hanko

hanko

Validate Claude Code plugin manifests before you submit them.

hanko is a single-binary Go CLI that reads your .claude-plugin/plugin.json and .claude-plugin/marketplace.json, validates them against the schema extracted from Anthropic's plugin docs, and catches the common footguns that make marketplace submission fail: reserved marketplace names, duplicate hooks declarations, agents set to a bare directory string, path traversal, and more.

The name: 判子 (hanko) is the personal seal stamped on official Japanese documents, the traditional act of approving a submission. Run hanko check before you file yours.

Install

curl -fsSL https://roninforge.org/hanko/install.sh | sh

Or grab a binary from the latest release. Prefer Go install:

go install github.com/RoninForge/hanko/cmd/hanko@latest

Quickstart

# From inside a plugin repo:
hanko check

# Before submitting to a specific marketplace:
hanko submit-check --marketplace anthropic

# Print the embedded JSON Schema for editor integration:
hanko schema print --file plugin > .claude-plugin/plugin.schema.json

# Use in CI (JSON output):
hanko check --json .

What it catches

• Schema errors the official validator reports opaquely (missing name, wrong types, non-kebab-case, invalid hook event names).
• Reserved marketplace names (eight exact names plus an impersonation-pattern regex).
• Duplicate hooks declaration where a plugin points hooks at ./hooks/hooks.json even though Claude Code v2.1+ auto-loads that path by convention.
• agents as a bare directory string, which the validator rejects despite the docs example showing it works.
• Path traversal (.. or absolute) in any component path.
• Missing author for plugins that plan to ship via the Anthropic marketplace (Claude Desktop's listAvailablePlugins validator refuses to load the whole catalog when even one plugin lacks one).
• Missing version, which is technically optional but breaks Claude Code's install cache.

See docs/rules.md for the full list with fix suggestions.

Marketplaces

hanko submit-check layers rules on top of the base schema per marketplace:

GitHub Action

- uses: RoninForge/hanko@v0
  with:
    path: .
    marketplace: anthropic

Appends a findings table to the workflow run summary (the "Summary" tab of the PR's checks view) and exits non-zero on any error-severity finding. Set fail-on-warnings: true to also fail on warnings.

How it works

1. //go:embed includes the JSON Schema for plugin.json and marketplace.json.
2. santhosh-tekuri/jsonschema/v6 validates the file against the schema.
3. Go-coded rules apply the checks that do not round-trip cleanly through JSON Schema (reserved names, duplicate hooks, cross-references).
4. Errors are formatted with schema path, offending value, a one-line fix suggestion, and a doc link.

Zero network calls. Binary is roughly 6 MB. MIT licensed.

Development

See CONTRIBUTING.md.

Security

See SECURITY.md.