MCP setup

Prerequisites

1. retailerapi account with an API key (rk_live_...)
2. Node 20 or newer installed

Claude Desktop

Edit the config file:

# macOS
~/Library/Application Support/Claude/claude_desktop_config.json

# Windows
%APPDATA%\Claude\claude_desktop_config.json

Add:

{
  "mcpServers": {
    "retailerapi": {
      "command": "npx",
      "args": ["-y", "@retailerapi/mcp"],
      "env": {
        "RETAILERAPI_KEY": "rk_live_YOUR_KEY"
      }
    }
  }
}

Quit and reopen Claude Desktop. The 6 retailerapi tools appear in the tools palette.

Claude Code

Run:

claude mcp add retailerapi \
  --command npx \
  --args "-y,@retailerapi/mcp" \
  --env RETAILERAPI_KEY=rk_live_YOUR_KEY

Or edit ~/.claude/mcp.json directly with the same JSON shape as Claude Desktop. Restart your Claude Code session.

Cursor

Edit ~/.cursor/mcp.json:

{
  "mcpServers": {
    "retailerapi": {
      "command": "npx",
      "args": ["-y", "@retailerapi/mcp"],
      "env": {
        "RETAILERAPI_KEY": "rk_live_YOUR_KEY"
      }
    }
  }
}

Restart Cursor.

Other MCP clients

Cline, Continue, and most other MCP clients use the same config schema. Just point at npx -y @retailerapi/mcp with the env var set.

Verify

In any MCP client, ask: "Use retailerapi to look up UPC 194629116676. What's the price?" The agent should call lookup_product and return real data within a few seconds.

Troubleshooting

• 401 unauthorized — wrong or revoked API key. Check at app.retailerapi.com/app/keys.
• npx hangs — Node version too old. Run node --version and upgrade to 20+ if needed.
• Tool list empty — malformed JSON in config (often a stray comma). Validate with jq.