Awesome Open Source
Awesome Open Source


Build Status Go Report Card License: MIT OpenFaaS

faas-cli is the official CLI for OpenFaaS

Run a demo with faas-cli --help

The CLI can be used to build and deploy functions to OpenFaaS. You can build OpenFaaS functions from a set of supported language templates (such as Node.js, Python, CSharp and Ruby). That means you just write a handler file such as ( and the CLI does the rest to create a Docker image.

New user? See how it works: Morning coffee with the faas-cli Already an OpenFaaS user? Try 5 tips and tricks for the OpenFaaS CLI

Get started: Install the CLI

You can install the CLI with a curl utility script, brew or by downloading the binary from the releases page. Once installed you'll get the faas-cli command and faas alias.

Utility script with curl:

$ curl -sSL | sudo sh

Non-root with curl (requires further actions as advised after downloading):

$ curl -sSL | sh

Via brew:

$ brew install faas-cli

Note: The brew release may not run the latest minor release but is updated regularly.

Via npm (coming soon):

$ npm install --global @openfaas/faas-cli

Note: See npm specific installation instructions and usage in the npm


To install the faas-cli on Windows go to Releases and download the latest faas-cli.exe.

Or in PowerShell:

$version = (Invoke-WebRequest "" | ConvertFrom-Json)[0].tag_name
(New-Object System.Net.WebClient).DownloadFile("$version/faas-cli.exe", "faas-cli.exe")

Build from source

The contributing guide has instructions for building from source and for configuring a Golang development environment.

Run the CLI

The main commands supported by the CLI are:

  • faas-cli new - creates a new function via a template in the current directory

  • faas-cli login - stores basic auth credentials for OpenFaaS gateway (supports multiple gateways)

  • faas-cli logout - removes basic auth credentials for a given gateway

  • faas-cli up - a combination of build/push and deploy

  • faas-cli build - builds Docker images from the supported language types

  • faas-cli push - pushes Docker images into a registry

  • faas-cli deploy - deploys the functions into a local or remote OpenFaaS gateway

  • faas-cli publish - build and push multi-arch images for CI and release artifacts

  • faas-cli remove - removes the functions from a local or remote OpenFaaS gateway

  • faas-cli invoke - invokes the functions and reads from STDIN for the body of the request

  • faas-cli store - allows browsing and deploying OpenFaaS store functions

  • faas-cli secret - manage secrets for your functions

  • faas-cli auth - (alpha) initiates an OAuth2 authorization flow to obtain a cookie

  • faas-cli registry-login - generate registry auth file in correct format by providing username and password for docker/ecr/self hosted registry

The default gateway URL of can be overridden in three places including an environmental variable.

  • 1st priority --gateway flag
  • 2nd priority --yaml / -f flag or stack.yml if in current directory
  • 3rd priority OPENFAAS_URL environmental variable

For Kubernetes users you may want to set this in your .bash_rc file:


Advanced commands:

The default template URL of can be overridden in two places including an environmental variable

  • 1st priority CLI input
  • 2nd priority OPENFAAS_TEMPLATE_URL environmental variable

Help for all of the commands supported by the CLI can be found by running:

  • faas-cli help or faas-cli [command] --help

You can chose between using a programming language template where you only need to provide a handler file, or a Docker that you can build yourself.

faas-cli auth

The auth command is currently available for alpha testing. Use the auth command to obtain a JWT to use as a Bearer token.

Two flow-types are supported in the CLI.

code grant - default

Use this flow to obtain a token.

At this time the token cannot be saved or retained in your OpenFaaS config file. You can pass the token using a CLI flag of --token=$TOKEN.


faas-cli auth \
  --auth-url \
  --audience \
  --client-id "${OAUTH_CLIENT_ID}"
client_credentials grant

Use this flow for machine to machine communication such as when you want to deploy a function to a gateway that uses OAuth2 / OIDC.


faas-cli auth \
  --grant client_credentials \
  --auth-url \
  --client-id "${OAUTH_CLIENT_ID}" \
  --client-secret "${OAUTH_CLIENT_SECRET}"\
Environment variable substitution

The CLI supports the use of envsubst-style templates. This means that you can have a single file with multiple configuration options such as for different user accounts, versions or environments.

Here is an example use-case, in your project there is an official and a development Docker Hub username/account. For the CI server images are always pushed to exampleco, but in development you may want to push to your own account such as alexellis2.

    lang: python
    handler: ./sample/url-ping
    image: ${DOCKER_USER:-exampleco}/faas-url-ping:0.2

Use the default:

$ faas-cli build
$ DOCKER_USER="" faas-cli build

Override with "alexellis2":

$ DOCKER_USER="alexellis2" faas-cli build

See also: envsubst package from Drone.

Build templates

Command: faas-cli new FUNCTION_NAME --lang python/node/go/ruby/Dockerfile/etc

In your YAML you can also specify lang: node/python/go/csharp/ruby

  • Supports common languages

  • Quick and easy - just write one file

  • Specify dependencies on Gemfile / requirements.txt or package.json etc

  • Customise the provided templates

Perhaps you need to have gcc or another dependency in your Python template? That's not a problem.

You can customise the Dockerfile or code for any of the templates. Just create a new directory and copy in the templates folder from this repository. The templates in your current working directory are always used for builds.

See also: faas-cli new --help

Third-party community templates

Templates created and maintained by a third-party can be added to your local system using the faas-cli template pull command.

Read more on community templates here.

Templates store

The template store is a great way to find official, incubator and third-party templates.

Find templates with: faas-cli template store list

Note: You can set your own custom store location with --url flag or set OPENFAAS_TEMPLATE_STORE_URL environmental variable

To pull templates from the store just write the name of the template you want faas-cli template store pull go or the repository and name faas-cli template store pull openfaas/go

To get more detail on a template just use the template store describe command and pick a template of your choice, example with go would look like this faas-cli template store describe go

Note: This feature is still in experimental stage and in the future the CLI verbs might be changed


It is possible to sign a faas-cli invoke request using a sha1 HMAC. To do this, the name of a header to hold the code during transmission should be specified using the --sign flag, and the shared secret used to hash the message should be provided through --key. E.g.

$ echo -n OpenFaaS | faas-cli invoke env --sign X-Hub-Signature --key yoursecret

Results in the following header being added:


Docker image as a function

Specify lang: Dockerfile if you want the faas-cli to execute a build or skip_build: true for pre-built images.

  • Ultimate versatility and control
  • Package anything
  • If you are using a stack file add the skip_build: true attribute
  • Use one of the samples as a basis

Read the blog post/tutorial: Turn Any CLI into a Function with OpenFaaS

faas-cli registry-login

This command allows to generate the registry auth file in the correct format in the location ./credentials/config.json

Prepare your Docker registry (if not using AWS ECR)

If you are using Dockerhub you only need to supply your --username and --password-stdin (or --password, but this leaves the password in history).

faas-cli registry-login --username <your-registry-username> --password-stdin
(then enter your password and use ctrl+d to finish input)

You could also have you password in a file, or environment variable and echo/cat this instead of entering interactively If you are using a different registry (that is not ECR) then also provide a --server as well.

Prepare your Docker registry (if using AWS ECR)

faas-cli registry-login --ecr --region <your-aws-region> --account-id <your-account-id>

Private registries

Use faas-cli in CI environments

If you're running faas-cli in a CI environment like Github Actions, CircleCI, or Travis, chances are you get the env var CI set to true.

If the CI env var is set to true or 1, faas-cli change the location of the OpenFaaS config from the default ~/.openfaas/config.yml to .openfaas/config.yml with elevated permissions for the config.yml and the shrinkwrapped build dir (if there is one).

This is really useful when running faas-cli as a container image. The recommended image type to use in a CI environment is the root variant, tagged with -root suffix. CI environments like Github Actions require you to use Docker images having a root user. Learn more about it here.

Use a YAML stack file

Read the YAML reference guide in the OpenFaaS docs.

Quick guide

A YAML stack file groups functions together and also saves on typing.

You can define individual functions or a set of them within a YAML file. This makes the CLI easier to use and means you can use this file to deploy to your OpenFaaS instance. By default the faas-cli will attempt to load stack.yaml from the current directory.

Here is an example file using the stack.yml file included in the repository.

  name: openfaas

    lang: python
    handler: ./sample/url-ping
    image: alexellis2/faas-urlping

This url-ping function is defined in the sample/url-ping folder makes use of Python. All we had to do was to write a file and then to list off any Python modules in requirements.txt.

  • Build the files in the .yml file:
$ faas-cli build

-f specifies the file or URL to download your YAML file from. The long version of the -f flag is: --yaml.

You can also download over HTTP(s):

$ faas-cli build -f

Docker along with a Python template will be used to build an image named alexellis2/faas-urlping.

  • Deploy your function

Now you can use the following command to deploy your function(s):

$ faas-cli deploy

Access functions with curl

You can initiate a HTTP POST via curl:

  • with the -d flag i.e. -d "my data here"
  • or with --data-binary @filename.txt to send a whole file including newlines
  • if you want to pass input from STDIN then use --data-binary @-
$ curl -d '{"hello": "world"}'
{ nodeVersion: 'v6.9.1', input: '{"hello": "world"}' }

$ curl --data-binary

$ uname -a | curl @-

For further instructions on the manual CLI flags (without using a YAML file) read

OpenFaaS Cloud (extensions)

OpenFaaS Cloud provides a GitOps experience for functions on Kubernetes.


  • seal

You can use the CLI to seal a secret for usage on public Git repo. The pre-requisite is that you have installed SealedSecrets and exported your public key from your cluster as pub-cert.pem.

Install kubeseal using faas-cli or the SealedSecrets docs:

$ faas-cli cloud seal --download

You can also download a specific version:

$ faas-cli cloud seal --download --download-version v0.8.0

Now grab your pub-cert.pem file from your cluster, or use the official OpenFaaS Cloud certificate.

$ kubeseal --fetch-cert --controller-name ofc-sealedsecrets-sealed-secrets > pub-cert.pem

Then seal a secret using the OpenFaaS CLI:

$ faas-cli cloud seal --name alexellis-github \
  --literal hmac-secret=1234 --cert=pub-cert.pem

You can then place the secrets.yml file in any public Git repo without others being able to read the contents.

When SealedSecrets is installed by ofc-bootstrap

The scripts/ does everything automatically.

Environment variable overrides

  • OPENFAAS_TEMPLATE_URL - to set the default URL to pull templates from
  • OPENFAAS_PREFIX - for use with faas-cli new - this can act in place of --prefix
  • OPENFAAS_URL - to override the default gateway URL
  • OPENFAAS_CONFIG - to override the location of the configuration folder, which contains auth configuration.
  • CI - to override the location of the configuration folder, when true, the configuration folder is .openfaas in the current working directory. This value is ignored if OPENFAAS_CONFIG is set.


See contributing guide.


This project is part of OpenFaaS and is licensed under the MIT License.

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