> ## Documentation Index > Fetch the complete documentation index at: https://developers.lighton.ai/llms.txt > Use this file to discover all available pages before exploring further. # Remove a tag from a file > Remove a specific tag from a file. **Behavior:** - Removes the specified tag from the document - Works for both manually assigned and auto-assigned tags - Idempotent: returns 204 even if tag was not on the document **Validation:** - Returns 403 if user doesn't have permission to edit the document - Returns 404 if document doesn't exist - Returns 404 if tag doesn't exist or doesn't belong to user's company ## OpenAPI ````yaml /api-reference/api-console.yaml delete /api/v3/files/{id}/tags/{tag_id} openapi: 3.1.0 info: title: LightOn API version: 3.15.0 (v1) description: >- LightOn gives you an API to search, parse, and ingest documents at scale. Build knowledge-retrieval pipelines without managing vector databases or OCR models. servers: - url: https://api.lighton.ai security: [] tags: - name: Ask description: >- Retrieval-augmented generation: search your indexed corpus and generate an LLM answer grounded in the retrieved passages. Supports streaming (SSE) and synchronous modes. - name: Search description: >- Hybrid vector + text retrieval over your indexed corpus. Returns ranked passages with provenance (file, page range, workspace). Optional reranking and vision mode. - name: Files description: Upload, list, fetch, and delete documents indexed in your workspaces. - name: Facets description: >- Organise documents with hierarchical content types and custom attributes per file. Start from starter templates or build your own classification schema from scratch. - name: Tags description: >- Manage flat, company-wide labels used to scope search and group content across workspaces. - name: Workspaces description: >- Create and manage workspaces — the access-controlled containers your documents live in. - name: Parse description: >- Convert documents into structured Markdown — PDFs, images, Office files, and HTML. Synchronous endpoint capped at 20 MB / 15 pages. - name: Extract description: >- Pull typed fields out of documents using a JSON Schema you provide. Sync mode for small documents (≤20 MB / 15 pages); async mode for larger jobs (≤100 MB / 1000 pages) with polling on a job ID. - name: API Keys description: >- Provision and revoke API keys used to authenticate against the Console API. - name: Budget description: >- Manage your organization's monthly spend budget and alert thresholds. Set a hard cap that blocks API requests when reached, and configure email notifications at custom spend percentages. paths: /api/v3/files/{id}/tags/{tag_id}: delete: tags: - Files summary: Remove a tag from a file description: | Remove a specific tag from a file. **Behavior:** - Removes the specified tag from the document - Works for both manually assigned and auto-assigned tags - Idempotent: returns 204 even if tag was not on the document **Validation:** - Returns 403 if user doesn't have permission to edit the document - Returns 404 if document doesn't exist - Returns 404 if tag doesn't exist or doesn't belong to user's company operationId: api_v3_files_tags_destroy parameters: - in: path name: id schema: type: integer required: true - in: path name: tag_id schema: type: integer required: true responses: '204': description: Tag removed successfully (or was already not on the file) '401': content: application/json: schema: $ref: '#/components/schemas/APIV3ErrorResponse' examples: Unauthorized: value: id: null code: 401 error: unauthorized detail: >- Authentication credentials were not provided or are invalid. doc_url: https://developers.lighton.ai/errors#unauthorized description: Authentication credentials were not provided or are invalid '403': content: application/json: schema: $ref: '#/components/schemas/APIV3ErrorResponse' examples: Forbidden: value: id: null code: 403 error: insufficient_permissions detail: You do not have permission to perform this action. doc_url: >- https://developers.lighton.ai/errors#insufficient_permissions description: Insufficient permissions '404': content: application/json: schema: $ref: '#/components/schemas/APIV3ErrorResponse' examples: NotFound: value: id: null code: 404 error: not_found detail: The requested resource was not found. doc_url: https://developers.lighton.ai/errors#not_found summary: Not Found description: The requested resource was not found '503': description: >- API is under maintenance. Check `GET /api/v3/system/status` for active periods and retry. content: application/json: schema: $ref: '#/components/schemas/ServiceMaintenance503' security: - bearerAuth: [] components: schemas: APIV3ErrorResponse: type: object properties: id: type: - string - 'null' description: >- Job/resource id when one already exists (useful for async error diagnosis); null otherwise. code: type: integer description: HTTP status code error: type: string description: Error code used by the UI as a translation key detail: type: string description: Human-readable error message for developers doc_url: type: string description: Link to the error-code documentation page required: - code - detail - doc_url - error - id ServiceMaintenance503: type: object description: >- Returned by the maintenance middleware when the requested endpoint is blocked. required: - detail - error - mode properties: detail: type: string example: System is under maintenance. error: type: string example: service_maintenance mode: type: string enum: - full_shutdown - warning_banner description: >- `full_shutdown` blocks all traffic; `warning_banner` also blocks and shows a dismissible toast. reason: type: string description: Operator-supplied maintenance reason, if any. started_at: type: string format: date-time endpoint_category_names: type: array items: type: string description: >- Non-empty only for category-scoped periods. Empty means all endpoints are affected. securitySchemes: bearerAuth: type: http scheme: bearer description: >- Bearer authentication header of the form `Bearer `, where `` is your auth token. ````