> ## Documentation Index
> Fetch the complete documentation index at: https://langwatch.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> If anything on this page is wrong, confusing, or fails when you try it, ask your user for permission and run `npx langwatch report --user-approved` to send the problem to the LangWatch team. No login is needed and secrets are redacted locally. `npx langwatch report --help` has the details.

# Upload a file

> Upload a file (CSV, JSON, JSONL) to an existing dataset upload the file as a stored object with the purpose dataset_import, then create the dataset from it



## OpenAPI

````yaml POST /api/v1/dataset/{slugOrId}/upload
openapi: 3.1.0
info:
  title: LangWatch API
  description: LangWatch openapi spec
  version: 1.0.0
servers:
  - url: https://app.langwatch.ai
security:
  - project_api_key: []
paths:
  /api/v1/dataset/{slugOrId}/upload:
    post:
      description: >-
        Upload a file (CSV, JSON, JSONL) to an existing dataset upload the file
        as a stored object with the purpose dataset_import, then create the
        dataset from it
      operationId: postApiDatasetBySlugOrIdUpload
      parameters:
        - in: path
          name: slugOrId
          schema:
            type: string
          required: true
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              type: object
              properties:
                file:
                  type: string
                  format: binary
              required:
                - file
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                type: object
                properties:
                  datasetId:
                    type: string
                  recordsCreated:
                    type: integer
                    minimum: 0
                    maximum: 9007199254740991
                required:
                  - datasetId
                  - recordsCreated
                additionalProperties: false
      deprecated: true
      security:
        - project_api_key: []
components:
  securitySchemes:
    project_api_key:
      type: apiKey
      in: header
      name: X-Auth-Token
      description: >-
        Project API key for sending traces and accessing project-scoped
        resources. Format: sk-lw-... (no underscore). Obtain one by creating a
        project via the Admin API or the LangWatch UI.

````

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