# October 28, 2026 

** October 28, 2026 Karbon API release adds read-only Segments endpoints (preview), lets you PATCH a work item's PrimaryStatus and SecondaryStatus, returns LastModifiedDateTime on work items, and supports filing deadline due and deadline dates on Work Schedules. **
---

## Segments (Preview)

This is a **preview**, available on request. Request access via the [issue form](/issues/). We don't expect breaking changes, but the shape may evolve based on feedback.

Three new read-only endpoints return your shared Contact Segments and the clients in them:

| Endpoint | Returns |
|---|---|
| `GET /v3/Segments` | Every shared Contact Segment on the account |
| `GET /v3/Segments/{SegmentKey}` | A single Segment, or a `404` if the key doesn't match a shared Contact Segment |
| `GET /v3/Segments/{SegmentKey}/Members` | A paged list of the Contacts and Organizations in the Segment |

```http
GET https://api.karbonhq.com/v3/Segments/4fGh7JkL2mNp/Members?$top=100
```

```json
{
  "@odata.count": 248,
  "@odata.nextLink": "https://api.karbonhq.com/v3/Segments/4fGh7JkL2mNp/Members?$skip=100",
  "value": [
    { "EntityKey": "7wPqXnT4mBjK", "EntityType": "Organization" },
    { "EntityKey": "RXq4mB32PXg", "EntityType": "Contact" }
  ]
}
```

Members are ordered by name and returned as a key and type only. Fetch full details from `GET /v3/Contacts/{ContactKey}` or `GET /v3/Organizations/{OrganizationKey}`. `$top` accepts up to `100`; follow `@odata.nextLink` for the next page. Private and Hidden clients are only included when your app has the matching `IncludePrivate`/`IncludeHidden` permission.

Personal (unshared) Segments aren't returned, and `GET /v3/Segments` doesn't support `$filter`, `$top` or `$skip`.

## Patch PrimaryStatus and SecondaryStatus on a Work Item

`PATCH /v3/WorkItems/{WorkItemKey}` now accepts `PrimaryStatus` and `SecondaryStatus`, so you can move a work item through its statuses without a full `PUT`:

```http
PATCH https://api.karbonhq.com/v3/WorkItems/{WorkItemKey}
```

```json
{
  "PrimaryStatus": "In Progress",
  "SecondaryStatus": "Send client requests"
}
```

- `PrimaryStatus` is required whenever `SecondaryStatus` is sent.
- Sending `PrimaryStatus` on its own clears the work item's `SecondaryStatus`.
- `SecondaryStatus` must belong to the `PrimaryStatus` and be enabled for the work item's `WorkType`. Valid values are listed under `WorkStatuses` in `GET /v3/TenantSettings`.

An invalid status returns a `400`. Unlike `PUT`, `PATCH` never silently drops a `SecondaryStatus` that doesn't apply to the work item's `WorkType`.

## LastModifiedDateTime on Work Items

`GET /v3/WorkItems` and `GET /v3/WorkItems/{WorkItemKey}` now return `LastModifiedDateTime`, the date and time the work item was last changed:

```json
{
  "WorkItemKey": "4jgPTtcXxwC2",
  "Title": "FY2026 Income Tax Return",
  "LastModifiedDateTime": "2026-10-27T22:14:05Z",
  ...
}
```

`LastModifiedDateTime` is read-only, and can't yet be used in `$filter` or `$orderby`.

## Filing Deadline Dates on Work Schedules

`POST` and `PUT` on `/v3/WorkSchedules` now accept `OnFilingDate` for both `ScheduleDueDateMethod` and `ScheduleDeadlineDateMethod`, setting the date from one of your account's filing deadlines. Each method takes two new properties:

| Property | Description |
|---|---|
| `ScheduleDueDateFilingDeadlineKey` / `ScheduleDeadlineDateFilingDeadlineKey` | The filing deadline to use. Keys are listed under `FilingDeadlines` in `GET /v3/TenantSettings`. |
| `ScheduleDueDateResolveType` / `ScheduleDeadlineDateResolveType` | `FilingDeadline` to use the filing deadline's date, or `FilingDeadlineExtension` to use its extension date. |

```http
POST https://api.karbonhq.com/v3/WorkSchedules
```

```json
{
  "CreatedFromWorkItemKey": "4jgPTtcXxwC2",
  "RecurrenceFrequency": "Year",
  "ScheduleStartDate": "2027-01-01T00:00:00Z",
  "ScheduleDueDateMethod": "OnFilingDate",
  "ScheduleDueDateFilingDeadlineKey": "2kTn7wQpXc4R",
  "ScheduleDueDateResolveType": "FilingDeadline",
  "ScheduleDeadlineDateMethod": "OnFilingDate",
  "ScheduleDeadlineDateFilingDeadlineKey": "2kTn7wQpXc4R",
  "ScheduleDeadlineDateResolveType": "FilingDeadlineExtension"
}
```

The key and resolve type are required together when the method is `OnFilingDate`, and can't be sent with any other method. On `PUT`, omitting the key on a schedule that already uses `OnFilingDate` keeps its existing filing deadline. `GET /v3/WorkSchedules/{WorkScheduleKey}` returns all four properties, `null` unless the matching method is `OnFilingDate`.

Companies House deadline methods are still not available through the API.

Refer to the [API documentation](https://karbonhq.github.io/karbon-api-reference/#post-/v3/WorkSchedules) for more information on work schedules.