Kamal

aid: kamal-deploy
name: Kamal
description: >-
  Kamal is an open-source deployment tool from 37signals (DHH / Basecamp) for
  deploying containerized web applications to any infrastructure — bare metal,
  cloud VMs, or a mix — with zero-downtime rolling restarts. Originally built
  for Rails apps, Kamal works with any web application that can be packaged as
  a Docker container. It uses SSHKit to drive remote commands over SSH and
  pairs with kamal-proxy, a lightweight HTTP proxy written in Go that
  seamlessly switches request traffic between old and new containers during a
  deploy. Kamal is imperative and Capistrano-like in feel, with a single
  `config/deploy.yml` describing servers, image, registry, accessories, env,
  secrets, and proxy/SSL settings. Capabilities include auto-provisioning
  Docker on new servers, remote builds, asset bridging, accessory services
  (databases, Redis, cron sidecars), automatic TLS via Let's Encrypt, host-
  and path-based routing, and hooks for custom pre/post-deploy logic. Kamal is
  the operational backbone of 37signals' on-premises exit from major cloud
  providers and powers their ONCE product line. Kamal itself is a CLI tool,
  not a hosted service — there is no public REST API, no SDK, and no paid
  tier. The project is released under the MIT License and developed openly on
  GitHub under the `basecamp` organization.
type: Index
position: Producer
access: 3rd-Party
image: https://kinlane-productions.s3.amazonaws.com/apis-json/apis-json-logo.jpg
tags:
  - Deployment
  - DevOps
  - Docker
  - Containers
  - Zero Downtime
  - Rolling Deploys
  - Rails
  - Ruby
  - Open Source
  - 37signals
  - Basecamp
  - On Premises
  - Infrastructure
  - CLI
  - SSH
url: https://raw.githubusercontent.com/api-evangelist/kamal-deploy/refs/heads/main/apis.yml
created: '2026-05-25'
modified: '2026-05-25'
specificationVersion: '0.20'
apis:
  - aid: kamal-deploy:kamal
    name: Kamal CLI
    description: >-
      The Kamal CLI (`kamal`) is the primary command-line interface for
      packaging, shipping, and operating containerized web apps across one or
      more SSH-reachable servers. It reads `config/deploy.yml` (plus
      environment-specific overlays and encrypted secrets) and orchestrates
      the full lifecycle: building images, pushing to a registry, provisioning
      Docker on target hosts, starting accessory services, deploying the app
      via kamal-proxy with health-check gated traffic switching, and tailing
      logs or rolling back to a prior version. Command groups include `app`,
      `accessory`, `build`, `proxy`, `registry`, `secrets`, `server`, and
      `prune`, plus top-level shortcuts like `deploy`, `redeploy`, `rollback`,
      `setup`, `audit`, `details`, `env`, `lock`, `version`, and `init`.
    humanURL: https://kamal-deploy.org/docs/
    tags:
      - CLI
      - Deployment
      - Docker
      - Rails
      - Ruby
      - SSH
    properties:
      - type: Documentation
        url: https://kamal-deploy.org/docs/
      - type: GettingStarted
        url: https://kamal-deploy.org/docs/installation/
      - type: Source
        url: https://github.com/basecamp/kamal
      - type: GitHubRepository
        url: https://github.com/basecamp/kamal
      - type: License
        url: https://github.com/basecamp/kamal/blob/main/MIT-LICENSE
      - type: ReleaseNotes
        url: https://github.com/basecamp/kamal/releases
      - type: Configuration
        url: https://kamal-deploy.org/docs/configuration/
        title: deploy.yml Configuration Reference
      - type: Hooks
        url: https://kamal-deploy.org/docs/hooks/
      - type: Upgrade
        url: https://kamal-deploy.org/docs/upgrading/
      - type: SDK
        url: https://rubygems.org/gems/kamal
        title: kamal (RubyGem)
  - aid: kamal-deploy:kamal-proxy
    name: Kamal Proxy
    description: >-
      Kamal Proxy is a minimal HTTP reverse proxy written in Go that powers
      the zero-downtime deploy switchover behind Kamal. It exposes a small
      `kamal-proxy` CLI with `run`, `deploy`, and `remove` commands; the
      Kamal CLI talks to it over SSH to register new container instances
      (`hostname:port`), runs health checks (default `GET /up` once per second
      returning `200`), drains traffic from old instances, and atomically
      switches new traffic to the healthy instance. The proxy supports
      host-based routing (multiple apps on one server), path-based routing
      with optional prefix stripping, custom health-check paths/ports/timeouts,
      automatic TLS via Let's Encrypt, and custom TLS certificate/key files
      (useful for Cloudflare origin certs or private CAs). It can also be run
      standalone outside of Kamal.
    humanURL: https://github.com/basecamp/kamal-proxy
    tags:
      - Proxy
      - HTTP
      - Load Balancing
      - Zero Downtime
      - TLS
      - Go
    properties:
      - type: Documentation
        url: https://github.com/basecamp/kamal-proxy/blob/main/README.md
      - type: Source
        url: https://github.com/basecamp/kamal-proxy
      - type: GitHubRepository
        url: https://github.com/basecamp/kamal-proxy
      - type: License
        url: https://github.com/basecamp/kamal-proxy/blob/main/MIT-LICENSE
      - type: Dockerfile
        url: https://github.com/basecamp/kamal-proxy/blob/main/Dockerfile
common:
  - type: Website
    url: https://kamal-deploy.org
  - type: Documentation
    url: https://kamal-deploy.org/docs/
  - type: GettingStarted
    url: https://kamal-deploy.org/docs/installation/
  - type: Source
    url: https://github.com/basecamp/kamal
  - type: GitHubRepository
    url: https://github.com/basecamp/kamal
  - type: GitHubOrganization
    url: https://github.com/basecamp
  - type: License
    url: https://github.com/basecamp/kamal/blob/main/MIT-LICENSE
    title: MIT License
  - type: ReleaseNotes
    url: https://github.com/basecamp/kamal/releases
  - type: ChangeLog
    url: https://github.com/basecamp/kamal/releases
  - type: Community
    url: https://github.com/basecamp/kamal/discussions
    title: GitHub Discussions
  - type: Community
    url: https://discord.gg/YgHVT7GCXS
    title: Discord
  - type: Contributing
    url: https://github.com/basecamp/kamal/blob/main/CONTRIBUTING.md
  - type: CodeOfConduct
    url: https://github.com/basecamp/kamal/blob/main/CODE_OF_CONDUCT.md
  - type: SDK
    url: https://rubygems.org/gems/kamal
    title: kamal (RubyGem)
  - type: CLI
    url: https://kamal-deploy.org/docs/commands/
    title: kamal CLI
  - type: Integrations
    url: https://github.com/basecamp/kamal-proxy
    title: kamal-proxy (Go)
  - type: Integrations
    url: https://github.com/basecamp/kamal-skiff
    title: kamal-skiff — static sites on nginx + SSI via Kamal
  - type: Integrations
    url: https://github.com/basecamp/kamal-site
    title: kamal-site — source for kamal-deploy.org
  - type: UseCases
    url: https://once.com
    title: 37signals ONCE — single-tenant self-hosted apps deployed via Kamal
maintainers:
  - FN: Kin Lane
    email: [email protected]