---
title: "Merge Pillars"
method: POST
path: "/api/v1/knowledge-base/pillars/merge"
tags: ["Knowledge Base"]
---

# Merge Pillars

`POST /api/v1/knowledge-base/pillars/merge`

## Request

- Base URL: `https://api.athenahq.ai`
- URL: `https://api.athenahq.ai/api/v1/knowledge-base/pillars/merge`
- Auth: API key in header `x-api-key`

Merges 1-20 source pillars into a published target pillar: every fact on the sources (any review status) re-files onto the target, page links carry over keeping the stronger signal, and the source pillars are then deleted. The target must be a published pillar and must not appear among the sources. Unlike the other Knowledge Base writes, retries are strict: missing source ids are rejected rather than skipped, so re-read the pillars before retrying a failed merge. Requires a website-admin API key. Also available as the MCP tool `merge_pillars`.

## Request body

- object
  - `website_id` string, uuid, required: The website whose pillars to merge.
  - `target_pillar_id` string, uuid, required: The published pillar that survives and receives the sources' facts.
  - `source_pillar_ids` string[], required: Pillars to fold into the target. Deleted after the merge.

## Response `200`

Merge report

- object
  - `success` true, required
  - `moved_fact_count` integer, required: Facts re-filed from the sources onto the target.
  - `merged_pillars` object[], required: The deleted source pillars, in request order. A deleted pillar cannot be re-fetched, so this is the caller's record.
    - `id` string, required
    - `name` string, required
  - `pillar` object, required: The surviving target pillar.
    - `id` string, required
    - `name` string, required

## Other responses

- `400`: Bad request - Invalid parameters, no source other than the target, or the target pillar is not published
- `401`: Unauthorized - Invalid or missing API key
- `403`: Forbidden - No admin access to this website, or the Knowledge Base is not enabled for the organization
- `404`: Not found - The target or one of the sources does not exist on the website

## Changes

- **2026-11-03** `2d1d86d5e067`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/athenahq/apis/athenahq-api/changes/api/v1/knowledge-base/pillars/merge/post.md)

---

[API](https://skmtc.dev/athenahq/apis/athenahq-api.md) - [All operations](https://skmtc.dev/athenahq/apis/athenahq-api/llms.txt) - [OpenAPI document](https://skmtc.dev/athenahq/apis/athenahq-api/revisions/6cf9ca58edf6?raw)