API Documentation

Overview

The SendFiles.Online API allows you to programmatically create file transfers, upload files, and manage your transfers. All API access requires a Business or Enterprise plan.

Base URL: https://sendfiles.online/api/v1/

All requests must be made over HTTPS. The API accepts JSON request bodies and returns JSON responses.

Authentication

Authenticate using your API key in the Authorization header:

Authorization: Bearer YOUR_API_KEY

Get your API key from your account dashboard. Keep your API key secret - don't share it or commit it to version control.

Security: Never expose your API key in client-side code. Make API calls from your server.

Create Transfer

Create a new transfer to get an upload URL.

POST /api/v1/transfers/

Request Body

Parameter	Type	Description
message	string	Optional message for recipients
password	string	Optional password protection
expires_days	integer	Days until expiration (default: plan limit)
notify_email	string	Email to notify on download

Example Request

curl -X POST https://sendfiles.online/api/v1/transfers/ \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"message": "Project files", "password": "secret123"}'
                

Response

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "short_id": "abc12345",
  "status": "uploading",
  "upload_url": "https://sendfiles.online/api/v1/transfers/550e8400.../upload/",
  "created_at": "2026-02-05T12:00:00Z",
  "expires_at": "2026-05-06T12:00:00Z"
}
                

Upload File

Upload a file to an existing transfer. Use multipart/form-data.

POST /api/v1/transfers/{id}/upload/

Request Body (multipart/form-data)

Parameter	Type	Description
file *	file	The file to upload

Example Request

curl -X POST https://sendfiles.online/api/v1/transfers/550e8400.../upload/ \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -F "file=@/path/to/document.pdf"
                

Response

{
  "id": "660f9500-f30c-52e5-b827-557766551111",
  "name": "document.pdf",
  "size": 1048576,
  "mime_type": "application/pdf"
}
                

Upload multiple files by making multiple requests to this endpoint.

Finalize Transfer

Finalize a transfer after uploading all files. This generates the download link.

POST /api/v1/transfers/{id}/finalize/

Example Request

curl -X POST https://sendfiles.online/api/v1/transfers/550e8400.../finalize/ \
  -H "Authorization: Bearer YOUR_API_KEY"
                

Response

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "short_id": "abc12345",
  "status": "ready",
  "download_url": "https://sendfiles.online/d/abc12345/",
  "files": [
    {"name": "document.pdf", "size": 1048576}
  ],
  "total_size": 1048576,
  "download_count": 0,
  "expires_at": "2026-05-06T12:00:00Z"
}
                

Get Transfer

Get details about a specific transfer.

GET /api/v1/transfers/{id}/

Example Request

curl https://sendfiles.online/api/v1/transfers/550e8400.../ \
  -H "Authorization: Bearer YOUR_API_KEY"
                

Response

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "short_id": "abc12345",
  "status": "ready",
  "download_url": "https://sendfiles.online/d/abc12345/",
  "files": [...],
  "total_size": 1048576,
  "download_count": 5,
  "created_at": "2026-02-05T12:00:00Z",
  "expires_at": "2026-05-06T12:00:00Z"
}
                

List Transfers

List all your transfers with pagination.

GET /api/v1/transfers/

Query Parameters

Parameter	Type	Description
page	integer	Page number (default: 1)
per_page	integer	Items per page (default: 20, max: 100)
status	string	Filter by status: uploading, ready, expired

Response

{
  "transfers": [...],
  "total": 42,
  "page": 1,
  "per_page": 20,
  "pages": 3
}
                

Delete Transfer

Delete a transfer and all its files.

DELETE /api/v1/transfers/{id}/

Example Request

curl -X DELETE https://sendfiles.online/api/v1/transfers/550e8400.../ \
  -H "Authorization: Bearer YOUR_API_KEY"
                

Response

{
  "success": true,
  "message": "Transfer deleted"
}
                

Webhooks

Receive notifications when events occur. Configure webhooks in your account settings.

Events

Event	Description
`transfer.ready`	Transfer finalized and ready for download
`transfer.downloaded`	Someone downloaded the transfer
`transfer.expired`	Transfer has expired

Webhook Payload

{
  "event": "transfer.downloaded",
  "timestamp": "2026-02-05T14:30:00Z",
  "data": {
    "transfer_id": "550e8400...",
    "short_id": "abc12345",
    "download_count": 1,
    "downloader_ip": "203.0.113.1"
  }
}
                

Error Handling

The API uses standard HTTP status codes. Errors include a JSON body with details.

Code	Description
`400`	Bad Request - Invalid parameters
`401`	Unauthorized - Invalid or missing API key
`403`	Forbidden - Insufficient permissions
`404`	Not Found - Transfer doesn't exist
`413`	Payload Too Large - File exceeds plan limit
`429`	Too Many Requests - Rate limited
`500`	Server Error - Something went wrong

Error Response

{
  "error": "invalid_parameter",
  "message": "expires_days must be between 1 and 90",
  "field": "expires_days"
}
                

Rate Limits

API requests are rate limited per API key:

Plan	Requests/minute	Requests/day
Business	60	10,000
Enterprise	300	100,000

Rate limit headers are included in responses:

X-RateLimit-Limit: 60
X-RateLimit-Remaining: 58
X-RateLimit-Reset: 1707145200
                

SDKs & Libraries

Official SDKs for popular languages:

Python

pip install sendfiles

Node.js

npm install sendfiles

PHP

composer require sendfiles/sdk

Python Example

from sendfiles import SendFilesClient

client = SendFilesClient("YOUR_API_KEY")

# Create and upload
transfer = client.create_transfer(message="Project files")
transfer.upload("/path/to/file.zip")
transfer.finalize()

print(f"Download URL: {transfer.download_url}")
                

ON THIS PAGE

Overview

Authentication

Create Transfer

Request Body

Example Request

Response

Upload File

Request Body (multipart/form-data)

Example Request

Response

Finalize Transfer

Example Request

Response

Get Transfer

Example Request

Response

List Transfers

Query Parameters

Response

Delete Transfer

Example Request

Response

Webhooks

Events

Webhook Payload

Error Handling

Error Response

Rate Limits

SDKs & Libraries

Python

Node.js

PHP

Python Example

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