HULL plugin
The HULL plugin for Claude Code writes, validates and converts Helm charts whose Kubernetes objects are defined as data in values.
- 295 ★ on the repository
- Last commit
- Apache-2.0
Extended access
Why this level
- The server runs `helm template` and scripts on your computer.
- Import writes new chart files into the given folder.
Install
- Works in
In your terminal, with SkillFoxx CLI
npx skillfoxx add plugins/hullDetects the agents on your machine, shows the access level and pins the version.
Other ways to install
Access and checks
How we reviewExtended accessThe tool runs code or makes network calls and only reads external data.
- The server runs `helm template` and scripts on your computer.
- Import writes new chart files into the given folder.
This is third-party code. Review the repository files before installing.
What it does
HULL is a Helm library where Kubernetes objects are defined as data in `values.yaml` and the chart keeps a single template. The repository ships a Claude Code plugin: a `hull` skill with the library rules and a `hull` MCP server. The server gives the agent five tools. `hull_docs` returns documentation and recipes, `hull_schema` shows allowed fields, `hull_validate` checks a chart and reports errors as one line with a hint, `hull_render` outputs objects through `helm template` and `hull_import` converts an existing chart or manifests to HULL and verifies the result.
Who it is for. DevOps engineers maintaining charts on HULL or migrating existing Helm charts to the library with an agent's help.
Good fit when
- Chart values contain `hull.objects` and the agent needs the library rules.
- Rendering failed with `HULL failed with error` and the code must be fixed.
- An existing Helm chart must move to HULL with proof that objects are unchanged.
- You need to know which fields the schema allows for a Deployment container.
Not a fit when
- The chart uses ordinary Go templates without HULL.
- You need cluster deployment: the plugin validates and renders but does not deploy.
- You work with Kustomize or raw manifests without Helm.
Example request
Convert the chart `./charts/web` to HULL, run `hull_validate` and show that the render matches the original.Limitations
The plugin needs Python 3.8 or newer with PyYAML and jsonschema, plus `helm`. The rules are described for HULL 1.35.5, 1.36.2, 1.37.1 and later, and older versions lack some features such as image digests. For a specific library version unpack that chart and point the agent to its scripts. `hull_import` writes a chart and verifies rendering, but refactoring into idiomatic values is done in steps with repeated comparison. The last repository commit is from November 2026.
How to disable. Remove the `hull` plugin through `/plugin` or the MCP entry with `claude mcp remove hull`.
FAQ
How do I install the plugin?
With `/plugin install hull --marketplace vidispine/hull` or in two steps: `/plugin marketplace add vidispine/hull` and `/plugin install hull@vidispine-hull`.
Does the server work without Claude Code?
Yes. `hull_mcp.py` uses stdio transport and connects to any MCP client with `python3 <path>/hull_mcp.py`.
What does a validation error look like?
One line with the code, the values path, a message and a `Fix` hint. The agent reads it and corrects the exact field.
How do I convert a chart to HULL?
Run `helm template` and pass the output to `hull_import` with the same release name and namespace. The tool checks that objects match.
Are there scripts without MCP?
Yes, `hull_validate.py` and `hull_import.py` sit in `files/scripts` of the dependency with docs starting at `agents.md`.
Discussion
No questions or reviews yet.
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README in short
The README has a section on working with agents and migrating charts, linking the agent guide, cookbook and a tools document. The repository doubles as a Claude Code plugin marketplace.