plugins

This repo is a Claude Code plugin marketplace. Today it ships one plugin — dtwo — which bundles the DTwo MCP server connection and the gateway/policy/Rego skills for managing DTwo gateways.

If you're a customer looking to install or use the plugin, jump to dtwo/README.md. The rest of this README documents the layout and conventions of the repo for maintainers and anyone adding another plugin to the marketplace.

What's in here

plugins/
├── .claude-plugin/
│   └── marketplace.json     # marketplace manifest — lists every plugin in this repo
├── dtwo/                     # the dtwo plugin
│   ├── .claude-plugin/
│   │   └── plugin.json       # plugin manifest (name, version, metadata)
│   ├── .mcp.json             # MCP servers this plugin contributes (dtwo, HTTP + OAuth)
│   ├── skills/               # auto-discovered skills (each in its own dir with SKILL.md)
│   │   ├── setup/SKILL.md
│   │   ├── dtwo-gateway-config/SKILL.md
│   │   ├── dtwo-gateway-policy/SKILL.md
│   │   └── dtwo-policy-rego/SKILL.md
│   └── README.md             # end-user plugin docs
└── README.md                 # this file

How a Claude Code plugin marketplace is structured

A marketplace is a git repo whose root contains .claude-plugin/marketplace.json. The manifest lists one or more plugins, each pointing at a subdirectory of the same repo (or a remote source). Customers add the marketplace once with:

/plugin marketplace add <owner>/<repo>

…then install individual plugins from it with:

/plugin install <plugin>@<marketplace>

Each plugin in turn is a directory laid out like this:

Path	Required	What it does
.claude-plugin/plugin.json	yes	Plugin manifest (name, version, metadata).
.mcp.json	optional	MCP servers the plugin registers when enabled.
skills/<name>/SKILL.md	optional	Auto-discovered skills. One directory per skill, file must be SKILL.md.
commands/*.md	optional	Auto-discovered slash commands.
agents/*.md	optional	Auto-discovered subagents.
hooks/hooks.json	optional	Event hooks (PreToolUse, Stop, etc.).

Auto-discovery scans these default paths automatically. Custom paths can be set in plugin.json but aren't needed for the standard layout.

The dtwo plugin uses only skills/ and .mcp.json — the other optional paths (commands/, agents/, hooks/) are omitted.

Adding another plugin to this marketplace

1. Create a new directory at the repo root, e.g. dtwo-foo/.

2. Add dtwo-foo/.claude-plugin/plugin.json with at minimum a name field.

3. Add the plugin's components (skills, .mcp.json, etc.) under that directory.

4. Add an entry to .claude-plugin/marketplace.json:

   {
     "name": "dtwo-foo",
     "source": "./dtwo-foo",
     "description": "..."
   }

   The source string must start with ./ and point at a subdirectory — bare "." is rejected by the schema. Leave version out of the marketplace entry; it belongs in the plugin's own plugin.json (see Releases).

Customers will then install it alongside the existing plugin with /plugin install dtwo-foo@dtwo.

Maintaining the schema digest (dtwo-gateway-config)

The dtwo-gateway-config skill's SKILL.md carries a ### Schema Digest subsection between sentinel markers (<!-- BEGIN SCHEMA DIGEST --> / <!-- END SCHEMA DIGEST -->) that is generated from schema-reference.json — do not edit it by hand.

Why inline: production Claude Code does not auto-load a skill's references/ directory; only SKILL.md is in the cached system prompt. To get field-level schema grounding to real users, the digest must live inline in SKILL.md.

To regenerate after a schema bump (or to confirm the digest is in sync):

# Refresh the vendored schema from the d2 source of truth, then regenerate
cp <path>/d2/packages/libs/utils/schema-reference.json dtwo/skills/dtwo-gateway-config/schema-reference.json
node scripts/generate-schema-digest.mjs
git diff dtwo/skills/dtwo-gateway-config/SKILL.md

# CI / pre-commit guardrail — exits 1 if SKILL.md is stale relative to the vendored schema
node scripts/generate-schema-digest.mjs --check

Custom paths work too: node scripts/generate-schema-digest.mjs --schema=PATH --skill=PATH.

The generator is dependency-free (Node ESM, single file, ~280 LOC) so it runs anywhere Node 17+ is available.

Releases

Installs are version-gated: /plugin update and fresh installs only pick up changes when the version number changes. So any change to distributed plugin content (a SKILL.md, .mcp.json, etc.) must bump the version in the plugin manifest (<plugin>/.claude-plugin/plugin.json). The version lives only there — don't add one to the marketplace entry, since Claude Code always prefers the plugin.json value and a stale marketplace copy would silently mask it. Changes to non-distributed paths only (skill-harness/, scripts/, docs, CI) don't need a bump. Tag the release commit (e.g. dtwo-v0.2.0) so customers can pin to a specific version when needed. See CLAUDE.md for the agent-facing version of this rule.

Local development

To test changes without pushing:

/plugin marketplace add /absolute/path/to/plugins
/plugin install dtwo@dtwo
/reload-plugins

After edits, run /plugin update dtwo@dtwo followed by /reload-plugins to pick up changes.

When you're done, /plugin uninstall dtwo@dtwo and /plugin marketplace remove dtwo cleans up so the published GitHub install is unambiguous.

License

MIT. The plugin scaffold and skill prose are open source.