TypeScript icon, indicating that this package has built-in type declarations

4.0.2 • Public • Published


CLI tool to locally develop and deploy to the Twilio Runtime. Part of the Serverless Toolkit

npm (scoped) npm GitHub All Contributors Code of Conduct PRs Welcome


This project is part of the Serverless Toolkit. For a more extended documentation, check out the Twilio Docs.


You can install the CLI tool via npm or another package manager. Ideally install it as a dev dependency instead of global:

# Install it as a dev dependency
npm install twilio-run --save-dev

# Afterwards you can use by using:

npx twilio-run

# Or inside your package.json scripts section as "twilio-run"


Check out the commands for in depth usage, but here are some things you will want to know:

Create a new project

To create a new project with the Twilio Serverless Toolkit you can use create-twilio-function which will scaffold a new project that is ready to be used with twilio-run.

# Create a valid project, for example:
npm init twilio-function my-project

# Navigate into project
cd my-project

You can then use twilio-run to run a local development server to serve your functions and assets.

npx twilio-run start

Project conventions

By default JavaScript Functions should be placed in the functions directory and assets, which can be JavaScript, images, CSS, or any static asset, should be placed in the assets directory. You can choose other directories by providing a --functions-folder or --assets-folder option to twilio-run commands.

Twilio Functions and Assets can be public, protected or private. The differences are:

  • Public: Any one with the URL can visit the Function or Asset
  • Protected: Twilio signs webhook requests, making a Twilio Function protected means that the Function will validate the webhook signature and reject any incoming requests that don't match
  • Private: The Function or Asset doesn't a URL, it can only be required within another Function or Asset

Within twilio-run you can make your Functions or Assets public, protected or private by adding to the function filename. Functions and Assets are public by default. To make a Function or Asset protected or private, add .protected or .private to the filename before the extension. For example: functions/secret.protected.js or assets/hidden.private.jpg.

Function templates

There are a number of pre-written Function templates that you can add to your project. The templates are available on GitHub and you can also propose your own via pull request.

To list the available templates you can run:

npx twilio-run list-templates

To add a new function into your project from a template you can run:

npx twilio-run new namespace

The command will walk you through choosing the template.

Deploy a project

To deploy a project to the Twilio infrastructure you can run the command:

npx twilio-run deploy

This will deploy your project to the "dev" environment by default. You can then promote the project from "dev" to other environments with the command:

npx twilio-run promote --from=dev --to=stage


The CLI exposes a variety of commands. The best way to find out about the flags and commands available is to run twilio-run --help or twilio-run [command] --help

twilio-run start [dir]

  • Aliases: twilio-run dev, twilio-run

Starts a local development server for testing and debugging of your environment. By default only variables in the .env file will be available via process.env or through the context argument inside Twilio Functions.


# Serves all functions in current functions sub directory

# Serves all functions in demo/functions
twilio-run demo

# Serves functions on port 9000
PORT=9000 twilio-run

# Serves functions on port 4200
twilio-run --port=4200

# Starts up the inspector mode for the node process
twilio-run --inspect

# Exposes the Twilio functions via ngrok to share them
twilio-run --ngrok

# Exposes the Twilio functions via ngrok using a custom subdomain (requires a paid-for ngrok account)
twilio-run --ngrok=subdomain

twilio-run deploy

Deploys your project to Twilio. It will read dependencies automatically from your package.json's dependencies field and install them. It will also upload and set the variables that are specified in your .env file. You can point it against a different .env file via command-line flags.


# Deploys all functions and assets in the current working directory
twilio-run deploy

# Creates an environment with the domain suffix "prod"
twilio-run deploy --environment=prod

twilio-run list-templates

Lists the available templates that you can use to generate new functions and/or assets inside your current project with the twilio-run new command below.


# List available templates
twilio-run list-templates

twilio-run new [namespace]

Creates a new set of functions and/or assets inside your current project based on a template.


# Create a new function using the blank template
# in a subfolder (namespace) demo
twilio-run new demo --template=blank

twilio-run list [types]

Lists a set of available resources for different types related to your Account. Available resources that can be listed:

  • Services
  • Environments or Builds (requires to pass a Service)
  • Functions, Assets or Variables (requires to pass a Service and Environment)


# Lists all existing services/projects associated with your Twilio Account
twilio-run list services
# Lists all existing functions & assets associated with the `dev` environment of this service/project
twilio-run ls functions,assets --environment=dev --service-name=demo
# Outputs all environments for a specific service with extended output for better parsing
twilio-run ls environments --service-sid=ZSxxxxx --extended-output
# Only lists the SIDs and dates of last update for assets, variables and functions
twilio-run ls assets,variables,functions --properties=sid,date_updated

twilio-run activate

  • Aliases: twilio-run promote

Promotes an existing deployment to a new environment. It can also create a new environment if it doesn't exist.


# Promotes the same build that is on the "dev" environment to the "prod" environment
twilio-run activate --environment=prod --source-environment=dev
# Duplicates an existing build to a new environment called `demo`
twilio-run activate --environment=demo --create-environment --build-sid=ZB1234xxxxxxxxxx

twilio-run logs

Print logs from your Twilio Serverless project


# Gets the latest logs for the current project in the dev environment
twilio-run logs
# Continuously streams the latest logs for the current project in the dev environment
twilio-run logs --tail
# Gets the latest logs for the function sid in the production environment
twilio-run logs --function-sid ZFXXX --environment production


The module also exposes two functions that you can use outside of the CLI tool to spin up local development.

If you want to interact with the Runtime API instead, check out the @twilio-labs/serverless-api package.

runDevServer(port: number, baseDir: string): Promise<Express.Application>

This allows you to trigger running an express server that will expose all functions and assets. Example:

const { runDevServer } = require('twilio-run');

  .then(app => {
    console.log(`Server is running on port ${app.get('port')})`);
  .catch(err => {
    console.error('Something failed');

handleToExpressRoute(handler: TwilioHandlerFunction): Express.RequestHandler

You can take the handler function of a Twilio Function file and expose it in an existing Express server. Example:

const express = require('express');
const bodyParser = require('body-parser');
const { handlerToExpressRoute } = require('twilio-run');

const { handler } = require('./path/to/function.js');

const app = express();
app.use(bodyParser.urlencoded({ extended: false }));


app.listen(3000, () => console.log('Server running on port 3000'));

Error Handling in Dev Server

If your local Twilio Function throws an unhandled error or returns an Error instance via the callback method, we will return an HTTP status code of 500 and return the error object as JSON.

By default we will clean up the stack trace for you to remove internal code of the dev server and add it as at [Twilio Dev Server internals] into the stack trace.

An example would look like this:

Error: What?
    at format (/Users/dkundel/dev/twilio-run/examples/basic/functions/hello.js:5:9)
    at exports.handler (/Users/dkundel/dev/twilio-run/examples/basic/functions/hello.js:13:3)
    at [Twilio Dev Server internals]

If you want to have the full un-modified stack trace instead, set the following environment variable, either in your Twilio Function or via .env:


This will result into a stack trace like this:

Error: What?
    at format (/Users/dkundel/dev/twilio-run/examples/basic/functions/hello.js:5:9)
    at exports.handler (/Users/dkundel/dev/twilio-run/examples/basic/functions/hello.js:13:3)
    at twilioFunctionHandler (/Users/dkundel/dev/twilio-run/dist/runtime/route.js:125:13)
    at app.all (/Users/dkundel/dev/twilio-run/dist/runtime/server.js:122:82)
    at Layer.handle [as handle_request] (/Users/dkundel/dev/twilio-run/node_modules/express/lib/router/layer.js:95:5)
    at next (/Users/dkundel/dev/twilio-run/node_modules/express/lib/router/route.js:137:13)
    at next (/Users/dkundel/dev/twilio-run/node_modules/express/lib/router/route.js:131:14)
    at next (/Users/dkundel/dev/twilio-run/node_modules/express/lib/router/route.js:131:14)
    at next (/Users/dkundel/dev/twilio-run/node_modules/express/lib/router/route.js:131:14)
    at next (/Users/dkundel/dev/twilio-run/node_modules/express/lib/router/route.js:131:14)

In general you'll want to use the cleaned-up stack trace since the internals might change throughout time.


This project welcomes contributions from the community. Please see the file for more details.

Code of Conduct

Please be aware that this project has a Code of Conduct. The tldr; is to just be excellent to each other ❤️


Thanks goes to these wonderful people (emoji key):

Dominik Kundel
Dominik Kundel


💻 🐛
Shelby Hagman
Shelby Hagman

🐛 💻
JavaScript Joe
JavaScript Joe

Stefan Judis
Stefan Judis

🐛 💻
Phil Nash
Phil Nash

🐛 💻 👀

This project follows the all-contributors specification. Contributions of any kind welcome!



Package Sidebar


npm i twilio-run

Weekly Downloads






Unpacked Size

322 kB

Total Files


Last publish


  • twilio-serverless
  • twilio-labs-ci