aid: nixpacks
name: Nixpacks
description: >-
  Nixpacks is an open-source build tool that converts application source code
  into OCI-compliant Docker images by combining language-specific providers,
  Nix packages, and Buildkit. Originally created by Railway as the build system
  powering the Railway platform, Nixpacks inspects a project's source, selects
  one or more providers (Node, Python, Ruby, Go, Java, Rust, PHP, Elixir,
  Deno, Crystal, .NET, Swift, Scala, Dart, Haskell, Gleam, Zig, Clojure,
  Lunatic, Cobol, Scheme, F#, Staticfile, and more), and produces a reproducible
  build plan composed of setup, install, build, and start phases. The plan
  declares Nix packages, apt packages, environment variables, commands, and
  cache directories, and can be customized via a `nixpacks.toml` file, CLI
  flags, or environment variables. Compared with Cloud Native Buildpacks,
  Nixpacks uses Nix as its package layer, ships as a single Rust CLI, and
  outputs a plain Dockerfile/OCI image without requiring a buildpack
  lifecycle. The project is MIT licensed and currently in maintenance mode;
  Railway recommends Railpack as the actively developed successor.
url: https://raw.githubusercontent.com/api-evangelist/nixpacks/refs/heads/main/apis.yml
image: https://kinlane-productions.s3.amazonaws.com/apis-json/apis-json-logo.jpg
type: Index
position: Consuming
access: 3rd-Party
tags:
  - Build Tool
  - Buildpacks
  - Docker
  - OCI
  - Nix
  - Nixpkgs
  - Container Image
  - Application Packaging
  - Railway
  - Open Source
  - Rust
  - DevOps
  - Platform Engineering
  - PaaS
created: '2026-05-24'
modified: '2026-05-24'
specificationVersion: '0.20'
apis:
  - aid: nixpacks:cli
    name: Nixpacks CLI
    description: >-
      The Nixpacks command-line interface is the primary interface for
      generating build plans and producing Docker images from application
      source. Core commands include `nixpacks plan` (emit the JSON build
      plan that would be used), `nixpacks build` (produce an OCI image via
      Docker BuildKit), and `nixpacks detect` (identify which providers
      match the source directory). The CLI accepts inline overrides for
      install, build, and start commands, Nix and apt packages, environment
      variables, the base build image, and a separate runtime image, and is
      distributed as a single Rust binary via Homebrew, install script,
      Docker image, and GitHub releases.
    humanURL: https://nixpacks.com/docs/cli
    tags:
      - CLI
      - Build
      - Plan
      - Detect
    properties:
      - type: Documentation
        url: https://nixpacks.com/docs/cli
      - type: GettingStarted
        url: https://nixpacks.com/docs/getting-started
      - type: SourceCode
        url: https://github.com/railwayapp/nixpacks
      - type: Install
        url: https://nixpacks.com/docs/install
  - aid: nixpacks:build-plan
    name: Nixpacks Build Plan
    description: >-
      The Nixpacks build plan is the JSON representation of how a source
      directory will be turned into a container image. A plan declares the
      list of providers used, top-level `variables`, `staticAssets`,
      `buildImage`, and an ordered set of phases (`setup`, `install`,
      `build`, plus any provider- or user-defined phases) along with a
      `start` phase. Each phase carries `cmds`, `nixPkgs`, `nixLibs`,
      `nixOverlays`, `nixpkgsArchive`, `aptPkgs`, `dependsOn`,
      `cacheDirectories`, `onlyIncludeFiles`, and `paths`. Plans can be
      saved and replayed via `nixpacks build --plan plan.json` to guarantee
      reproducible image builds.
    humanURL: https://nixpacks.com/docs/how-it-works
    tags:
      - Build Plan
      - JSON
      - Phases
      - Reproducible Builds
    properties:
      - type: Documentation
        url: https://nixpacks.com/docs/how-it-works
      - type: Reference
        url: https://nixpacks.com/docs/configuration/file
  - aid: nixpacks:configuration-file
    name: Nixpacks Configuration File (nixpacks.toml)
    description: >-
      Projects can override or extend the auto-detected build plan by
      committing a `nixpacks.toml` (or `nixpacks.json`) file at the root of
      the repository. The configuration file mirrors the build-plan
      structure with top-level `providers`, `buildImage`, `variables`, and
      `staticAssets`, a `[phases.<name>]` table for each phase carrying
      `cmds`, `nixPkgs`, `nixLibs`, `aptPkgs`, `dependsOn`,
      `cacheDirectories`, `onlyIncludeFiles`, and `paths`, and a `[start]`
      table for `cmd`, `runImage`, and runtime-only file inclusion. The
      `"..."` token can be used inside array fields to extend rather than
      replace provider-supplied values.
    humanURL: https://nixpacks.com/docs/configuration/file
    tags:
      - Configuration
      - TOML
      - Phases
      - Customization
    properties:
      - type: Documentation
        url: https://nixpacks.com/docs/configuration/file
      - type: Reference
        url: https://nixpacks.com/docs/configuration/environment
  - aid: nixpacks:providers
    name: Nixpacks Language Providers
    description: >-
      Providers are the pluggable modules that detect a language or
      framework in the source directory and contribute their portion of the
      build plan. Nixpacks ships with providers for Node (npm, pnpm, Yarn,
      Bun), Python (pip, Poetry, PDM, uv), Ruby, Go, Java (Gradle, Maven),
      Rust, PHP, Elixir, Deno, Crystal, C#/.NET, Swift, Scala, Dart,
      Haskell, Gleam, Zig, Clojure, Lunatic, Cobol, Scheme, F#, and a
      Staticfile provider for purely static sites. Each provider declares
      the Nix packages, install commands, build commands, and default start
      command appropriate to its ecosystem; multiple providers can compose
      in a single image (for example, a Node frontend with a Python
      backend).
    humanURL: https://nixpacks.com/docs/providers
    tags:
      - Providers
      - Detection
      - Languages
      - Frameworks
    properties:
      - type: Documentation
        url: https://nixpacks.com/docs/providers
      - type: SourceCode
        url: https://github.com/railwayapp/nixpacks/tree/main/src/providers
  - aid: nixpacks:github-action
    name: Nixpacks GitHub Action
    description: >-
      The official `iloveitaly/github-action-nixpacks` GitHub Action wraps
      the Nixpacks CLI so that CI pipelines can build and optionally push
      OCI images directly from a workflow without installing Nixpacks
      manually. The action accepts the same overrides as the CLI (image
      tags, platform, push target, plan path, environment variables) and is
      commonly paired with Docker login actions to publish images to
      GitHub Container Registry, Docker Hub, or any OCI-compliant registry.
    humanURL: https://github.com/iloveitaly/github-action-nixpacks
    tags:
      - GitHub Actions
      - CI/CD
      - Build
      - Container Image
    properties:
      - type: SourceCode
        url: https://github.com/iloveitaly/github-action-nixpacks
      - type: Documentation
        url: https://nixpacks.com/docs/guides/github-actions
common:
  - type: Website
    name: Nixpacks Website
    description: Official Nixpacks marketing and documentation site.
    url: https://nixpacks.com
  - type: Documentation
    name: Nixpacks Documentation
    description: Full Nixpacks documentation covering install, CLI, providers, configuration, and how it works.
    url: https://nixpacks.com/docs
  - type: GettingStarted
    name: Nixpacks Getting Started
    description: Quickstart for installing Nixpacks and building your first image from a source directory.
    url: https://nixpacks.com/docs/getting-started
  - type: Install
    name: Nixpacks Install Guide
    description: Installation instructions across Homebrew, the install script, Docker image, and GitHub release binaries.
    url: https://nixpacks.com/docs/install
  - type: GitHubOrganization
    name: Railway GitHub Organization
    description: GitHub organization that owns Nixpacks and the broader Railway open-source ecosystem.
    url: https://github.com/railwayapp
  - type: GitHubRepository
    name: Nixpacks GitHub Repository
    description: Primary source repository for the Nixpacks Rust CLI, language providers, and tests.
    url: https://github.com/railwayapp/nixpacks
  - type: SourceCode
    name: Nixpacks Source
    description: Rust source code for the Nixpacks CLI, build planner, and language providers.
    url: https://github.com/railwayapp/nixpacks
  - type: License
    name: MIT License
    description: Nixpacks is distributed under the MIT License.
    url: https://github.com/railwayapp/nixpacks/blob/main/LICENSE
  - type: Issues
    name: Nixpacks Issues
    description: GitHub issue tracker for Nixpacks bug reports and feature requests.
    url: https://github.com/railwayapp/nixpacks/issues
  - type: ChangeLog
    name: Nixpacks Releases
    description: Release notes and version history for the Nixpacks CLI.
    url: https://github.com/railwayapp/nixpacks/releases
  - type: ContainerImage
    name: Nixpacks Docker Image
    description: Official Docker image for running Nixpacks in CI and other containerized environments.
    url: https://github.com/railwayapp/nixpacks/pkgs/container/nixpacks
  - type: Provider
    name: Railway
    description: Railway, the PaaS that originated Nixpacks and uses it to build user applications.
    url: https://railway.app
  - type: Successor
    name: Railpack
    description: Railpack, Railway's actively developed successor to Nixpacks.
    url: https://github.com/railwayapp/railpack
  - type: Twitter
    name: Railway on Twitter/X
    description: Railway's social account, the primary public channel for Nixpacks announcements.
    url: https://twitter.com/Railway
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com