Installation

For Node.js functions, you also need Node.js 20+. For C# functions, you need .NET 9 SDK or later.

npm install -g @sinch/cli

Install takes a few seconds. npm automatically selects the right native binary for your platform — no install scripts run, so npm install --ignore-scripts works fine.

Do not use --omit=optional. The CLI binary ships as an optional dependency; if it is skipped the CLI prints an actionable error telling you how to fix it.

If you don't already have Node.js, install Node.js 20+ first — npm comes with it.

Verify:

sinch --version

sinch auth login

Enter your Project ID, Key ID, and Key Secret from the Sinch Dashboard under your project's Access Keys section.

Key secrets are stored in your OS keychain (Windows Credential Manager, macOS Keychain, or Linux Secret Service). Short-lived session tokens are stored in your local config (~/.sinch/).

Voice templates run on Voice API v2, which authenticates with the project key pair above. sinch functions init runs a Voice service picker for every voice template and writes the picked VOICE_SERVICE_ID into the new function's .env or appsettings.json; you can skip the picker and set the value later. A Voice Application Key and Secret are needed only by the legacy sinch voice v1 commands, and are supplied with -a, --app-key or the SINCH_APPLICATION_KEY / SINCH_APPLICATION_SECRET environment variables.

The CLI silently refreshes ~/.sinch/completions.json on startup. On first run it prints a one-time hint about enabling completions. To install completions into your shell profile:

sinch completion --install

To print the completion script to stdout (e.g. for custom setups):

sinch completion --shell bash    # Bash
sinch completion --shell zsh     # Zsh
sinch completion --shell powershell  # PowerShell

npm install -g @sinch/cli

The CLI checks for new versions in the background and prints a notice when one is available. The check is rate limited to once every 30 minutes and stays quiet in CI, in Docker, when output is piped, and under --json or --non-interactive.

The CLI can also install updates for you. This is off by default:

sinch config set autoUpdate true    # opt in
sinch upgrade                       # check right now, ignoring the rate limit
sinch upgrade --status              # what it knows
sinch config set autoUpdate false   # opt back out

When it is on and an update is available, the CLI records what it wants to install, starts a background helper, and prints one line. Your command then runs and exits on the version you started with. The helper waits for the CLI to exit before installing, so nothing is replaced underneath a running command, and the new version takes effect on a later run.

It will not update itself in every situation, and says which applies:

If an install does not land cleanly, the helper puts the previous version back rather than leaving you with a CLI that cannot start.

npm uninstall -g @sinch/cli
sinch auth logout  # remove stored credentials