Swift Print

Swift Print is a small Windows utility that exposes a local HTTP API for sending raw print data to installed printers. It runs in the system tray, listens only on 127.0.0.1, and protects print endpoints with a secret token.

It is designed for browser printing, POS printing, kiosk printing, receipt printing, ESC/POS commands, thermal printers, and other raw printer workflows that need a simple local print bridge.

Features

• Windows system tray app
• Local-only HTTP server
• Raw print support for TCP, USB, LPT, COM, and spooler fallback paths
• Printer discovery from the Windows registry
• Simple settings page for port and token changes
• Optional single-file installer build
• Useful for browser printing, POS printing, receipt printing, and local print bridge integrations

Project Layout

cmd/
  swift-print/             Main tray app and local print server
  swift-print-installer/   Installer command
examples/test.html         Browser smoke-test page
config.example.json        Example runtime config

The old local project folders are ignored so this repository can be published without generated binaries, debug builds, or private config files.

Security Notes

Swift Print controls local printers, so treat the token like a password.

• Keep the server bound to 127.0.0.1.
• Do not publish your real config.json.
• The default secret_token is change-me; change it before using Swift Print.
• Send the token with API requests as the X-API-KEY header.
• Browser clients can call the API by sending the X-API-KEY header.
• The settings page accepts changes only from same-origin localhost requests.

If config.json is missing, Swift Print creates one beside the executable with port 1818 and token change-me.

Build

Swift Print is a Windows app. If you build from Linux or macOS, set GOOS=windows GOARCH=amd64 as shown below.

First install rsrc and generate the Windows icon resources. Do this before building so the generated rsrc.syso files are included in the executables:

go install github.com/akavel/rsrc@latest
mkdir -p dist
rsrc -ico cmd/swift-print/swiftprint.ico -arch amd64 -o cmd/swift-print/rsrc.syso
rsrc -ico cmd/swift-print-installer/swiftprint.ico -arch amd64 -o cmd/swift-print-installer/rsrc.syso

After the icon resources are generated, build from Windows with:

go build -ldflags "-H=windowsgui" -o "dist/Swift Print.exe" ./cmd/swift-print
go build -o "dist/Swift Print Installer.exe" ./cmd/swift-print-installer

If you are building from Linux or macOS, cross-build with:

GOOS=windows GOARCH=amd64 go build -ldflags "-H=windowsgui" -o "dist/Swift Print.exe" ./cmd/swift-print
GOOS=windows GOARCH=amd64 go build -o "dist/Swift Print Installer.exe" ./cmd/swift-print-installer

Single-File Installer Release

To embed the app and config inside the installer, place release payload files in:

cmd/swift-print-installer/payload/Swift Print.exe
cmd/swift-print-installer/payload/config.json

Then build the installer command. The payload files are ignored by Git, but Go will embed them into the installer binary when they exist at build time.

Runtime Config

Example:

{
  "port": "1818",
  "secret_token": "change-me"
}

Copy config.example.json to config.json for local testing, then change the token before use.

API

Health check:

GET / HTTP/1.1
Host: 127.0.0.1:1818

List printers:

GET /printers HTTP/1.1
Host: 127.0.0.1:1818
X-API-KEY: your-secret-token

Print raw base64 data:

POST /print HTTP/1.1
Host: 127.0.0.1:1818
Content-Type: application/json
X-API-KEY: your-secret-token

{
  "printer": "Printer Name",
  "data": "BASE64_ENCODED_RAW_PRINT_BYTES"
}

Browser smoke test:

examples/test.html

Open the file in a browser, enter the Swift Print port and secret token, then load printers or send a small test print.

License

Swift Print is released under the MIT License. See LICENSE for details.