Grips Intelligence MCP server (v2)

A Model Context Protocol (MCP) server that exposes the Grips Intelligence e-commerce data API to any MCP client — Claude Desktop, Cowork, Claude Code, etc.

v2 is a clean rebuild of v1 with defensive data handling baked in from day one. It fixes the ".map is not a function" class of bugs that v1.x needed a runtime patch to address — thin or unknown domains now degrade to a clean "no data" response instead of crashing the tool call.

What's in it

All tools default to markdown output for readability. Pass format: "json" for machine-parseable output.

Installation

npm install

The prepare script auto-builds dist/ when you run npm install.

Configuration

Set your Grips API key in the MCP client's server config. For Claude Desktop, that's ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "grips": {
      "command": "node",
      "args": [
        "/ABSOLUTE/PATH/TO/grips-mcp-server-v2/dist/index.js"
      ],
      "env": {
        "GRIPS_API_KEY": "your-api-key-here",
        "GRIPS_DEFAULT_COUNTRY": "US"
      }
    }
  }
}

Required env:

• GRIPS_API_KEY — your Grips API token (sent as the grips-api-key header).

Optional env:

• GRIPS_DEFAULT_COUNTRY — US, GB, or DE. Defaults to US if unset or invalid.

After editing the config, fully quit Claude Desktop (Cmd+Q — not just closing the window) and reopen.

What's different from v1

v1 crashed on a specific API response shape: when Grips returned a thinly-covered or unknown domain, the timeseries field came back as {} rather than null, undefined, or []. The code used (data.timeseries ?? []).map(...), which only guards against null/undefined — not against {}. Result: "data.timeseries ?? []).map is not a function".

v2 routes every payload field through toArray<T>() (for arrays) or toObject<T>() (for dict-shaped responses like the devices endpoint) before use. Any non-array / non-object value falls through to a safe empty default, and the tool returns a clean "no data" response instead of throwing.

Other changes:

• Date normalisation is consistent (every date becomes YYYY-MM-DD in UTC) across all tools, so rows don't slip across day boundaries in non-UTC timezones.

• Currency / integer / percent formatters render — for missing values instead of $NaN or 0.00%.

• Error messages now include actionable hints — 401 → "check your API key", 429 → "rate-limited, narrow your window", etc.

• Per-domain error isolation in grips_compare_domains — one thin domain in an 8-domain compare no longer breaks the other seven.

• Character-budget truncation — responses cap at ~200KB with a visible notice so multi-domain pulls don't blow up the context window.

Development

npm run dev    # watch mode, rebuilds on change
npm run build  # one-shot build to dist/

Testing from the command line

Test that the server boots without errors (it will exit on EOF from stdin):

GRIPS_API_KEY=your-key node dist/index.js < /dev/null

You should see [grips-mcp] grips-mcp-server v2.0.0 ready (default country: US). on stderr and no crash.

For interactive testing, use @modelcontextprotocol/inspector:

npx @modelcontextprotocol/inspector node dist/index.js

API reference

Grips documents their public schema at https://gripsintelligence.com/knowledge-base/api. The queries this server uses are copied verbatim from that page.

Supported countries today: US, GB, DE. Everything else will error at the API.

Licence

Private — not for external distribution.