Sigistry Plugin Catalog (formerly Claude Registry)

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

Renamed: prefer com.sigistry/plugin-catalog. This legacy endpoint keeps working.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "Sigistry Plugin Catalog (formerly Claude Registry)": {
      "url": "https://clauderegistry.com/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (9)

• search_plugins read-only

  Search the Sigistry marketplace of Claude Code plugins by keyword and/or category. Returns matches with their install command and verification status (the registry runs an eight-check security audit; prefer "verified" plugins when recommending an install).

  Parameters:

  • query — string — keywords, e.g. "database migration"
  • category — string — e.g. "database", "devops", "git"

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• get_plugin read-only

  Get the full details of a single Sigistry plugin by its id, including install commands, component counts, and its security-audit result (per-check pass/fail from the Verified by Sigistry methodology).

  Parameters:

  • id (required) — string — the plugin id, e.g. "sql-safety-net"

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• list_categories read-only

  List the distinct plugin categories in the Sigistry marketplace with a count of plugins in each, plus the total plugin count.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• search_skills read-only

  Search the Sigistry catalog of verified skills (SKILL.md instruction sets for AI agents) by keyword, optionally filtered to one parent plugin. Every skill passed the skill-safety check: no command shadowing, honestly-scoped triggers, no injection or concealment language, no unsafe scripts. Use get_skill to fetch the full portable source of a match.

  Parameters:

  • query — string — keywords, e.g. "changelog" or "security review"
  • plugin — string — restrict to skills shipped by this plugin id

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• get_skill read-only

  Get one Sigistry skill by name, including the full raw SKILL.md source. The source is portable: it can be applied directly in any SKILL.md-aware agent (Claude Code, Claude Desktop, and others) without installing anything, or installed natively in Claude Code via the parent plugin, which keeps it verified and updated. The returned skill passed the Sigistry skill-safety check at the parent plugin's verification date.

  Parameters:

  • name (required) — string — the skill name, e.g. "assessment-scoring" (find names via search_skills)

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• list_scorecards read-only

  List the public MCP servers Sigistry has independently graded against its scorecard rubric (transport, stateless core, lifecycle, authorization, tool design, security hygiene), each with an overall grade A-F and the exact commit graded. Useful before connecting an agent to a third-party MCP server: check whether it has been assessed and how it scored. Use get_scorecard for the full per-axis breakdown.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• get_scorecard read-only

  Get the full scorecard for one graded MCP server by its id: the overall grade, per-axis pass/partial/fail with cited evidence, hardening notes, the rubric version, and the exact commit graded. Grades describe the pinned commit only; a re-grade at a newer commit can be requested via an issue on the marketplace repo.

  Parameters:

  • id (required) — string — scorecard id, e.g. "sigistry-catalog" (find ids via list_scorecards)

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• verify_plugin read-only

  Get the recipe to run the Sigistry verification methodology (the eight static checks that gate the Verified badge: manifest integrity, hook safety, agent tool scopes, command hygiene, skill structure, skill safety, no secrets, documentation) against a plugin BEFORE publishing it. The verification runs entirely on the local machine via a dependency-free open-source Node script; the plugin code never leaves the user's computer and this server performs no computation. Call this when the user wants their plugin or skill checked, then follow the returned steps: download the script, run it against the plugin directory, and fix any FAIL findings it reports.

  Parameters:

  • pluginPath — string — local path to the plugin directory, used to fill in the run command (optional)

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• check_mcp_app read-only

  Get the Sigistry MCP App safety criteria to audit an MCP App (MCP Apps / SEP-1865: a tool that returns an interactive ui:// HTML resource the host renders in a sandboxed iframe) BEFORE shipping it. Returns two groups of checks: spec conformance (ui:// scheme, the text/html;profile=mcp-app mimeType, tool-to-UI linkage via _meta.ui.resourceUri, a text fallback, visibility values, and CSP coverage of external origins) and security hygiene the iframe sandbox does not cover (unsafe DOM sinks, embedded secrets, host-message origin handling, remote scripts). Call this when the user is building or reviewing an MCP App; then apply each check to the app source you have in context and report findings. Nothing is sent to this server; an interactive browser version is at https://sigistry.com/mcp-app-checker.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

Measured by MCPYP probing. Untested fields are omitted, never estimated. Listing is always free; MCPYP never proxies calls or stores user tokens.