The platform · An internal developer platform, from the inside
One platform, built to be easy to live with
Hangar is the internal developer platform I've always wanted to work on. Under the hood it's a Crossplane control plane, GitOps delivery through ArgoCD, Tower on Backstage as the place people actually look, and Glidepath for CI/CD. It looks after two kinds of work, container apps and AI agents, through the same API and under the same rules.
No cluster ever holds credentials for another cluster's API. The only thing that crosses a boundary is a reviewed, merged commit.
That rule came out of Glidepath's multi-cluster work, was verified live twice, and every later design carries it forward rather than reopening it. Backstage holds no Kubernetes credentials at all; even creating a new service is a commit. Outcomes come back as events, never as an API call reaching the other way.
Four layers
Crossplane and Airframe
The platform's API. XRDs define what a compliant service is; Compositions and Functions make it real, and watch it afterwards.
Glidepath and ArgoCD
Tekton pipelines chained by events, promotion by pull request, one ArgoCD per cluster as the only writer.
Tower on Backstage
Self-service, release orchestration and operations in one place, with every change made as a GitOps PR.
Apron clusters
Every cluster starts from the same template and the same bootstrap order, with its own trust roots.
Two kinds of workload, one platform
An AI agent gets the same treatment as a service, with less authority by default.
| Container apps | AI agent workloads | |
|---|---|---|
| Defined by | An Airframe claim (app stack, environments, components) in git | An agent definition, schema-validated, in git |
| Created by | A reviewed commit, usually opened from Tower | A reviewed commit for the definition; a scoped claim for each run |
| Runs on | Its own namespaces per environment, on every cluster it is promoted to | A sandbox in one reserved namespace, on dev clusters only |
| Identity | Kubernetes service accounts, verified by TokenReview | The same, plus a scoped token per call from Clearance |
| Changes the platform by | Pull requests to its GitOps repo, synced by ArgoCD | Pull requests, through the same gates plus two for agents |
| Observed through | OTel traces, DORA metrics, SLOs in Tower | The same telemetry, plus a hash-chained flight recorder |
The products
HangarHome base for building, releasing, and watching every service you run.
The platform as a whole: design, docs and the running status.
AirframeThe structural core: what a compliant service is, defined once.
Crossplane XRDs, Compositions and Functions, and the one application chart every tier deploys through.
GlidepathThe guarded descent from a merged commit to a verified release.
CI/CD on Tekton and Pipelines-as-Code, chained by CDEvents, released by GitOps.
TowerRelease orchestration and operational intelligence for Backstage.
The single pane of glass: releases, deployments, SLOs and fleet views.
ApronGround infrastructure a cluster needs before a Hangar can run on it.
The template for a new cluster repo: one config file, one script, a known bootstrap order.
AutopilotAny AI agent workload, bounded and audited.
Clearance (policy, audit, sessions), agent definitions, Preflight evaluations and the AgentRun claim.