AI
Project Growth and a New PR Review Process
Backstage now has over 4,000 adopters, 255 open source plugins, and 32,900 GitHub stars. The community plugins repository holds 190-plus plugin packages across roughly 100 workspaces, maintained by 85 contributors. Two new core maintainers, Andre and Ramis, cover five project areas between them. The team also replaced randomized PR assignment with a prioritized queue: each pull request scores on size, CI checks, and Copilot approval, and a community reviewer approval bumps a PR’s priority without requiring full repo access.
Front-End System Reaches 1.0 Release Candidate
The new front-end system is now the default for new Backstage apps. The release shipped last week is the 1.0 release candidate. Key additions include subpages as configurable extensions, built-in permission and feature flag support, and a new compact plugin header roughly half the size of the old one. Three agent skills launched this week covering app migration and two plugin migration paths. Support for the old front-end system will last until end of 2026, with some features shipping only in the new system starting sooner.
CLI Authentication and MCP Integration
Static tokens were the old workaround for authenticating CLIs against Backstage backends. They are long-lived and hard to manage. Client identity metadata documents (CIMD) replace dynamic client registration and ship a standard OAuth flow that both the CLI and MCP clients reuse. Tokens previously expired after one hour. Offline access scopes and refresh tokens now let sessions continue without user interruption. Claude implemented CIMD support this week, bringing client adoption in line with the spec.
Actions Registry: CLI and MCP Demo
The actions registry exposes plugin actions over HTTP so any client, CLI or MCP server, can call them directly. New catalog actions include query catalog entities using entity predicates, add and remove location, validate entities against raw YAML, and a “who am I” action. The live demo showed the CLI login command opening an approval flow, then Claude calling “who am I” followed by “query catalog entities” to return all components owned by Ben Lambert and his platform team group. The scaffolder CLI is now roughly 80% of the way to an MVP.
CLI Modularization
The monolithic Backstage CLI split into separate modules in the latest release. Each module carries its own commands, linting, migrations, config management, and can run standalone via npx. End users no longer install the full CLI to run auth or action commands. Lazy-loading each module’s implementation keeps startup fast by avoiding the full dependency tree at runtime. The roadmap adds replacing ESLint with oxlint and swapping in Vitest. Core maintainer Aramis drove most of this work.
Catalog Model Extensions and the AI Context Kind
The catalog schema today is a black box. Plugin annotations like the Kubernetes label selector carry no machine-readable description, making them hard for humans and LLMs to interpret. A new catalog model extension API, targeting release 1.50, lets plugins declare annotations, custom fields, and new kinds along with JSON schema, descriptions, and examples. The scaffolder plugin will register the template kind automatically on install. A new AI context kind, merged two hours before the talk, stores skills in the catalog for governance and discoverability, with prompts planned as a follow-on.
Notable Quotes
the more an engineer uses AI tools, the more they also use the backstage UI, which indicates that AI does not replace the UI Patrik Oldsberg · ▶ 22:47
you’re not just adding data anymore. You’re adding or defining how that data connects and behaves with the catalog model. Ben Lambert · ▶ 28:37
it’s closely related to model extensions. Uh but it’s all about providing additional context to AI Patrik Oldsberg · ▶ 29:16
Key Takeaways
- The front-end system hits 1.0 RC; old system support ends by late 2026.
- CIMD replaces static tokens, giving CLI and MCP clients a standard OAuth flow.
- Catalog model extensions will make plugin annotations machine-readable for LLMs by release 1.50.
About the Speaker(s)
Patrik Oldsberg is a Senior Software Engineer at Spotify and a core maintainer of Backstage. He joined Spotify’s platform organization in 2019 and helped bring Backstage into the open source.
Ben Lambert is a Senior Engineer at Spotify and a core maintainer of Backstage.