Concourse CI is a free, open-source, container-based CI/CD automation tool with declarative YAML pipelines. Self-hosted, written in Go under Apache 2.0.
Concourse CI is a free, open-source automation system focused on CI/CD, originally built in 2014 by engineers on Pivotal's Cloud Foundry team who were dissatisfied with Jenkins' plugin-driven, UI-configured pipelines. It was open sourced in 2015 and remains fully community- and sponsor-supported, with no paid tier or official hosted service.
The project treats pipelines as first-class, version-controlled artifacts defined in declarative YAML rather than assembled through a web UI. Every build step runs inside an isolated container, giving Concourse strong guarantees around reproducibility and idempotency that distinguish it from more traditional, stateful CI servers.
Pipelines are built from three primitives: resources (versioned inputs and outputs like Git repositories or container images), tasks (containerized units of work), and jobs (sequences of tasks triggered by resource changes). This model lets Concourse express complex, multi-stage delivery workflows without a plugin marketplace — new integrations are just container images implementing a simple resource interface.
The fly CLI lets developers run a task locally with uncommitted changes before pushing, shortening the feedback loop, while the web UI visualizes pipelines as a graph for tracing failures back to their source. Concourse can be installed as a standalone binary, via Docker Compose, through a Kubernetes Helm chart, or as a BOSH release, with PostgreSQL as the backing database.
Concourse CI is entirely free and open source under the Apache 2.0 license — there are no paid plans, seat limits, or usage caps imposed by the project itself. The only real cost is the infrastructure a team provisions to run the web, worker, and PostgreSQL nodes.
Because there is no official managed SaaS offering, organizations that don't want to operate their own Concourse deployment typically look to hosted CI alternatives instead; Concourse is aimed squarely at teams willing to self-host in exchange for full control over their pipeline infrastructure.
Yes. Concourse is fully open source under the Apache 2.0 license with no paid tiers; you only pay for the infrastructure you run it on.
No official managed SaaS exists. Concourse is designed to be self-hosted using a standalone binary, Docker Compose, a Helm chart, or a BOSH release.
The core web component (ATC) and workers are written in Go, while the browser-based dashboard UI is built with Elm.
Concourse uses declarative, version-controlled pipeline YAML and fully containerized task execution instead of Jenkins' UI-configured jobs and plugin ecosystem.
Yes, the fly CLI's execute command runs a task locally with your uncommitted changes, letting you debug before committing.