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.
Kamal publishes 2 APIs on the APIs.io network. Tagged areas include Deployment, DevOps, Docker, Containers, and Zero Downtime.
Kamal’s developer surface includes documentation, getting-started guide, release notes, changelog, CLI, and 12 more developer resources.
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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 `c...
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`...
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
deliveryModel:
model: self-hosted
license: MIT
license_evidence:
repo: basecamp/kamal
spdx: MIT
stars: 14604
open_source: true
commercial: false
callable_host: false
label: Self-hosted open source · you run it yourself
confidence: medium
source:
- repository-license
generated: '2026-09-25'
method: derived
accessModel:
pricing: unknown
onboarding: unknown
trial: false
try_now: false
public: false
label: Unknown
confidence: low
source: []
generated: '2026-07-22'
method: derived
position: Producing
access: 3rd-Party
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/kamal-deploy.png
tags:
- Deployment
- DevOps
- Docker
- Containers
- Zero Downtime
- Rolling Deploys
- Rails
- Ruby
- Open Source
- 37signals
- Basecamp
- On-Premises
- Infrastructure
- CLI
- SSH
tags_raw:
- Deployment
- DevOps
- Docker
- Containers
- Zero Downtime
- Rolling Deploys
- Rails
- Ruby
- Open Source
- 37signals
- Basecamp
- On Premises
- Infrastructure
- CLI
- SSH
- Open-Source
url: https://raw.githubusercontent.com/api-evangelist/kamal-deploy/refs/heads/main/apis.yml
created: '2026-05-25'
modified: '2026-05-25'
specificationVersion: '0.23'
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
tags_raw:
- 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: SDKs
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: IssueTracker
url: https://github.com/basecamp/kamal/issues
- type: DomainSecurity
url: security/kamal-deploy-domain-security.yml
- 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: SDKs
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: kin@apievangelist.com
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