Fallen Downloader

Fallen Downloader is an open-source Go web app for downloading media from supported social and music URLs.

Users can paste a supported link, pass Cloudflare Turnstile verification, and fetch downloadable media via api.fallenapi.fun.

It serves a built-in frontend and exposes a small API used by that frontend.

Features

• Web UI with platform detection for social and music URLs
• Snap workflow for video/audio/image extraction
• Music workflow for track search and download
• Cloudflare Turnstile verification on /api/* routes
• Embedded templates and static assets (single Go binary)
• Dockerfile and Docker Compose support

Tech Stack

• Go 1.26+
• Fiber v3
• Cloudflare Turnstile
• External provider API: https://api.fallenapi.fun

Project Structure

.
|- main.go
|- internal/
|  |- api/
|  |- config/
|  `- httpx/
`- templates/

Configuration

The app uses environment variables (auto-loaded from .env via godotenv/autoload).

Copy sample.env to .env and update values.

Variable	Required	Default	Description
API_KEY	Yes	-	API key sent to upstream provider in X-API-Key
API_URL	No	https://api.fallenapi.fun	Base URL for upstream provider
PORT	No	8080	HTTP server port
TURNSTILE_SECRET	Yes	-	Secret used to verify X-CF-Turnstile-Token
TURNSTILE_SITE_KEY	Recommended	empty	Site key injected into frontend Turnstile widget

Run Locally

git clone https://github.com/FallenProjects/fallen-downloader
cd fallen-downloader
cp sample.env .env
# edit .env with your real values
go run .

Then open:

• http://localhost:8080/ - web UI
• http://localhost:8080/health - health check

Run with Docker Compose

git clone https://github.com/FallenProjects/fallen-downloader
cd fallen-downloader
cp sample.env .env
# edit .env with your real values
docker compose up --build -d

Stop:

docker compose down

API Endpoints (this app)

All /api/* routes require header X-CF-Turnstile-Token.

• GET /api/snap?url=<target_url>
• GET /api/info?url=<target_url>
• GET /api/dl?url=<target_url>

Health endpoint does not require Turnstile:

• GET /health

Example request:

curl -sS "http://localhost:8080/api/snap?url=https://www.instagram.com/reel/abc" \
  -H "X-CF-Turnstile-Token: <turnstile_token>"

Internal Flow

1. Browser calls this app's /api/* endpoint.
2. Middleware validates Turnstile token with Cloudflare.
3. Server calls upstream provider using API_KEY.
4. Response is returned to browser and frontend triggers download links.

Observability

• Request logs enabled (except /stream)
• Panic recovery middleware enabled
• pprof middleware enabled (Fiber default pprof routes)

Development Notes

• Templates and static files are embedded with go:embed.
• CORS is currently permissive (*).
• The frontend supports multiple URL patterns (Instagram, TikTok, Spotify, etc.) defined in templates/app.js.

License

Licensed under the MIT License. See LICENSE.