10000,
      "currency": "USD"
    },
    "payment_method": {
      "card": {
        "card_number": "4242424242424242",
        "expiry_month": "12",
        "expiry_year": "2027"
      }
    },
    "address": {
      "billing_address": {
        "line_1": "123 Main St",
        "city": "San Francisco",
        "country": "US"
      }
    },
    "authentication_data": {
      "eci": "05",
      "cavv": "AAABBIIFmAAAAAAAAAAAAAAAAAA="
    }
  }' \
  localhost:8080 \
  types.PaymentMethodAuthenticationService/PostAuthenticate
```

### Response

```json
{
  "connector_transaction_id": "pi_3Oxxx...",
  "status": "AUTHENTICATED",
  "authentication_data": {
    "eci": "05",
    "cavv": "AAABBIIFmAAAAAAAAAAAAAAAAAA=",
    "trans_status": "Y"
  },
  "incremental_authorization_allowed": false,
  "status_code": 200
}
```

## Next Steps

* [Payment Service](https://docs.hyperswitch.io/integrations/prism/api-reference/payment-service) - Authorize payment with 3DS data