Summary

Several plugins distributed through the official claude-plugins-official marketplace do not declare a version in their .claude-plugin/plugin.json (and have no version pinned in the marketplace entry either). As a result, claude plugin list shows them with Version: unknown, and they install into a cache directory named unknown/ rather than a versioned slot.

This is a metadata hygiene issue, not a runtime bug — the plugins load and function correctly. But for an official Anthropic-maintained marketplace it surfaces inconsistency in user-facing output and prevents straightforward version tracking, changelog correlation, and rollback.

Observed State (claude-plugins-official, as of 2026-05-08)

Audited `~/.claude/plugins/cache/claude-plugins-official/<name>/<version>/.claude-plugin/plugin.json`:

Summary: 8 of 14 plugins display as `Version: unknown`. 7 of those have a `plugin.json` but no `version` key. 1 (`session-report`) has no `plugin.json` at all.

Reproduction

```bash claude plugin list

observe several @claude-plugins-official entries with Version: unknown

ls ~/.claude/plugins/cache/claude-plugins-official/code-review/

→ "unknown"

jq '.version' ~/.claude/plugins/cache/claude-plugins-official/code-review/unknown/.claude-plugin/plugin.json

→ null

```

Expected Behavior

Plugins distributed through Anthropic's own official marketplace should populate either:

• `version` in their `plugin.json`, or
• `version` in the marketplace entry (as `swift-lsp` already does)

…so users see a meaningful version string and can correlate against release notes / changelog.

Why an issue rather than a PR

The affected plugins live in `anthropics/claude-plugins-official/plugins/`, so adding `"version": "..."` to each `plugin.json` is mechanically a one-line change. However, the value of that version is a maintainer policy decision (initial version number, semver scheme, future bump conventions) that an external contributor can't make unilaterally. The repository also has no existing tags or releases to derive versions from. Hence this issue rather than a drive-by PR.

Suggested Fix

Add a `version` field to each plugin's `.claude-plugin/plugin.json` (or to the corresponding entry in the marketplace `marketplace.json`). For the plugin with no `plugin.json` at all (`session-report`), create one.

Impact

Low-Medium — Affects user clarity, version tracking, and changelog correlation. Does not break plugin functionality. Notable because it affects the official Anthropic-maintained marketplace specifically.

Environment

• Claude Code CLI 2.1.132
• macOS (Darwin 25.4.0)
• Marketplace: `claude-plugins-official` (anthropics/claude-plugins-official)