MCP server for the DecimalAI skills registry — the registry that ranks agent skills by measured effectiveness (verified A/B benchmarks, live pass rates, AI rater scores), not download counts.

Gives any MCP client (Claude Desktop, Claude Code, Cursor, …) three read-only tools:

Tool	What it does
`search_skills(query, category?, sort?, limit?)`	Hybrid keyword/semantic search over the public registry
`get_skill(slug)`	Full record: trust & safety-scan status, verified benchmark lift, SkillScore, ratings, SKILL.md body
`get_leaderboard(sort?, category?, window_days?, limit?)`	Ranked leaderboard: `skill_score`, `biggest_improvement`, `efficiency`, `top_rated`

No API key required — all three tools read public registry endpoints. If you set DECIMAL_API_KEY (from app.decimal.ai/settings), the same tools additionally show which skills your org has already installed (installed_as).

Install

pip install decimalai-mcp
# or, no install needed at config time:
uvx decimalai-mcp

Requires Python 3.10+.

Claude Code

claude mcp add decimalai -- uvx decimalai-mcp
# with an API key:
claude mcp add decimalai -e DECIMAL_API_KEY=dai_sk_... -- uvx decimalai-mcp

Claude Desktop

Add to claude_desktop_config.json (Settings → Developer → Edit Config):

{
  "mcpServers": {
    "decimalai": {
      "command": "uvx",
      "args": ["decimalai-mcp"],
      "env": {
        "DECIMAL_API_KEY": "dai_sk_optional"
      }
    }
  }
}

Omit the env block entirely for anonymous read-only access.

Configuration

Env var	Default	Purpose
`DECIMAL_API_KEY`	(unset)	Optional. Unlocks per-org enrichment (e.g. `installed_as`) on the same public endpoints.
`DECIMAL_API_URL`	`https://api.decimal.ai`	Point at a self-hosted / local backend.

Why no `check_manifest_impact` tool?

The manifest-impact endpoint (POST /api/v1/regression-check) is authenticated on the platform — it analyzes your org's production traces against a candidate manifest, so there is no public variant to expose. This server is deliberately a read-only, key-optional public-registry surface. If demand shows up, an authed check_manifest_impact (requiring DECIMAL_API_KEY) is a natural v0.2 addition; the regression-check GitHub Action covers the CI use-case today.

Endpoints used (all public)

GET /api/v1/registry/skills — browse/search
GET /api/v1/registry/skills/{slug} — detail
GET /api/v1/registry/leaderboard — ranked leaderboard (category filtering falls back to the browse endpoint's documented view=ranks mode, because the leaderboard endpoint is uncategorized)

Development

pip install -e ".[dev]"
pytest              # all HTTP mocked; no network
python -m decimalai_mcp.server   # run over stdio

Run pytest yourself before opening a PR. CI also asserts that the pinned mcp<2 still provides FastMCP, which the mocked tests do not cover — run that one too:

python -c "from mcp.server.fastmcp import FastMCP; import decimalai_mcp.server"

Releases are cut from a published GitHub Release — see RELEASING.md for the gates a change has to pass and the version strings that must move together.