docs(readme): update API URL to HTTPS domain, add deployment/SSL/traffic info

README.md

@@ -33,6 +33,14 @@ python app.py
 - Web UI: http://localhost:5000
 - API: see /api/upload and /api/file endpoints
 
+Deployment
+
+The production instance runs at:
+- **Domain**: `xiaji-temp.duckdns.org`
+- **HTTPS**: Let's Encrypt SSL with auto-renewal (certbot timer)
+- **Nginx**: reverse proxy with 500MB upload limit, 80→443 redirect
+- **Gunicorn**: 4 workers, systemd-managed
+
 Project layout
 - app.py               # Flask application
 - config.py            # Configuration constants
@@ -57,6 +65,16 @@ Expiry and cleanup
 - A cleanup operation removes expired files from disk and deletes DB rows
 - Cleanup is invoked on access endpoints (and can be wired to a cron/daemon later)
 
+Traffic limits
+- Maximum file size: 500 MB
+- Per-IP daily traffic limit: 20 GB (upload + download combined)
+- IP traffic tracked in SQLite `ip_traffic` table, reset daily
+
+SSL certificate
+- Let's Encrypt certificate deployed via certbot
+- Auto-renewal via systemd timer: `certbot.timer`
+- Manual renewal test: `certbot renew --dry-run`
+
 Security notes
 - Do not commit secrets. Secrets should be provided via environment variables in production.
 - This repository currently avoids embedding credentials.
@@ -69,6 +87,59 @@ Next steps (optional)
 License
 - MIT or your preferred license (update as needed)
 
+API Usage (Python)
+
+Upload a file via the API endpoint:
+
+```python
+import requests
+
+BASE_URL = "https://xiaji-temp.duckdns.org"
+
+expiry = "24h"  # 1h, 24h, 7d
+
+with open("/path/to/your/file.zip", "rb") as f:
+    resp = requests.post(
+        f"{BASE_URL}/api/upload",
+        files={"file": ("file.zip", f)},
+        data={"expiry": expiry},
+    )
+
+if resp.status_code == 200:
+    data = resp.json()
+    print(f"Share URL: {data['share_url']}")
+    print(f"File ID: {data['id']}")
+    print(f"Size: {data['filesize']} bytes")
+else:
+    print(f"Upload failed: {resp.json()['error']}")
+```
+
+Response format:
+```json
+{
+    "id": "550e8400-e29b-41d4-a716-446655440000",
+    "filename": "file.zip",
+    "filesize": 1048576,
+    "expiry_hours": 24,
+    "share_url": "https://xiaji-temp.duckdns.org/file/550e8400..."
+}
+```
+
+Get file info via API:
+```python
+resp = requests.get(f"{BASE_URL}/api/file/{file_id}")
+if resp.status_code == 200:
+    info = resp.json()
+    print(f"Daily upload: {info['daily_upload']} bytes")
+    print(f"Daily download: {info['daily_download']} bytes")
+    print(f"Traffic limit: {info['traffic_limit']} bytes (20GB)")
+```
+
+Or use the bundled client script:
+```bash
+python upload_client.py /path/to/file.zip 24h
+```
+
 Contributing
 - Pull requests are welcome. Please follow the project style and ensure tests pass.