> ## Documentation Index > Fetch the complete documentation index at: https://help.harmonica.chat/llms.txt > Use this file to discover all available pages before exploring further. # Generate structured session knowledge > Synthesises typed, structured knowledge from a session — decisions, action items, tensions, and atomic claims — each backed by the message IDs it was drawn from. When the session has grounding enabled, pre-extracted verbatim quotes are resolved to their source messages and woven in as provenance. The session must already have a summary (call `POST /sessions/{id}/summary` first). The generated knowledge is persisted on the session and returned. Requires **editor** access. Pro feature. This exposes the structured-knowledge **data layer** — there is no results-page UI for it yet. ## OpenAPI ````yaml /api-reference/openapi.yaml post /sessions/{id}/knowledge openapi: 3.1.0 info: title: Harmonica API version: 1.0.0 description: > REST API for the Harmonica structured deliberation platform. Provides access to sessions and their data, including creating, updating, and querying sessions, plus response submission for active sessions. contact: name: Harmonica url: https://harmonica.chat servers: - url: https://app.harmonica.chat/api/v1 description: Production - url: http://localhost:3000/api/v1 description: Local development security: - apiKey: [] paths: /sessions/{id}/knowledge: post: tags: - Sessions summary: Generate structured session knowledge description: > Synthesises typed, structured knowledge from a session — decisions, action items, tensions, and atomic claims — each backed by the message IDs it was drawn from. When the session has grounding enabled, pre-extracted verbatim quotes are resolved to their source messages and woven in as provenance. The session must already have a summary (call `POST /sessions/{id}/summary` first). The generated knowledge is persisted on the session and returned. Requires **editor** access. Pro feature. This exposes the structured-knowledge **data layer** — there is no results-page UI for it yet. operationId: generateSessionKnowledge parameters: - $ref: '#/components/parameters/sessionId' responses: '200': description: Generated (or skipped) session knowledge content: application/json: schema: type: object properties: status: type: string enum: - generated - skipped description: >- `generated` when knowledge was produced; `skipped` on a no-op. knowledge: description: The generated knowledge, or null when skipped. oneOf: - $ref: '#/components/schemas/SessionKnowledge' - type: 'null' reason: type: string description: Present when `status` is `skipped`. required: - status - knowledge '400': description: Session has no summary yet content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: validation_error message: Session has no summary yet — generate summary first '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' components: parameters: sessionId: name: id in: path required: true schema: type: string format: uuid description: Session ID schemas: SessionKnowledge: type: object description: | Structured, typed knowledge synthesised from a session — decisions, action items, tensions, and atomic claims — each carrying message-ID provenance. Generated after the session summary. Pro feature. properties: decisions: type: array items: type: object properties: label: type: string summary: type: string evidence: type: array description: Source message IDs backing this decision. items: type: string phase: type: string required: - label - summary - evidence actions: type: array items: type: object properties: description: type: string owner: type: string due: type: string evidence: type: array items: type: string required: - description - evidence tensions: type: array items: type: object properties: summary: type: string sides: type: array minItems: 2 items: type: string evidence: type: array items: type: string required: - summary - sides - evidence claims: type: array items: type: object properties: category: type: string enum: - decision - tension - action - open-question - observation - quote - minority-view text: type: string evidence: type: array items: type: string phase: type: string strength: type: number minimum: 0 maximum: 1 required: - category - text - evidence gaps: type: array description: Areas the session left unresolved (optional). items: type: string metadata: type: object properties: generatedAt: type: integer description: Unix epoch timestamp when the knowledge was generated. model: type: string version: type: integer enum: - 1 required: - generatedAt - model - version required: - decisions - actions - tensions - claims - metadata Error: type: object properties: error: type: object properties: code: type: string enum: - unauthorized - forbidden - not_found - validation_error - rate_limited - internal_error - unprocessable message: type: string required: - code - message required: - error responses: Unauthorized: description: Missing or invalid API key content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: unauthorized message: Invalid or missing API key Forbidden: description: Insufficient permissions content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: forbidden message: You don't have access to this session NotFound: description: Resource not found content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: not_found message: Session not found securitySchemes: apiKey: type: http scheme: bearer description: | API key authentication. Pass your key as a Bearer token. Keys use the format `hm_live_<32 hex chars>`. Generate keys from your Harmonica dashboard settings. ````