## Update contact

`PATCH https://whatsapp.paaltech.org/api/v1/businesses/{external_id}/contacts/{id}`

Change a contact's details, custom fields (`null` clears one) or tags (replaced).

Ability: `contacts.write`

### Path parameters

| Name | Type | Required | Description |
|---|---|---|---|
| `external_id` | string | yes | Your own ID for the business (Multi-SKUUL - the tenant ID). Max 191 characters. Pattern `^[A-Za-z0-9._:-]+$` |
| `id` | integer | yes | PaalChat's contact ID. |

### Body

| Name | Type | Required | Description |
|---|---|---|---|
| `external_id` | string | null | no | Max 191 characters. Pattern `^[A-Za-z0-9._:-]+$` |
| `phone` | string | null | no | International number, digits with optional +. Needed when there is no external_id. |
| `name` | string | null | no | Max 191 characters |
| `email` | string | null | no | Format email |
| `locale` | string | null | no | Max 16 characters |
| `timezone` | string | null | no | IANA, e.g. Africa/Accra. |
| `custom_fields` | object | no | Values for the business's fields; null clears one. |
| `tags` | array of strings | no | Replaces the contact's tags. |

### Request

```bash
curl --request PATCH \
  --url 'https://whatsapp.paaltech.org/api/v1/businesses/presec/contacts/2' \
  --header "Authorization: Bearer $PAALCHAT_TOKEN" \
  --header 'Accept: application/json' \
  --header 'Content-Type: application/json' \
  --data '{"name": "Ama Mensah-Boateng", "custom_fields": {"fee_balance": 0}}'
```

### Responses

- **200** - The updated contact.
- **401** - unauthenticated - missing, invalid, revoked or expired token

```json
{
  "error": {"code": "unauthenticated", "message": "A valid product token is required."}
}
```

- **403** - missing_ability, product_suspended or product_token_required

```json
{
  "error": {
    "code": "missing_ability",
    "message": "This token does not have the ability this request needs."
  }
}
```

- **404** - not_found - not yours, or does not exist

```json
{"error": {"code": "not_found", "message": "Business not found."}}
```

- **422** - validation_failed - fields are invalid; see errors.

```json
{
  "error": {
    "code": "validation_failed",
    "message": "The external id field format is invalid. (and 1 more error)"
  },
  "errors": {
    "external_id": ["The external id field format is invalid."],
    "name": ["The name field is required."]
  }
}
```

- **429** - rate_limited - over 300 requests/minute for this product

```json
{
  "error": {
    "code": "rate_limited",
    "message": "Too many requests. Slow down and retry after the Retry-After header."
  }
}
```