Install and run AAJ skills and engines: every agent, step by step

Start here: pick one of three routes

The fastest way to use an AAJ engine is to add the hosted server to your AI client: no install, no sign-in, about a minute. If you want the skills themselves in your project, install them with one command. If you cannot use a terminal, copy the folders by hand.

AAJ has 73 skills, and 62 of them have an engine: a script that takes your numbers and returns a number and a verdict, the same answer every time. The 11 skills without an engine give the method only.

Every answer built on an AAJ skill should open with an "AAJ ... engine result:" line and show the engine's output. If yours does not, see Troubleshooting.

Route 1: add the hosted MCP server (no install)

The server address is the same for every client:

It needs no sign-in and gives your agent five tools: list_engines, describe_engine, run_engine, search_skills and get_skill. It runs the engines in memory and keeps no copy of what you send.

Claude (web and desktop app)

1. Open Settings, then Connectors.
2. Click Add custom connector.
3. Paste the address above, name it "AAJ Marketing Engines", and save.
4. Start a new chat and ask: "Use the AAJ engines to check my unit economics: CAC $1,200, ARPA $300 a month, 80% gross margin, 3% monthly churn."

Claude Code

1. In a terminal, run: claude mcp add --transport http aaj-engines https://aaj-engines-mcp.sarojkjha10.workers.dev/mcp
2. Start Claude Code and run /mcp to confirm aaj-engines is connected.
3. Ask the same question as above.

ChatGPT, Cursor, Windsurf and other MCP clients

1. Open your client's settings for MCP servers or custom connectors. The name varies by client.
2. Add a remote server of type Streamable HTTP with the address above, and no authentication.
3. Ask the same question and check that the answer shows the engine's output.

AAJ has verified the hosted server from Claude. The steps for the other clients follow each product's usual way of adding a remote server and have not yet been tested by AAJ; if a client asks for a different setting name, use its own documentation for adding a remote MCP server.

If you prefer a local server

The same five tools can run on your machine, so AAJ receives nothing. It needs Node 18 or later and a clone of the repository.

1. Download or clone github.com/sarojkjha/aaj-marketing-skills.
2. Add this to your client's MCP settings, with the real path to the file:

On Windows, write the path with forward slashes or doubled backslashes, for example C:/Users/you/aaj-marketing-skills/platform/mcp/server.mjs.

Route 2: install the skills with one command

This needs Node.js 18 or later. Check with node --version. The command installs the skills into the folder you run it from, so choose that folder first.

Windows (Command Prompt)

1. Press the Windows key, type cmd, and open Command Prompt the normal way. Do not choose "Run as administrator". Windows blocks the installer from writing into protected folders, and an administrator window opens in C:\Windows\System32, where the install fails with EPERM: operation not permitted.
2. Make a project folder and go into it:

1. Install one skill, for example the A/B test engine:

1. When it asks Which agents do you want to install to?, pick only the agent you will use (see the table in the next section). Choose Project scope and Symlink, then answer Yes.
2. Check that the folder aaj-demo\.agents\skills\ab-test-significance now exists.
3. If the installer reports that it cannot create symlinks, run it again and add --copy. Windows only allows symlinks in some setups.

PowerShell works too, if you run it from your own folder and not as administrator. The commands are the same.

Mac and Linux (Terminal)

1. Open Terminal.
2. Make a project folder and go into it:

1. Run the same install command:

1. Pick your agent, choose Project scope and Symlink, and answer Yes.
2. Check with ls .agents/skills.

Useful variations

The agent names for --agent are in the table in the next section.

Claude Code and Codex plugins (an alternative to the command)

The plugin adds all 73 skills and also starts the local MCP server, so Claude can call run_engine directly. It runs on your machine and AAJ receives nothing.

• Claude Code (version 2.1.275 or later): /plugin marketplace add sarojkjha/aaj-marketing-skills, then /plugin install aaj-marketing-skills@aaj. Skills then appear as /aaj-marketing-skills:<skill>.
• Codex: codex plugin marketplace add sarojkjha/aaj-marketing-skills, then codex plugin add aaj-marketing-skills@aaj.

Route 3: copy the folders by hand (no terminal)

This does the same thing as the command, using a download and File Explorer or Finder.

1. Download the repository as a zip file: github.com/sarojkjha/aaj-marketing-skills/archive/refs/heads/main.zip.
2. Unzip it. Inside, open the folder called skills. Each skill is one folder, for example ab-test-significance or unit-economics.
3. In your own user folder, make a project folder called aaj-demo. Inside it, make a folder called .agents, and inside that a folder called skills. On Windows, File Explorer may refuse a name that starts with a dot. Type .agents. with a dot at the end and it will accept it.
4. Copy the skill folders you want from the zip's skills folder into aaj-demo/.agents/skills.
5. Check which folder your agent reads in the table below. If it is not .agents/skills, copy the same folders there as well. Claude Code reads .claude/skills.
6. Keep the copy in .agents/skills even if your agent reads another folder. The skill files point to .agents/skills/<skill>/resources/ when they run an engine.
7. Open aaj-demo as the working folder in your agent, then run your first engine (see below).

The zip always holds the latest version. To update, download it again and replace the folders.

Every agent: where its skills live

The installer supports the agents below. Use the --agent** value** with --agent, and use the folders if you copy by hand (route 3). Project folders are relative to the folder you open in the agent; global folders sit in your home folder (~, which is C:\Users\<you> on Windows).

AAJ has tested the skills in Claude Code and in Codex on Windows (the ab-test-significance skill only). Every other row comes from the installer's own list of agents and has not yet been tested by AAJ. Agents that read .agents/skills are the easiest, because the default install already puts the skills there.

Source: the skills installer's agent list, read on Oct 27, 2026. The list changes as agents are added, so check the installer's own help (npx skills add --help) for the current one.

No agent on the list? The folder is usually in that agent's own documentation under "skills". Copy the skill folders there, and keep the .agents/skills copy as well.

Run your first engine

Open the aaj-demo folder as the working folder in your agent, then ask it a question in plain words and name the engine. This example uses the A/B test engine:

A correct answer has four parts:

1. An opening line that names AAJ: "AAJ ab-test-significance engine result:".
2. The engine's own output block, unchanged:

1. A plain-language reading under it: a 25% lift, but not enough evidence yet, so keep the test running.
2. A Method line pointing to https://skills.aajconsult.com/skills/ab-test-significance.

Two more to try, with their results:

To see all engines, ask your agent to list them, or open the skills catalog.

Run an engine by hand (any computer with Node)

You can also run the script yourself, with no agent. From the aaj-demo folder:

To use your own numbers, pass a JSON object. On Mac and Linux, wrap it in single quotes. On Windows Command Prompt, wrap it in double quotes and escape the inner ones:

Every engine also accepts --help, which prints its inputs, units and a worked example.

Troubleshooting

When the skill and your own agent disagree, the engine's output is the AAJ result. Anything the agent adds under it, such as a confidence interval the engine does not print, is the agent's own estimate and should be labelled that way.

Still stuck? Email saroj@aajconsult.com with the exact text of the error and the agent you used.

This guide is also published at https://skills.aajconsult.com/install.