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

# Apply a fare brand

> Apply a fare family and get the re-priced offer.

The brand is stored on the offer. Create the order with the `offer.offerId` this call returns; nothing else is needed.

## Body

**requestId** `string (uuid)` *required*

`requestId` from search.

**proposalId** `string (uuid)` *required*

The offer's `offerId`.

**fareBrandCode** `string`

The brand's `code` from fare-brands, up to 100 characters. Use it for one-way, combined, and packed offers priced as one.

**leavingFareBrandCode** `string`

Outbound brand `code`, when fare-brands returned separate `leavingFareOptions` and `returningFareOptions` for a packed round trip. Send with `returningFareBrandCode`.

**returningFareBrandCode** `string`

Return brand `code`. Send with `leavingFareBrandCode`.

## Response

**isSuccess** `boolean`

**offer** `Offer`

The re-priced offer. `appliedFareBrand` echoes the code now stored on it.

**dictionaries** `object`

Carrier and airport names, as in search.

## Errors

| HTTP | `errorCode` | Action |
| - | - | - |
| 409 | `CHANGE_PROPOSAL_OPTIONS_FAILED` | The offer expired. Search again. |

```bash cURL theme={null}
curl -X POST "https://api.staging.ttool.travel/hub/api/v1/flights/change-options" \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "requestId": "3f1a1c9e-7b2d-4c7e-9a1f-2b3c4d5e6f70",
    "proposalId": "8d0e3b6a-2f41-4b8e-b1c9-5d6e7f8a9b0c",
    "fareBrandCode": "VALUE",
    "leavingFareBrandCode": null,
    "returningFareBrandCode": null
  }'
```

```json 200 theme={null}
{
  "isSuccess": true,
  "offer": {
    "offerId": "a1b2c3d4-0000-4000-8000-000000000002",
    "hasFareBrands": true,
    "appliedFareBrand": "VALUE",
    "price": { "currency": "USD", "total": 436.00 }
  },
  "dictionaries": { "carriers": { "IA": "Iraqi Airways" }, "airports": {} }
}
```


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