Argo CD

Argo CD is a declarative GitOps continuous delivery tool for Kubernetes. It runs as a set of controllers and services inside a cluster, watches one or more Git repositories that describe the desired state of applications, and reconciles those declarations into the live cluster. The repository at argoproj/argo-cd contains all the binaries that make up the Argo CD distribution: the API server, the application controller, the repo server, the ApplicationSet controller, the commit server, the CMP plugin server, the notifications controller, helper binaries, and the React/TypeScript web UI.

What this wiki covers

Argo CD is a large, multi-binary monorepo. This wiki gives engineers a working map of the codebase and the systems behind the public docs at https://argo-cd.readthedocs.io/.

• Architecture — the binaries, processes, and data flows that make up Argo CD.
• Getting started — how to build, run, and test the project locally.
• Glossary — the project's domain vocabulary (Application, Project, Sync, Hydrator, etc.).
• Applications — every binary the repo produces.
• Features — cross-cutting capabilities like sync, RBAC, ApplicationSets, notifications, and the manifest hydrator.
• Primitives — the CRDs (Application, AppProject, ApplicationSet) and core domain objects.
• API — the gRPC + REST API exposed by argocd-server.
• Reference — configuration, data models, and dependencies.

Where the code lives

Argo CD is primarily a Go project (980 Go files) with a React/TypeScript frontend (210 .ts/.tsx files). The major directories are:

Path	What it contains
cmd/	All binaries. A single Go main.go dispatches to subcommand packages based on os.Args[0].
controller/	The application controller — the core reconciliation loop.
server/	The argocd-server API service, with one subdirectory per gRPC service group.
reposerver/	The repo server that renders manifests from Git/Helm/OCI sources.
applicationset/	The ApplicationSet controller, generators, and template engine.
commitserver/	The commit server used by the manifest hydrator.
cmpserver/	Config Management Plugin gRPC server.
pkg/apis/application/v1alpha1/	CRD types (Application, AppProject, ApplicationSet, Repository, …).
util/	Shared libraries (git, helm, kustomize, oidc, rbac, cache, settings, …).
ui/	React/TypeScript single-page web UI.
manifests/	Kustomize bases that produce the install YAML and Helm-equivalent layouts.
docs/	The MkDocs source for https://argo-cd.readthedocs.io/.

Project status

Argo CD is a CNCF Graduated project, actively maintained by Akuity, Intuit, Red Hat, and other contributors listed in MAINTAINERS.md. It has been under development since February 2018 and has accumulated more than 10,000 commits across hundreds of contributors. The current major version is v3 (go.mod declares module github.com/argoproj/argo-cd/v3).

For contribution rules and PR conventions enforced on the upstream repository, see the strict guidelines in AGENTS.md at the repo root.