Sigmo (Formerly Telmo)

Sigmo is a modern, self-hosted web UI and API for managing ModemManager-based cellular modems. It ships as a single binary with an embedded Vue 3 frontend, designed to be lightweight and easy to deploy.

Sigmo focuses on advanced eSIM operations, SMS management, and network control.

✨ Features

• 📱 eSIM Management: List, download (SM-DP+), enable, rename, and delete eSIM profiles.
• 📩 SMS Center: Full conversational view for SMS, send/delete capability, and USSD session support.
• ⚙️ Modem Control: SIM slot switching, network scanning, manual registration, and preference configuration (Alias, MSS).
• 🔒 Secure Access: OTP-based login system via Telegram, HTTP, Email, and more.
• 🔔 Notifications: Forward incoming SMS and login tokens to Telegram, Bark, Gotify, Email, etc.
• 🚀 Portable: Single Go binary with no external runtime dependencies (except ModemManager).

---

🛍️ Recommended Hardware & Offers

Support the project and get reliable hardware for your setup.

• Need an eUICC? We recommend eSTK.me. It is highly reliable for iOS profile downloads.

  🎁 Use code esimcyou for 10% off.

• Need more storage? If you require >1MB storage to install multiple eSIM profiles, we recommend 9eSIM.

  🎁 Use code DAMON for 10% off.

---

🛠 Architecture & Requirements

Architecture:

• Backend: Go serving /api/v1 and static assets.
• Frontend: Vue 3 + Vite (Embedded in the binary).

System Requirements:

• OS: Linux.
• Service: ModemManager running on the system D-Bus.
• Permissions: Root access or proper udev rules to access modem device nodes.

---

📥 Installation

Sigmo is distributed as a static binary. You do not need to install Node.js or Go to run it.

1. Download Binary

Grab the latest release for your architecture from the GitHub Releases.

# Example for Linux AMD64
curl -LO https://github.com/damonto/sigmo/releases/latest/download/sigmo-linux-amd64
chmod +x sigmo-linux-amd64
sudo install -m 0755 sigmo-linux-amd64 /usr/local/bin/sigmo

2. Configure

Create the configuration directory and file.

sudo mkdir -p /etc/sigmo
# Download example config
curl -L https://raw.githubusercontent.com/damonto/sigmo/main/configs/config.example.toml | sudo tee /etc/sigmo/config.toml >/dev/null

3. Run

Start the service.

/usr/local/bin/sigmo -config /etc/sigmo/config.toml

Visit http://localhost:9527 to access the UI.

---

⚙️ Configuration Reference

Sigmo runs using a TOML configuration file (default: /etc/sigmo/config.toml).

⚠️ Important: This file is Read-Write. When you update modem aliases or settings via the Web UI, Sigmo writes the changes back to this file. Ensure the Sigmo process has write permissions to the config file.

1. [app] General Settings

Controls the core application behavior, network binding, and security policies.

[app]
  environment = "production"
  listen_address = "0.0.0.0:9527"
  auth_providers = ["telegram", "email"]
  otp_required = true

Parameter	Type	Description
environment	String	The running environment. Set to "production" to minimize logs (recommended). Set to "development" to enable verbose debug logging.
listen_address	String	The IP and Port to bind the HTTP server. 0.0.0.0:9527 listens on all interfaces. 127.0.0.1:9527 restricts access to localhost.
auth_providers	Array	Allowed login channels. The values listed here must match the configuration block names in [channels] (e.g., telegram, bark, email).
otp_required	Boolean	Enforce OTP (One-Time Password) for login. true: Secure mode (Recommended). false: No login required (Insecure, for isolated internal networks only).

2. [channels] Notification & Auth

Configures channels used for receiving Login OTPs and Forwarded SMS.

Note: If no channels are configured, OTP login and SMS forwarding features will be automatically disabled.

Telegram

[channels.telegram]
  bot_token = "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11"
  recipients = [123456789, 987654321]

• bot_token: The token received from @BotFather.
• recipients: Array of Integer Chat IDs authorized to receive messages.

Bark (iOS Push)

[channels.bark]
  endpoint = "https://api.day.app"
  recipients = ["device_key_1", "device_key_2"]
  subject = "Sigmo Alert"

• endpoint: Bark server URL. Leave empty to use the official https://api.day.app. Sigmo automatically appends /push.
• recipients: List of Device Keys from the Bark App.
• subject: The title of the push notification.

Gotify (Self-Hosted)

[channels.gotify]
  endpoint = "https://push.example.com"
  recipients = ["AsDh82..."]
  subject = "Sigmo Notification"
  priority = 5

• endpoint: Base URL of your Gotify server (do not add /message; it is appended automatically).
• recipients: List of Gotify Application Tokens.
• priority: Message priority (Integer), default is 5.

ServerChan (SendKey)

[channels.sc3]
  endpoint = "https://<uid>.push.ft07.com/send/<sendkey>.send"
  subject = "Sigmo Login"

• endpoint: The full URL including the SendKey.
• subject: Message title.

HTTP (Webhook)

[channels.http]
  endpoint = "https://httpbin.org/post"
  [channels.http.headers]
    Authorization = "Bearer secret_token"
    Content-Type = "application/json"

• endpoint: The target Webhook URL.
• headers: Key-Value pairs for custom HTTP headers. Sigmo sends a JSON payload containing the message body.

Email (SMTP)

[channels.email]
  smtp_host = "smtp.gmail.com"
  smtp_port = 587
  smtp_username = "yourname@gmail.com"
  smtp_password = "app_password"
  from = "Sigmo <yourname@gmail.com>"
  recipients = ["admin@example.com"]
  subject = "Sigmo Alert"
  tls_policy = "mandatory"
  ssl = false

• smtp_host / smtp_port: Server address and port.
• smtp_username / smtp_password: Credentials (App Passwords are recommended).
• recipients: List of email addresses to receive notifications.
• tls_policy: STARTTLS enforcement.
  • mandatory: Enforce TLS (Default, Recommended).
  • opportunistic: Try TLS, fall back to plain text if unavailable.
  • none: No TLS.
• ssl: Use implicit SSL (usually for port 465). Set true for port 465. Set false for port 587 (when using tls_policy).

3. [modems] Hardware Settings

This section is auto-generated by Sigmo when you save settings in the Web UI. You generally do not need to write this manually.

Entries are keyed by the ModemManager Equipment Identifier.

[modems]
  [modems."123456789012345"]
    alias = "Office 5G Stick"
    compatible = false
    mss = 240

Parameter	Type	Default	Description
alias	String	(None)	Custom Name. Displayed in the Web UI to help identify specific modems/SIMs.
compatible	Boolean	false	Compatibility Mode. Some older modems lose network connectivity after switching eSIM profiles unless fully rebooted. If enabled, Sigmo will try to restart the modem device after profile operations.
mss	Int	240	Max Segment Size. Controls the APDU payload size (range 64-254) for SIM communication. • If you experience errors during profile download, try lowering this value (e.g., 128 or 64). • Most modern modems work fine with the default 240.

---

💻 Service Deployment

To run Sigmo as a background service, use Systemd.

Systemd Example

1. Install Unit File:

   sudo install -m 0644 init/systemd/sigmo.service /etc/systemd/system/sigmo.service

2. Enable & Start:

   sudo systemctl daemon-reload
   sudo systemctl enable --now sigmo

Note: The default service runs as root to ensure access to ModemManager. If running as a non-root user, verify udev rules for the modem and file permissions for /etc/sigmo/config.toml.

---

🏗️ Development

If you wish to contribute or modify the source:

1. Prerequisites: Go 1.25+, Bun (for Vue).
2. Setup Config: cp configs/config.example.toml config.toml
3. Build Frontend:

   cd web && bun install && bun run build

4. Run Backend:

   go run ./ -config config.toml

   Or for frontend hot-reload: cd web && bun run dev

---

📄 License

Released under the MIT License.