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

# Upload Contacts CSV

> Get a presigned S3 URL to upload a contacts CSV for a campaign

Uploading contacts is a two-step process. First call this endpoint to get a presigned upload URL, then PUT your CSV directly to that URL.

```bash theme={null}
# Step 1: Get upload URL
curl -X POST https://your-asisso-instance/api/v1/s3/presigned-upload-url \
  -H "X-API-Key: dg_your_api_key"

# Response:
# { "upload_url": "https://...", "s3_key": "campaigns/..." }

# Step 2: Upload the CSV
curl -X PUT "https://presigned-url..." \
  -H "Content-Type: text/csv" \
  --data-binary @contacts.csv
```

Use the `s3_key` from the response as the `source_url` when [creating a campaign](/api-reference/campaigns/create).

### CSV format

The CSV must include a `phone_number` column. Any additional columns are passed as `initial_context` to each call, making them available as template variables in the workflow.

```csv theme={null}
phone_number,customer_name,plan
+14155550100,Jane Smith,premium
+14155550101,Bob Jones,basic
```


## OpenAPI

````yaml POST /api/v1/s3/presigned-upload-url
openapi: 3.1.0
info:
  title: Asisso API
  description: API for the Asisso app
  version: 1.0.0
servers:
  - url: https://app.asisso.com
    description: Production
  - url: http://localhost:8000
    description: Local development
security: []
paths:
  /api/v1/s3/presigned-upload-url:
    post:
      tags:
        - main
        - s3
      summary: Generate a presigned URL for direct CSV upload
      description: >-
        Generate a presigned PUT URL for direct CSV file upload to S3/MinIO.


        This endpoint enables browser-to-storage uploads without passing through
        the backend


        Access Control:

        * All authenticated users can upload CSV files scoped to their
        organization.

        * Files are stored with organization-scoped keys for multi-tenancy.


        Returns:

        * upload_url: Presigned URL (valid for 15 minutes) for PUT request

        * file_key: Unique storage key to use as source_id in campaign creation

        * expires_in: URL expiration time in seconds
      operationId: get_presigned_upload_url_api_v1_s3_presigned_upload_url_post
      parameters:
        - name: authorization
          in: header
          required: false
          schema:
            anyOf:
              - type: string
              - type: 'null'
            title: Authorization
        - name: X-API-Key
          in: header
          required: false
          schema:
            anyOf:
              - type: string
              - type: 'null'
            title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/PresignedUploadUrlRequest'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PresignedUploadUrlResponse'
        '404':
          description: Not found
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
components:
  schemas:
    PresignedUploadUrlRequest:
      properties:
        file_name:
          type: string
          pattern: .*\.csv$
          title: File Name
          description: CSV filename
        file_size:
          type: integer
          maximum: 10485760
          exclusiveMinimum: 0
          title: File Size
          description: File size in bytes (max 10MB)
        content_type:
          type: string
          title: Content Type
          description: File content type
          default: text/csv
      type: object
      required:
        - file_name
        - file_size
      title: PresignedUploadUrlRequest
    PresignedUploadUrlResponse:
      properties:
        upload_url:
          type: string
          title: Upload Url
        file_key:
          type: string
          title: File Key
        expires_in:
          type: integer
          title: Expires In
      type: object
      required:
        - upload_url
        - file_key
        - expires_in
      title: PresignedUploadUrlResponse
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
              - type: string
              - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
        input:
          title: Input
        ctx:
          type: object
          title: Context
      type: object
      required:
        - loc
        - msg
        - type
      title: ValidationError

````