Dagger

Dagger is an open-source platform for automating software delivery, built by Dagger, Inc. and licensed under Apache 2.0. It lets engineers build, test, and deploy any codebase using a programmable, container-native runtime that runs identically on a developer's laptop, a CI server, or cloud infrastructure. The project is actively maintained on GitHub with over 15,900 stars and regular commits as of mid-2026.

What It Is

Dagger is a software delivery automation engine that replaces shell scripts and proprietary YAML-based CI configurations with a typed, programmable API. At its core, Dagger provides a cross-language system API for orchestrating containers, filesystems, secrets, git repositories, and network tunnels. Engineers write delivery pipelines in their language of choice — Go, Python, TypeScript, PHP, Java, .NET, Elixir, or Rust — using native SDKs generated from the API schema, giving full type safety and editor support. The runtime executes these pipelines in sandboxed, containerized functions, making behavior consistent across every environment.

Architecture and Core Design

Dagger's design centers on four principles the project describes as programmable, local-first, repeatable, and observable:

• Programmable: A complete execution engine and system API with SDKs for 8 languages, an interactive REPL, and a module ecosystem on Daggerverse.
• Local-first: The only runtime dependency is a Linux container runtime (Docker or compatible). Pipelines run identically on macOS and Windows via Docker Desktop.
• Repeatable: Every operation is keyed by its inputs and cached by default. Content-addressed caching works automatically across local runs and CI, so only affected operations re-run when inputs change.
• Observable: Every operation emits OpenTelemetry spans. The CLI includes a live terminal UI (TUI); traces can be exported to Jaeger, Honeycomb, or any OTel-compatible backend.

Module System and Typed Artifacts

Dagger supports custom object types with encapsulated state and functions. Types are content-addressed and can be passed across SDK language boundaries and module boundaries without serialization. The Daggerverse is the public registry for reusable Dagger modules, enabling teams to share and compose pipeline components. This module system is what the project positions as the replacement for copy-pasted YAML snippets and fragile shell scripts.

Deployment Model

Dagger runs as a local CLI tool installed via Homebrew (brew install dagger/tap/dagger) or other package managers. It connects to any local container runtime and can also be pointed at remote cloud infrastructure. Dagger Cloud is a companion SaaS product that adds a web-based trace visualization, centralized caching, and team-level observability on top of the open-source engine. The open-source core and the Cloud product are separate offerings.

Open-Source Status and Community

The core Dagger engine is published under the Apache License 2.0 at github.com/dagger/dagger. The repository had 15,935 stars and 886 forks as of June 2026, with 116 open issues and active daily pushes. Community channels include a Discord server (discord.gg/dagger-io) and GitHub Discussions. The project also runs community programs including Dagger Commanders and Engineering Deep Dives.