ARCNM

ARCNM MCP server

Manufacturing should-cost from CAD and drawings, for your agent. Connect ARCNM to Claude, GitHub Copilot, Cursor or any MCP client, and it can price a part from a STEP file or PDF drawing, explain what drives the cost, read the process plan, compare designs, lot sizes and costing environments, and nest sheet-metal orders. Every figure traces back to the physics that produced it.

This repository documents the server. ARCNM hosts it, so there is nothing to install or run.

What you need

An ARCNM account. The Free plan includes 10 calculations a month, no card required. Reading results costs nothing; starting a calculation uses your quota, and check_quota tells your agent how much is left.

Connect

GitHub Copilot in VS Code

Add the server to .vscode/mcp.json:

{
  "servers": {
    "arcnm": {
      "type": "http",
      "url": "https://api.arcnm.io/mcp-server/mcp"
    }
  }
}

Start it from the MCP view and sign in to ARCNM in the browser when asked. To use an API key instead, send it as a header:

{
  "inputs": [
    { "type": "promptString", "id": "arcnm-key", "description": "ARCNM API key", "password": true }
  ],
  "servers": {
    "arcnm": {
      "type": "http",
      "url": "https://api.arcnm.io/mcp-server/mcp",
      "headers": { "Authorization": "Bearer ${input:arcnm-key}" }
    }
  }
}

Claude and Claude Desktop

ARCNM is in the Claude connector directory. Add it there and sign in with your ARCNM account.

Claude Code

claude mcp add --transport http arcnm https://api.arcnm.io/mcp-server/mcp

Then run /mcp in Claude Code to sign in. With an API key:

claude mcp add --transport http arcnm https://api.arcnm.io/mcp-server/mcp \
  --header "Authorization: Bearer $ARCNM_API_KEY"

Cursor

In ~/.cursor/mcp.json (or .cursor/mcp.json in a project):

{
  "mcpServers": {
    "arcnm": {
      "url": "https://api.arcnm.io/mcp-server/mcp"
    }
  }
}

Cursor opens the ARCNM sign-in. With an API key, add "headers": { "Authorization": "Bearer ${env:ARCNM_API_KEY}" }.

Any other MCP client

Point a Streamable HTTP transport at https://api.arcnm.io/mcp-server/mcp. A client that supports MCP authorization finds the sign-in on its own, from the server's protected-resource metadata. Otherwise, send Authorization: Bearer <your ARCNM API key>.

Sign-in and permissions

OAuth. You sign in with your ARCNM account and choose the organization the client may use. The consent screen lists every permission the client asks for, and you can untick any of them. The client sees only that organization's data.

API key. Create one in ARCNM under Settings → API keys and give it only the scopes your agent needs:

Your agent is only ever shown the tools its credential can use.

Tools

With no extra configuration, the server lists these 15 tools. Each one carries its readOnlyHint and destructiveHint, so your client knows which calls only read and which ones change something, and can ask you first.

Price a part

Follow or stop it

Read the result

Improve and compare

Lookups

None of these 15 deletes anything. More tools — direct uploads, parts, ranked cost drivers, costing environments and what-if adjustments, job nests for sheet metal, the materials and tooling catalog, calibration, folders — are listed when your client sends the X-MCP-Toolsets header with the toolsets it wants, or all; see toolsets.

Prompts

The server also ships 5 prompts that walk an agent through a whole job: cost_a_part, compare_calculations, compare_environments, explain_cost and find_cost_drivers.

Try it

• "Quote this STEP file at lot sizes 1, 10 and 100, and tell me where the cost goes."
• "Which three things drive the cost of this part, and what would change them?"
• "Compare this bracket across our costing environments and tell me where to make it."
• "What lot size gives the lowest total cost?"

Support

Questions and problems: hello@arcnm.io, or open an issue here. Documentation: arcnm.io/docs/mcp. Runnable API examples: arcnm/arcnm-examples.

ARCNM is built by rattle mng GmbH in Überlingen, Germany.