# POST /api/v1/ledgers/merge

> Merge ledgers

- **Tag:** ledgers
- **Operation ID:** `merge_ledgers`

## Description

Merge one or more source ledgers into a target ledger, reassigning all transactions and journal entries.

## Authentication

Bearer token in `Authorization` header.
Required header: `x-business-id: <business uuid>`.

## Request body

Schema: `LedgerMergeRequest`

- `source_ledger_ids` (array · string · required) — One or more ledger UUIDs to merge FROM (will be archived after merge).
- `target_ledger_id` (string · required) — The ledger UUID to merge INTO (receives all reassigned data).
- `new_name` (string) — Optional new name for the target ledger after merge.
- `confirmation` (string) — Required when merging system ledgers into another system ledger: must be the literal string 'MERGE'.

## Example request

```json
{
  "new_name": "Software & Subscriptions",
  "source_ledger_ids": [
    "0192a4f0-1b2c-7d3e-8f4a-5b6c7d8e9f12"
  ],
  "target_ledger_id": "0192a4f0-1b2c-7d3e-8f4a-5b6c7d8e9f11"
}
```

## Responses

### 201 — Successful Response

Schema: `SuccessEnvelope_LedgerMergeResponse_`

- `success` (boolean)
- `message` (string)
- `code` (string)
- `data` (LedgerMergeResponse)

### 400 — Bad Request - Invalid input

Schema: `ErrorResponse`

- `error` (string · required) — Error category: `validation_error`, `unauthorized`, `forbidden`, `not_found`, `conflict`, `rate_limited`, `server_error`, or `service_unavailable`.
- `message` (string · required) — Human-readable explanation, safe to show to end users.
- `code` (string · required) — Stable machine-readable code in `CATEGORY_NNN` form (e.g. `NOT_FOUND_006`, `AUTH_010`, `GEN_002`).
- `request_id` (string) — Correlation id for support requests. Echoes the `x-request-id` request header when one was supplied.
- `errors` (object) — Field-level validation messages keyed by field name. Present on 400/422 validation failures only.

### 401 — Unauthorized - Missing or expired token, an MCP OAuth token used against the REST API, or no access to this business

Schema: `ErrorResponse`

- `error` (string · required) — Error category: `validation_error`, `unauthorized`, `forbidden`, `not_found`, `conflict`, `rate_limited`, `server_error`, or `service_unavailable`.
- `message` (string · required) — Human-readable explanation, safe to show to end users.
- `code` (string · required) — Stable machine-readable code in `CATEGORY_NNN` form (e.g. `NOT_FOUND_006`, `AUTH_010`, `GEN_002`).
- `request_id` (string) — Correlation id for support requests. Echoes the `x-request-id` request header when one was supplied.
- `errors` (object) — Field-level validation messages keyed by field name. Present on 400/422 validation failures only.

### 403 — Forbidden - Insufficient permissions

Schema: `ErrorResponse`

- `error` (string · required) — Error category: `validation_error`, `unauthorized`, `forbidden`, `not_found`, `conflict`, `rate_limited`, `server_error`, or `service_unavailable`.
- `message` (string · required) — Human-readable explanation, safe to show to end users.
- `code` (string · required) — Stable machine-readable code in `CATEGORY_NNN` form (e.g. `NOT_FOUND_006`, `AUTH_010`, `GEN_002`).
- `request_id` (string) — Correlation id for support requests. Echoes the `x-request-id` request header when one was supplied.
- `errors` (object) — Field-level validation messages keyed by field name. Present on 400/422 validation failures only.

### 404 — Not Found - Resource does not exist

Schema: `ErrorResponse`

- `error` (string · required) — Error category: `validation_error`, `unauthorized`, `forbidden`, `not_found`, `conflict`, `rate_limited`, `server_error`, or `service_unavailable`.
- `message` (string · required) — Human-readable explanation, safe to show to end users.
- `code` (string · required) — Stable machine-readable code in `CATEGORY_NNN` form (e.g. `NOT_FOUND_006`, `AUTH_010`, `GEN_002`).
- `request_id` (string) — Correlation id for support requests. Echoes the `x-request-id` request header when one was supplied.
- `errors` (object) — Field-level validation messages keyed by field name. Present on 400/422 validation failures only.

### 409 — Conflict - Resource already exists or is in an incompatible state

Schema: `ErrorResponse`

- `error` (string · required) — Error category: `validation_error`, `unauthorized`, `forbidden`, `not_found`, `conflict`, `rate_limited`, `server_error`, or `service_unavailable`.
- `message` (string · required) — Human-readable explanation, safe to show to end users.
- `code` (string · required) — Stable machine-readable code in `CATEGORY_NNN` form (e.g. `NOT_FOUND_006`, `AUTH_010`, `GEN_002`).
- `request_id` (string) — Correlation id for support requests. Echoes the `x-request-id` request header when one was supplied.
- `errors` (object) — Field-level validation messages keyed by field name. Present on 400/422 validation failures only.

### 422 — Validation Error

Schema: `ErrorResponse`

- `error` (string · required) — Error category: `validation_error`, `unauthorized`, `forbidden`, `not_found`, `conflict`, `rate_limited`, `server_error`, or `service_unavailable`.
- `message` (string · required) — Human-readable explanation, safe to show to end users.
- `code` (string · required) — Stable machine-readable code in `CATEGORY_NNN` form (e.g. `NOT_FOUND_006`, `AUTH_010`, `GEN_002`).
- `request_id` (string) — Correlation id for support requests. Echoes the `x-request-id` request header when one was supplied.
- `errors` (object) — Field-level validation messages keyed by field name. Present on 400/422 validation failures only.

## Code samples

### cURL

```bash
curl -X POST 'https://api.ondayzero.com/api/v1/ledgers/merge' \
  -H 'Authorization: Bearer dz_your_token' \
  -H 'x-business-id: YOUR_BUSINESS_ID' \
  -H 'Content-Type: application/json' \
  -d '{
  "new_name": "Software & Subscriptions",
  "source_ledger_ids": [
    "0192a4f0-1b2c-7d3e-8f4a-5b6c7d8e9f12"
  ],
  "target_ledger_id": "0192a4f0-1b2c-7d3e-8f4a-5b6c7d8e9f11"
}'
```

### JavaScript

```javascript
const response = await fetch('https://api.ondayzero.com/api/v1/ledgers/merge', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer dz_your_token',
    'x-business-id': 'YOUR_BUSINESS_ID',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
  "new_name": "Software & Subscriptions",
  "source_ledger_ids": [
    "0192a4f0-1b2c-7d3e-8f4a-5b6c7d8e9f12"
  ],
  "target_ledger_id": "0192a4f0-1b2c-7d3e-8f4a-5b6c7d8e9f11"
}),
});
const data = await response.json();
```

### Python

```python
import httpx

headers = {
    "Authorization": "Bearer dz_your_token",
    "x-business-id": "YOUR_BUSINESS_ID",
}

payload = {'new_name': 'Software & Subscriptions',
 'source_ledger_ids': ['0192a4f0-1b2c-7d3e-8f4a-5b6c7d8e9f12'],
 'target_ledger_id': '0192a4f0-1b2c-7d3e-8f4a-5b6c7d8e9f11'}

response = httpx.post("https://api.ondayzero.com/api/v1/ledgers/merge", headers=headers, json=payload)
data = response.json()
```

## See also

- HTML version: https://www.ondayzero.com/docs/reference/ledgers/merge-ledgers
- OpenAPI slice: https://www.ondayzero.com/docs/reference/ledgers/merge-ledgers/openapi.json
- Other endpoints in **ledgers**: https://www.ondayzero.com/docs/reference/ledgers (markdown bundle: https://www.ondayzero.com/docs/reference/ledgers.md, OpenAPI: https://www.ondayzero.com/docs/reference/ledgers/openapi.json)
- Endpoint catalog: https://www.ondayzero.com/docs/reference/index.md