---
title: "Append Entries to a Custom List Version"
method: POST
path: "/custom-lists/{customListToken}/append"
tags: ["Custom Lists"]
---

# Append Entries to a Custom List Version

`POST /custom-lists/{customListToken}/append`

Append entries to the latest minor version of a major version <b>in place</b>, without creating a new version. The entries are added to the existing version and the version string is unchanged. This differs from <code>POST /custom-lists/{customListToken}/versions</code> with an <code>added</code> body, which creates a new minor version. Appends always target the latest minor version of the specified major version.

## Request body

- object
  - `base_version` object, required — The major version to append entries to. Entries are always appended to the latest minor version of this major version, in place, without creating a new version. Optionally provide 'minor_version' to assert the target; it must match the latest minor version of the major version or the request is rejected.
    - `major_version` integer, required
    - `minor_version` integer
  - `added` object[], required — Array of data entries to append to the latest minor version. Must contain at least one entry.

## Response `200`

Successfully appended entries to the custom list version

- object
  - `custom_list_token` string
  - `version` string — The version string that entries were appended to (unchanged).

## Other responses

- `400` — Bad request - Invalid Input Data, or the target version is not the latest minor version of the major version
- `403` — Forbidden - Insufficient Permissions
- `404` — Custom List or Major Version Not Found
- `409` — Conflict - An append is already in progress for this version

---

[API](https://skmtc.dev/alloy/apis/alloy-api.md) · [All operations](https://skmtc.dev/alloy/apis/alloy-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/alloy/alloy-api/revisions/405799de4d2a/schema)