Sinch Agent Tools · CLI

Sinch CLI: Build, test, and deploy from your terminal

The Sinch CLI is a command line tool for configuring, testing, and managing your Sinch Build products. Rent numbers, send messages, store secrets, and ship Sinch Functions without leaving your terminal.

  • Manages numbers, messaging, voice, fax, SIP trunking, and Sinch Functions

  • Stores credentials in your OS keychain, not a plaintext config file

  • Runs under an AI agent without exposing your secrets to it

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Installs from npm in one command. Live API calls need a Sinch account.

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Terminal-first workflow

Your whole Build workflow in one terminal

You shouldn’t have to open a web dashboard just to rent a number, send a test message, or check why a workflow failed. The Sinch CLI puts those tasks in the terminal you’re already coding in. Install one package, log in once, and you have command line access to your Sinch Build products.

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Install and authenticate

One package, one login, every project

The Sinch CLI installs as a single npm package and authenticates once. Your credentials go into the OS keychain rather than a config file, so they don’t leak into shell history or source control. Login supports profiles, so one install can switch between multiple Sinch Build projects.

                            

                                npm install -g @sinch/cli
sinch auth login     # prompts for Project ID, Key ID, and Key Secret, stored in your OS keychain
sinch auth status    # confirm the login worked

Full portal coverage

One session covers your whole Build portal

One authenticated session reaches numbers, messaging, voice, fax, SIP trunking, and secrets – every Sinch Build product except Mailgun. There’s no separate login per product, and no dashboard round trip to make a change.

                            

                                sinch numbers available search --region US --type LOCAL --capabilities SMS
sinch numbers available rent                          # interactive: pick a number, confirm the cost
sinch conversation send +15559876543 "Hello from the Sinch CLI"
sinch secrets add STRIPE_SECRET_KEY sk_live_abc123    # readable by your deployed Functions
sinch numbers active release +15551234567             # stop billing when you're done testing

From template to production

Scaffold, test, and ship in a few commands

Sinch Functions is serverless compute for voice and messaging. The CLI takes you from a starter template to production without opening the dashboard once. Every flag sits in the Functions command reference.

Explore Sinch Functions 
                            

                                sinch functions init      # scaffold a new project from a template    
    sinch functions dev       # run and test locally against a public tunnel    
    sinch functions deploy    # ship to production    
    sinch functions logs      # monitor a live function

Agent-safe credentials

Let an AI agent drive the CLI safely

Login happens once, at install. An AI coding agent can then run CLI commands on your behalf without ever seeing, requesting, or storing your credentials. The agent invokes commands, and your secrets stay in the OS keychain.

  • Keeps secrets out of an agent’s context – you log in once, at install

  • Works with Claude Code, Cursor, and other terminal agents

  • Offers to install the matching Sinch Skills during login, so your agent gets the same operational guidance you would

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CLI use cases

What developers do with the Sinch CLI

Four common patterns, from one-off resource changes to handing the busywork to an agent.

Rent a number and text it, no code

Search for an SMS-capable number, rent it, and send your first message from the same terminal session – no dashboard, no deploy.

Ship a workflow in one sitting

Scaffold an SMS auto-responder with sinch functions init, wire up the trigger, and deploy – without opening the dashboard.

Test locally before going live

Run sinch functions dev against a public tunnel, trigger it with real test events, then deploy once the behavior is right.

Let an agent do the busywork

An AI coding agent runs the CLI to manage resources and deploy functions, while your credentials stay in the keychain.

The CLI and the rest of Agent Tools

Where the CLI fits in Sinch Agent Tools

The Sinch CLI is one of six Agent Tools components, and it ties several together. Installing it offers the matching Skills for the products you use, and those Skills reference the SDKs your agent builds with. The CLI deploys the result to Functions, while MCP and plugins connect your agent from other tools. Each works on its own, and they work better together.

Explore Agent Tools
Explore Sinch Functions

Frequently asked questions about the Sinch CLI

Quick answers on what the Sinch CLI manages, where credentials are stored, and what you need to run it.

A command line tool for configuring, testing, and managing Sinch Build products, and for building, testing, and deploying Sinch Functions, from your terminal.

Phone numbers, messaging across Conversation API channels, voice, fax, SIP trunking, secrets, and Sinch Functions. Mailgun is the one Sinch Build product it doesn’t cover yet.

Install the single npm package with npm install -g @sinch/cli, then run sinch auth login once.

In your operating system keychain, not a plaintext config file, so they don’t leak into shell history or source control. Login supports profiles, so one install can switch between multiple projects.

Yes. You log in once at install, so an agent can run commands without ever seeing, requesting, or storing your secrets.

Windows 10 or later, macOS 12 or later, or a modern Linux distribution. Node.js 20 or later for Node.js functions, and the .NET 9 SDK or later for C# functions. Shell completions are available for bash, zsh, and PowerShell – the installation guide covers setup per platform.

It’s one component of Sinch Agent Tools, the developer layer for building on Sinch APIs. Agent Tools sits inside a broader set of AI capabilities spanning messaging, voice, email, and verification.

Explore Sinch AI

Install the CLI, run sinch auth login, then follow the quickstart to rent a number and send your first SMS – no code and no deploys.

View the quickstart