> ## 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. # Update Brand Fact > Updates one brand fact's text, source URL, or confidence. Only provided fields change; pass source_url: "" to clear the stored source. Changing the text creates a new fact (new id) and archives the current one; the new fact keeps the current review status and is the fact returned. Source URL and confidence edits update the fact in place and re-match the source to the internal link bank. Review status never changes through this endpoint. Requires a website-admin API key. Also available as the MCP tool `update_brand_fact`. ## OpenAPI ````yaml /api-reference/openapi.json patch /api/v1/knowledge-base/facts/{fact_id} 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/facts/{fact_id}: patch: tags: - Knowledge Base summary: Update Brand Fact description: >- Updates one brand fact's text, source URL, or confidence. Only provided fields change; pass source_url: "" to clear the stored source. Changing the text creates a new fact (new id) and archives the current one; the new fact keeps the current review status and is the fact returned. Source URL and confidence edits update the fact in place and re-match the source to the internal link bank. Review status never changes through this endpoint. Requires a website-admin API key. Also available as the MCP tool `update_brand_fact`. operationId: updateBrandFact parameters: - name: fact_id in: path required: true schema: type: string format: uuid description: The fact to update. requestBody: required: true content: application/json: schema: type: object properties: website_id: type: string format: uuid description: The website the fact belongs to. text: type: string minLength: 1 maxLength: 10000 description: >- New fact statement. Caps at 10000 characters, matching the in-app edit dialog (add_brand_facts caps new facts at 2000). source_url: type: string maxLength: 2048 description: >- New source URL. An empty string clears the stored source URL. confidence: type: string enum: - high - medium - low description: New confidence level. required: - website_id responses: '200': description: The updated fact plus a pre-update snapshot of the editable fields content: application/json: schema: type: object properties: fact: $ref: '#/components/schemas/BrandFact' before: type: object description: Values of the editable fields before this update. properties: text: type: string source_url: type: - string - 'null' confidence: type: - string - 'null' enum: - high - medium - low - null required: - text - source_url - confidence required: - fact - before '400': description: Bad request - Invalid parameters content: application/json: schema: $ref: '#/components/schemas/Error' examples: missing_website_id: value: error: website_id is required blank_text: value: error: text must not be blank unsafe_source_url: value: error: source_url is not a valid URL '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 - No fact with this id on the website content: application/json: schema: $ref: '#/components/schemas/Error' examples: fact_not_found: value: error: Fact not found '409': description: >- Conflict - The fact cannot be replaced: it was captured from an AI response, is a hidden duplicate, is rejected, or another edit archived it first (fetch the fact again and retry against the live one). A text change on a fact that has already been replaced returns 404, since the addressed fact is archived. content: application/json: schema: $ref: '#/components/schemas/Error' examples: identical_fact: value: error: An identical fact already exists security: - apiKey: [] components: schemas: BrandFact: type: object properties: id: type: string format: uuid text: type: string description: The fact statement. status: type: string enum: - approved - pending - rejected description: Review status of the fact. confidence: type: - string - 'null' enum: - high - medium - low - null description: Confidence level assigned during ingestion, or null when unrated. source_url: type: - string - 'null' description: URL the fact was extracted from, stored without protocol. source_quote: type: - string - 'null' description: Verbatim quote from the source backing the fact. source_type: type: string enum: - research - response - upload - content_hub description: How the fact entered the Knowledge Base. pillar: $ref: '#/components/schemas/BrandFactPillar' created_at: type: string description: ISO 8601 timestamp of when the fact was added. required: - id - text - status - confidence - source_url - source_quote - source_type - pillar - created_at Error: type: object description: Error response object required: - error properties: error: type: string description: Error message describing what went wrong example: Unauthorized BrandFactPillar: type: - object - 'null' description: >- The published pillar the fact is filed under, or null when the fact is unfiled. properties: id: type: string format: uuid name: type: string required: - id - name 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). ````