> ## Documentation Index > Fetch the complete documentation index at: https://docs.athenahq.ai/llms.txt > Use this file to discover all available pages before exploring further. # Merge Pillars > 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`. ## OpenAPI ````yaml /api-reference/openapi.json post /api/v1/knowledge-base/pillars/merge openapi: 3.1.0 info: title: AthenaHQ API description: >- AthenaHQ API provides programmatic access to manage your websites and prompts for AI-powered content optimization. version: 1.0.0 contact: email: support@athenahq.ai servers: - url: https://api.athenahq.ai description: Production server security: - apiKey: [] tags: - name: Basics description: Core API operations for managing websites and prompts - name: Metrics description: Metrics and analytics endpoints for tracking AI visibility - name: Billing description: Billing and credits endpoints for managing usage - name: Team Management description: Endpoints for managing team members and invitations - name: Groups description: Endpoints for managing groups of websites - name: Content description: >- Endpoints for accessing Content Hub data — tabs, tracked URLs, and per-URL prompt breakdowns. - name: Pitch Workspace description: >- Endpoints for accessing pitch workspace reports — org-scoped pitch runs with competitors, prompts, attributes, and aggregate metrics. - name: Knowledge Base description: >- Endpoints for reading the brand Knowledge Base — approved brand facts and the pillars that organize them. paths: /api/v1/knowledge-base/pillars/merge: post: tags: - Knowledge Base summary: Merge Pillars description: >- 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`. operationId: mergePillars requestBody: required: true content: application/json: schema: type: object properties: website_id: type: string format: uuid description: The website whose pillars to merge. target_pillar_id: type: string format: uuid description: >- The published pillar that survives and receives the sources' facts. source_pillar_ids: type: array minItems: 1 maxItems: 20 items: type: string format: uuid description: Pillars to fold into the target. Deleted after the merge. required: - website_id - target_pillar_id - source_pillar_ids responses: '200': description: Merge report content: application/json: schema: type: object properties: success: type: boolean enum: - true moved_fact_count: type: integer description: Facts re-filed from the sources onto the target. merged_pillars: type: array items: type: object properties: id: type: string name: type: string required: - id - name description: >- The deleted source pillars, in request order. A deleted pillar cannot be re-fetched, so this is the caller's record. pillar: type: object description: The surviving target pillar. properties: id: type: string name: type: string required: - id - name required: - success - moved_fact_count - merged_pillars - pillar '400': description: >- Bad request - Invalid parameters, no source other than the target, or the target pillar is not published content: application/json: schema: $ref: '#/components/schemas/Error' examples: unpublished_target: value: error: pillars can only be merged into a published pillar source_is_target: value: error: source_pillar_ids must not include the target '401': description: Unauthorized - Invalid or missing API key content: application/json: schema: $ref: '#/components/schemas/Error' '403': description: >- Forbidden - No admin access to this website, or the Knowledge Base is not enabled for the organization content: application/json: schema: $ref: '#/components/schemas/Error' examples: unauthorized_website: value: error: Unauthorized access to this website kb_not_enabled: value: error: Knowledge Base is not enabled for this organization '404': description: >- Not found - The target or one of the sources does not exist on the website content: application/json: schema: $ref: '#/components/schemas/Error' examples: target_not_found: value: error: Target pillar not found sources_not_found: value: error: One or more source pillars were not found security: - apiKey: [] components: schemas: Error: type: object description: Error response object required: - error properties: error: type: string description: Error message describing what went wrong example: Unauthorized securitySchemes: apiKey: type: apiKey in: header name: x-api-key description: >- API key for authentication. You can create one [here](https://app.athenahq.ai/organization?tab=api). ````