Getting Started

This guide walks you through creating, developing, and deploying your first function with FnKit.

Prerequisites

  • Docker installed and running
  • Git installed
  • fnkit installed
  • A runtime installed for your language of choice (e.g., Node.js, Python, Go)

Check everything is ready:

fnkit doctor

1. Create a Function 

fnkit node my-api
cd my-api

This creates a new directory with:

  • A function source file with a hello world handler
  • A Dockerfile for containerised deployment
  • A docker-compose.yml for gateway integration
  • A .gitignore tailored to the runtime
  • Dependencies installed (e.g., node_modules/)

You can use any supported runtime — just swap node for python, go, java, ruby, dotnet, php, dart, or cpp.

With a Git Remote 

fnkit node my-api --remote git@github.com:user/my-api.git

Using the Explicit Form 

fnkit new node my-api

2. Develop Locally 

fnkit dev

Your function starts on http://localhost:8080. Edit the source file and restart to see changes.

Options 

fnkit dev --port 3000           # Custom port
fnkit dev --target myFunction   # Specific function target

3. Set Up the Platform

Before deploying, you need the infrastructure running on your server. This is a one-time setup.

Create the Docker Network 

docker network create fnkit-network

Start the API Gateway 

fnkit gateway init
fnkit gateway build
fnkit gateway start --token your-secret-token

The gateway runs on port 8080 and authenticates requests with a Bearer token. See Gateway docs for details.

(Optional) Start the Shared Cache 

fnkit cache init
fnkit cache start

All functions can now access a Redis-compatible cache at redis://fnkit-cache:6379. See Cache docs.

(Optional) Set Up HTTPS 

fnkit proxy init
fnkit proxy add api.example.com
cd fnkit-proxy && docker compose up -d

Caddy handles TLS certificates automatically via Let’s Encrypt. See Proxy docs.

4. Deploy 

fnkit deploy remote --host root@your-server

This SSHs to your server, creates a bare git repo with a deploy hook, and adds a deploy git remote locally. No Forgejo or GitHub Actions needed.

Push to Deploy 

git add . && git commit -m "init" && git push deploy main

The post-receive hook will:

  1. Build a Docker image from your Dockerfile
  2. Deploy the container to fnkit-network
  3. Run a health check
  4. Auto-rollback on failure

Or Use Forgejo/GitHub Actions 

fnkit deploy setup

This interactive wizard generates a deploy workflow for Forgejo (default) or GitHub Actions.

Verify 

fnkit deploy status

Call Your Function 

# Through the gateway
curl -H "Authorization: Bearer your-secret-token" http://localhost:8080/my-api

# With a custom domain (if proxy is set up)
curl https://api.example.com/my-api

What’s Next?

  • Runtimes — Explore all 12 supported runtimes
  • Gateway — Set up orchestrator pipelines for multi-function workflows
  • Cache — Add caching to your functions
  • Deploy — Configure Forgejo or GitHub Actions in detail
  • MQTT — Build event-driven functions with MQTT
  • Production — Full server setup guide

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