## Application line fields

`GET /v1/telephony-lines/fields`

Returns the field schema of an external application line: the type of each field, whether it is writable, its label and description. The schema is needed before [adding](./create.md) and [updating](./update.md) a line — it shows which fields are accepted and which are read-only.

## Examples

### curl — personal key

```bash
curl "https://vibecode.bitrix24.com/v1/telephony-lines/fields" \
  -H "X-Api-Key: YOUR_API_KEY"
```

### curl — OAuth application

```bash
curl "https://vibecode.bitrix24.com/v1/telephony-lines/fields" \
  -H "X-Api-Key: YOUR_APP_KEY" \
  -H "Authorization: Bearer USER_SESSION_TOKEN"
```

### JavaScript — personal key

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/telephony-lines/fields', {
  headers: {
    'X-Api-Key': 'YOUR_API_KEY',
  },
})

const { success, data } = await res.json()
console.log('Line fields:', Object.keys(data.fields))
```

### JavaScript — OAuth application

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/telephony-lines/fields', {
  headers: {
    'X-Api-Key': 'YOUR_APP_KEY',
    'Authorization': 'Bearer USER_SESSION_TOKEN',
  },
})

const { success, data } = await res.json()
```

## Response fields

| Field | Type | Description |
|------|-----|---------|
| `success` | boolean | Always `true` on success |
| `data.fields` | object | Line field schema. The key is the field name in camelCase, the value is its description |
| `data.fields.<name>.type` | string | Field value type: `string` or `boolean` |
| `data.fields.<name>.readonly` | boolean | `true` — the field is read-only, and a write is rejected with `400 READONLY_FIELD` |
| `data.fields.<name>.nullable` | boolean | Present on fields that may arrive with a `null` value |
| `data.fields.<name>.notReturned` | boolean | Present on fields that are declared in the schema but never come back in responses. Explicitly selecting such a name returns `UNKNOWN_SELECT_FIELD` |
| `data.fields.<name>.label` | string | Short field label |
| `data.fields.<name>.description` | string | Extended field description |
| `data.batch` | array | Line operations available in a batch call: `create`, `update`, `delete` |

The schema describes four fields:

| Field | Type | RO | Description |
|------|-----|----|---------|
| `number` | string | | External line number — also the line identifier in the update and delete paths |
| `name` | string \| null | | Line name shown in the interface. A line created without a name returns `null` |
| `crmAutoCreate` | boolean | | Whether to auto-create a lead or a contact for calls on this line |
| `serverName` | string | yes | Name of the telephony server the line is registered on. Not returned in responses, rejected on write |

## Response example

```json
{
  "success": true,
  "data": {
    "fields": {
      "number": {
        "type": "string",
        "readonly": false,
        "label": "Line number",
        "description": "External line number — the identifier of the telephony line."
      },
      "serverName": {
        "type": "string",
        "readonly": true,
        "notReturned": true,
        "label": "Server name",
        "description": "Name of the telephony server the line is registered on. Read-only: Bitrix24 neither stores nor returns it, so a write is rejected with 400 READONLY_FIELD instead of being silently dropped."
      },
      "name": {
        "type": "string",
        "readonly": false,
        "nullable": true,
        "label": "Line name",
        "description": "Human-readable name of the line shown in the interface. Nullable: a line created without a name returns null here."
      },
      "crmAutoCreate": {
        "type": "boolean",
        "readonly": false,
        "label": "Auto-create CRM entities",
        "description": "Whether CRM entities (lead/contact) are created automatically for calls on this line."
      }
    },
    "batch": ["create", "update", "delete"]
  }
}
```

## Error response example

401 — no key provided:

```json
{
  "success": false,
  "error": {
    "code": "MISSING_API_KEY",
    "message": "API key required. Pass via X-Api-Key header."
  }
}
```

## Errors

| HTTP | Code | Description |
|------|-----|---------|
| 401 | `MISSING_API_KEY` | The `X-Api-Key` header was not provided |
| 401 | `INVALID_API_KEY` | Invalid API key |
| 401 | `TOKEN_MISSING` | The key has no configured tokens |
| 401 | `KEY_INACTIVE` | The API key is inactive or revoked |
| 403 | `SCOPE_DENIED` | The key lacks the `telephony` scope |
| 429 | `RATE_LIMITED` | Request rate limit exceeded |

Full list of common API errors — [Errors](/docs/errors).

## Known specifics

**The schema is the same on every Bitrix24 account.** The response is assembled from the line description on the Vibecode side rather than requested from the account, so the set of fields and their types do not depend on a particular account's settings or on Bitrix24 availability. The response is cached, and the `X-Cache` header shows where it came from — the rules and the ways to bypass the cache are described in [Limits and optimization](/docs/optimization).

**`serverName` is declared but never comes back.** The field is in the schema, marked `notReturned`, and this is not a desync: it never comes back in the [list](./list.md), create, or update responses, and an attempt to write a value is rejected with `400 READONLY_FIELD` — the value is never silently lost. An explicit `select=serverName` returns an `UNKNOWN_SELECT_FIELD` warning, and the field is absent from the response. Treat it as a reference description, not as a data source.

**`batch` names the available batch operations.** The array lists the line operations accepted by a [batch call](/docs/batch): `create`, `update`, `delete`. Reads are not in this list — the list of lines is fetched by a separate call.

## See also

- [List application lines](./list.md)
- [Add a line](./create.md)
- [Update a line](./update.md)
- [Delete a line](./delete.md)
- [Limits and optimization](/docs/optimization)