> ## Documentation Index > Fetch the complete documentation index at: https://support.callin.io/llms.txt > Use this file to discover all available pages before exploring further. # Upload document file > Uploads a file (PDF, DOCX, TXT, etc.) and creates a new knowledge base document from its contents. ## OpenAPI ````yaml /openapi.json post /public/v1/knowledge-base/documents/file openapi: 3.0.3 info: title: Callin Public API version: 1.0.0 description: >- The Callin public API lets you programmatically build and manage AI voice agents, control their knowledge bases, and retrieve call logs and transcripts. All endpoints are versioned under /public/v1. servers: - url: https://api.callin.io/api description: API Endpoint security: [] tags: - name: Health description: Service availability check. No authentication required. - name: Identity description: Verify which account is associated with the current API key. - name: Agents description: Create, retrieve, and update AI voice agents. - name: Conversations description: List and inspect call logs, transcripts, and conversation details. - name: Knowledge Base description: Manage documents and groups that agents use during calls. paths: /public/v1/knowledge-base/documents/file: post: tags: - Knowledge Base summary: Upload document file description: >- Uploads a file (PDF, DOCX, TXT, etc.) and creates a new knowledge base document from its contents. requestBody: required: true content: multipart/form-data: schema: $ref: '#/components/schemas/CreateDocumentFromFileRequest' responses: '200': description: Document created content: application/json: schema: $ref: '#/components/schemas/SuccessDocumentCreateFromFileResponse' '400': description: Invalid request body content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' security: - ApiKeyHeader: [] - BearerAuth: [] components: schemas: CreateDocumentFromFileRequest: type: object description: >- Upload one or more files into a knowledge group (`multipart/form-data`). The group is created or matched by `groupName`. required: - groupName - files properties: groupName: type: string description: Name of the knowledge group to create or add these documents to. files: type: array minItems: 1 description: >- Files to upload. Each file must be **PDF** (`.pdf`), **Word** (`.docx`), or **TSX** (`.tsx`). **Maximum 5 MB** per file. items: type: string format: binary description: 'One file: PDF, DOCX, or TSX; max 5 MB.' SuccessDocumentCreateFromFileResponse: type: object properties: success: type: boolean example: true data: description: The details of the document created type: object properties: groupId: type: string description: The ID of the group created name: type: string description: The name of the group documents: type: array description: >- Created file documents. Each item uses nested `details` (`fileUrl`, `fileType`, `fileSize`); no `url` at the document root. items: $ref: '#/components/schemas/DocumentDetailsFile' metadata: type: object description: Knowledge-base storage usage in MB (no audit fields). properties: allowedMb: type: number description: The allowed size of the document in MB usedMb: type: number description: The used size of the document in MB usedMbAfter: type: number description: >- The used size of the document in MB after the document was created remainingMbAfter: type: number description: >- The remaining size of the document in MB after the document was created description: >- After uploading files: new or updated group, created documents, and storage usage (MB). ErrorResponse: type: object description: >- Returned for most client and validation errors. Read `error.message` and optional `error.fields` for details. properties: success: type: boolean example: false description: Always `false` for this shape. error: type: object description: Structured error payload from the API. properties: code: type: string description: Stable machine-oriented error code when provided. message: type: string description: Human-readable explanation suitable to show or log. status: type: integer description: HTTP status code echoed for convenience. fields: type: array description: >- Optional per-field validation issues (shape is endpoint-specific). items: type: object DocumentDetailsFile: type: object description: >- Uploaded file document. `details` holds storage URL, MIME type, and size; display name is `name`. additionalProperties: false properties: documentId: type: string description: The ID of the document. type: type: string enum: - file description: 'Discriminator: uploaded file document.' name: type: string description: Display name (often the original file name). details: $ref: '#/components/schemas/DocumentFileDetails' metadata: type: object description: Optional server metadata. properties: createdAt: type: string format: date-time description: When the document was created. createdBy: $ref: '#/components/schemas/MetaCreatedBy' DocumentFileDetails: type: object description: Type-specific payload when `type` is `file` (no source URL). additionalProperties: false properties: fileUrl: type: string description: Public URL of the stored file. fileType: type: string description: MIME type of the file (e.g. `application/pdf`, `text/plain`). fileSize: type: number description: File size in bytes. MetaCreatedBy: type: object properties: userId: type: string description: The ID of the user who created the item userEmail: type: string description: The email of the user who created the item securitySchemes: ApiKeyHeader: type: apiKey in: header name: x-api-key description: Send your Callin API key in the `x-api-key` header. BearerAuth: type: http scheme: bearer bearerFormat: API Key description: 'Same API key as a Bearer token: `Authorization: Bearer `.' ````