Customize with Claude & Aspen Builder

Last updated: September 21, 2026

Step 1: Download Aspen Builder

  • Aspen Builder is an electron app that enables you to make declarative customizations and extensions of the Aspen data model

  • Contact your account representative to get the link to download Aspen Builder

Step 2: Open Aspen Builder and log into your instance

  • Open Aspen Builder

  • Copy and paste your Instance URL into the Instance URL field

  • Click Sign in

  • Aspen Builder will create the local folders on your computer and install the Aspen CLI

~/Aspen/<domain>_<instance>/
  .aspen/bin/aspen        # the CLI — not on PATH, run it by this path
  metacode/               # platform + your authored metadata

Step 3: Install the local stdio MCP for Claude Code

The Aspen Claude plugins will be available soon. Until then, you can install the local stdio MCP for Claude Code.

> curl -fsSL https://raw.githubusercontent.com/aspen-crm/aspen-tools/main/plugins/aspen/cowork/bin/install-runtime-mcp.sh | sh -s --instance https://0000-00-5101.ip.aspen-crm.com/emcap.com/emcap/

Step 4: Sign in the CLI from the terminal

Aspen Builder typically signs the CLI in for you as part of Step 2. If a command ever answers back "No instance is logged in", or you're setting up the CLI side on its own, then sign in directly, from inside the instance folder:

> cd ~/Aspen/emcap.com_emcap
> .aspen/bin/aspen login --instance https://0000-00-5101.ip.aspen-crm.com/emcap.com/emcap/

A browser tab will open for you to log into your Aspen instance, after which you're ready to start customizing Aspen with Claude Code.

Step 5: Start Claude Code inside the instance folder

Pre-requisites

  • Aspen MCP (see above)

  • node.js (download if you don't already have it installed)

  • Claude Code

From the instance folder:

cd ~/Aspen/emcap.com_emcap
claude

In the Claude Code session, add the plugins and if it asks for scope, select User:

/plugin marketplace add aspen-crm/aspen-tools

Then

/plugin install aspen-code@aspen

A new skill called using-aspen is now available to you. Verify it's working by asking Claude to describe your Aspen instance to you.

Tips

For a simple test run, try asking Claude Code to create a custom object called "Events" in your instance and describe what type of events you'd like to have with your customers.

For an advanced use case, try asking Claude to create a new Tab Collection, with a tab called Support. Prompt Claude to create a Kanban board for managing your cases.