> ## Documentation Index > Fetch the complete documentation index at: https://devs.izap.ai/llms.txt > Use this file to discover all available pages before exploring further. # Upload an attachment > Uploads a file to be attached to a message on this conversation, and returns the stored reference to pass when sending that message. ## OpenAPI ````yaml /api-reference/openapi.json post /api/v1/chats/{chat_id}/upload openapi: 3.1.0 info: contact: email: suporte@izap.ai name: iZap API Support description: Public REST API for the iZap WhatsApp business messaging platform. license: name: MIT url: https://opensource.org/licenses/MIT title: iZap API version: v1 servers: - description: Production url: https://api.izap.ai - description: Staging url: https://api-staging.izap.ai security: [] tags: - description: >- Personal access tokens for calling this API, plus introspection of the token presented on a request. name: api-tokens - description: >- Create a business, read and update its profile, and manage its opening hours. name: businesses - description: >- Reusable images belonging to the caller's business, referenced when composing messages. name: business-library - description: Product catalog menus a business publishes to its customers. name: menus - description: >- Provision and inspect the WhatsApp Cloud API numbers attached to a business: registration, WABA details, per-number assistant binding and catalog sends. name: whatsapp-cloud - description: >- Conversation lifecycle — list, create and delete chats, and control read, snooze, status and AI pause state. name: chats - description: >- Read a conversation's messages, send free-form or template replies, and upload attachments. name: messages - description: >- Manage WhatsApp message templates: draft them locally, submit them to Meta for review and sync approval status back. name: whatsapp-templates - description: >- Bulk template sends. A transmission is previewed into a draft, then confirmed or cancelled — confirming dispatches to real recipients. name: transmissions - description: >- Register URLs that receive signed event deliveries when something happens in a business, rotate their signing secrets, and replay an individual delivery. name: webhooks - description: >- Server-rendered order visualisation page for a business slug, behind HTTP Basic auth. name: orders paths: /api/v1/chats/{chat_id}/upload: post: tags: - messages summary: Upload an attachment description: >- Uploads a file to be attached to a message on this conversation, and returns the stored reference to pass when sending that message. operationId: uploadChatAttachment parameters: - in: path name: chat_id required: true schema: format: uuid title: Chat Id type: string requestBody: content: multipart/form-data: schema: $ref: >- #/components/schemas/Body_upload_files_api_v1_chats__chat_id__upload_post required: true responses: '200': content: application/json: schema: $ref: '#/components/schemas/FileUploadResponse' description: Successful Response '401': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: Missing or invalid credentials. '403': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: The credential is valid but not authorized for this action. '404': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: The resource, or the business named in the request, does not exist. '422': content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' description: Validation Error '429': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: >- Too many uploads for this user or chat in the current rate-limit window. default: content: application/json: schema: $ref: '#/components/schemas/ApiError' description: Unexpected error. security: - bearerAuth: [] components: schemas: Body_upload_files_api_v1_chats__chat_id__upload_post: properties: files: items: contentMediaType: application/octet-stream type: string title: Files type: array required: - files title: Body_upload_files_api_v1_chats__chat_id__upload_post type: object FileUploadResponse: description: Response for file upload properties: files: items: $ref: '#/components/schemas/UploadedFile' title: Files type: array required: - files title: FileUploadResponse type: object ApiError: description: >- The response body of a handled API error. ``detail`` is either a plain string (FastAPI's default for an ``HTTPException`` raised with a string, and for the ``default`` fastapi-users messages like ``"Not authenticated"``) or the structured :class:`ApiErrorDetail` object described above. ``code`` is present only on the top-level shape ``aizap.core.exceptions.AppException`` produces for its own 5xx responses (``"INTERNAL_ERROR"`` / ``"DB_ERROR"``); it does not duplicate the ``code`` nested inside a structured ``detail``. properties: code: anyOf: - type: string - type: 'null' default: null title: Code detail: anyOf: - type: string - $ref: '#/components/schemas/ApiErrorDetail' title: Detail required: - detail title: ApiError type: object HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' title: Detail type: array title: HTTPValidationError type: object UploadedFile: description: >- Schema for uploaded file metadata. Files can be stored in either S3 (object storage) or local filesystem, depending on the storage backend configuration. The URL format depends on the storage backend: - Local filesystem: `/uploads/chats/{chat_id}/{filename}` - S3: Presigned URL or direct bucket URL (format depends on S3 configuration) properties: file_size: title: File Size type: integer file_type: title: File Type type: string filename: title: Filename type: string id: format: uuid title: Id type: string url: title: Url type: string required: - id - filename - file_type - file_size - url title: UploadedFile type: object ApiErrorDetail: additionalProperties: true description: |- The structured ``detail`` object some error responses carry. Several handlers (the REST API plan gate, the free-tier limits, the webhooks entitlement gate, the closed customer-service window) raise ``HTTPException(detail={"code": ..., "message": ..., ...})`` — a fixed ``code``/``message`` pair plus extra fields specific to that error. ``extra="allow"`` keeps those fields in the documented shape instead of dropping them. properties: code: title: Code type: string message: title: Message type: string required: - code - message title: ApiErrorDetail type: object ValidationError: properties: ctx: title: Context type: object input: title: Input loc: items: anyOf: - type: string - type: integer title: Location type: array msg: title: Message type: string type: title: Error Type type: string required: - loc - msg - type title: ValidationError type: object securitySchemes: bearerAuth: description: >- Personal access token (izap_pat_…) sent as Authorization: Bearer ; dashboard session JWTs are also accepted. scheme: bearer type: http ````