FTP to Webhook

Legacy partners, EDI systems, accounting packages, and carrier integrations still speak FTP. Your stack speaks HTTP. Instead of running an SFTP box and polling it with a cron job, FTPasHTTPS acts as the bridge: it terminates the FTP connection and forwards each uploaded file to your API as a real-time webhook. This guide shows the exact config and the payload your endpoint receives.

How FTP-to-webhook works

FTPasHTTPS is a virtualized FTP server. There is no filesystem behind it — every upload is a stream that maps onto an HTTP request.

1. Your partner connects with any FTP, FTPS, or SFTP client and authenticates against a user you created.
2. They issue an STOR to upload a file. FTPasHTTPS opens the data connection and begins reading bytes.
3. Those bytes are streamed into the body of an HTTPS POST to your configured webhook URL, with file metadata in the headers.
4. Your endpoint processes the file and returns an HTTP status. 2xx → FTP 226 Transfer complete; 5xx → FTP 451 Action aborted.
5. If the POST fails, FTPasHTTPS retries with exponential backoff, then routes to a dead-letter queue. Every attempt is written to the audit log.

Config & example webhook payload

Configure the webhook once on your FTPasHTTPS server. A minimal server definition looks like this:

server.config

# FTPasHTTPS server configuration
protocol:        FTPS            # FTP | FTPS | SFTP
mode:            passive         # active + passive supported
webhook:
  url:           https://api.example.com/ingest/ftp
  method:        POST
  sign_with:     hmac-sha256     # X-FTPasHTTPS-Signature header
  retries:       5               # exponential backoff
  dead_letter:   true
users:
  - username:    acme-partner
    auth:        password        # or ssh-key for SFTP

When acme-partner uploads orders-2026-06-20.csv, your endpoint receives a request whose body is the raw file and whose headers carry the metadata. A JSON envelope is also available if you prefer structured delivery:

POST https://api.example.com/ingest/ftp

Content-Type: application/octet-stream
X-FTPasHTTPS-Signature: sha256=9f86d081884c7d659a2feaa0c55ad015...
X-FTPasHTTPS-Event: file.uploaded

{
  "event": "file.uploaded",
  "server": "acme-prod",
  "protocol": "FTPS",
  "file": {
    "name": "orders-2026-06-20.csv",
    "path": "/inbound/orders-2026-06-20.csv",
    "size_bytes": 48213,
    "sha256": "e3b0c44298fc1c149afbf4c8996fb924..."
  },
  "user": "acme-partner",
  "received_at": "2026-06-20T08:14:02Z"
}

Verify the X-FTPasHTTPS-Signature header against your shared secret before trusting the payload, then return 200 OK to complete the FTP transfer.

FTPasHTTPS vs the DIY way

The traditional approach is an SFTP server plus a cron job that polls a directory and shells out to a script. Here is how the two compare:

	DIY: SFTP box + cron + script	FTPasHTTPS
Latency	As slow as your cron interval (1–15 min)	Near-instant — POST fires during the upload
Files on disk	Yes — landing dir, attack surface, cleanup	None — streamed in memory
Retries	You build them	Automatic backoff + dead-letter queue
Auth of payload	Roll your own	HMAC-SHA256 signed webhooks
Ops burden	Patch SSH, rotate keys, monitor cron	Managed — you configure a URL
Audit trail	grep through logs	Full structured audit logs

When to use FTP-to-webhook

• A partner can only push files over FTP/FTPS/SFTP but your app is API-driven.
• You want uploads processed the moment they arrive, not on a polling schedule.
• You need to drop the SFTP box and cron job you are currently babysitting.
• Compliance wants no files sitting at rest on an ingestion server.
• You need a signed, auditable trail of every file received.

If your real goal is to land files in object storage rather than call an API, see the SFTP to S3 guide instead — FTPasHTTPS can forward to S3, GCS, Azure, or another SFTP server natively.

Protocols, modes, and what each plan unlocks

FTPasHTTPS implements FTP (RFC 959), FTPS (RFC 4217 over TLS 1.2/1.3), and SFTP (SSH key auth). Both active and passive data modes are supported, over IPv4 and IPv6, so even strict legacy clients connect without changes on their side. The webhook bridge described above works the same regardless of which protocol the client speaks — the protocol only changes how the client authenticates and negotiates the data channel, not how the bytes reach your endpoint.

Webhooks themselves start on the Starter plan (€19/server/month: 1,000 transfers, FTP+FTPS). The Free plan (€0, no credit card) is FTP-only with 100 transfers a month, which is enough to prototype the integration end to end. Professional (€49) adds SFTP, custom domains, inline transformations, and schema validation; Enterprise (€99) adds SSO/SAML, a dedicated IP, and PGP. Pick the lowest tier that covers the protocols and volume your partners need, then upgrade as you onboard more of them.

Frequently asked questions