Sheerpower with Claude Code and Claude.ai

Claude Code is Anthropic's AI coding assistant. You tell it in plain words what you want, and it reads, writes and runs code in your project folder. It works in a terminal, in the Claude desktop app and inside VS Code (see the Claude Code documentation).

Sheerpower has rules of its own, and many habits from Python, C and JavaScript do not compile in it. The Sheerpower plugin teaches Claude the difference, and checks its work with the real compiler.

What the plugin gives Claude

• The language rules -- the shape of a program, routines, text, numbers, arrays and clusters, exceptions and files, and the habits from other languages that do not compile -- each with samples that were compiled and run.
• A catalog to look things up -- every statement and function in this tutorial, with the form to write, a working example with its real output, and the known traps.
• A compile check after every edit -- each time Claude writes or changes a .spsrc or .spinc file, sp4gl /validate runs, and any errors, with the compiler's own Help>> advice, go straight back to Claude, which fixes them before going on.
• Four commands you can type -- /sheerpower:help, /sheerpower:new, /sheerpower:validate and /sheerpower:run (below).

Before you start

• Sheerpower installed on Windows, so that sp4gl.exe is in C:\Sheerpower -- see Installing Sheerpower Step-by-Step.
• Claude Code version 2.1.296 or later, installed and signed in -- see Set up Claude Code. To see your version, type claude --version in a Command Prompt.

Installing the plugin

In Claude Code, type these two commands:

The first adds the Sheerpower plugin catalog; the second shows the plugin, where you choose Install. Then start a new Claude Code session (or type /reload-plugins). The same two steps work from a Command Prompt:

claude plugin list should now show sheerpower@sheerpower as enabled. The plugin is installed for you, in every folder you open with Claude Code.

Using it: just ask

You do not need special commands. Ask for what you want in plain words. When Sheerpower is involved, Claude loads the rules, looks up anything it is not sure of and writes the code -- and the compile check makes sure it builds. Some things to try:

• Write a program that loads customers.csv into a cluster and prints the five largest balances.
• How do I find a customer by name in a cluster without a loop? -- Claude looks it up and shows findrow() with a working example.
• Why does total += amount not compile? -- Sheerpower has no +=; it is total = total + amount.
• This program says Unassigned variable on line 14 -- fix it.
• Review orders.spsrc for Sheerpower traps.

The four commands

• /sheerpower:help <name or task> -- looks it up in the catalog: the form to write, what it does, a working example with the output it really printed, and the known traps. For example:
  /sheerpower:help findrow
  On its own, /sheerpower:help lists the plugin's commands.
• /sheerpower:new <program name> <what it should do> -- writes a new program in house style and compiles it clean before handing it over. For example:
  /sheerpower:new invoice_report read invoices.csv and total by customer, highest first
• /sheerpower:validate <file> -- compiles a program and fixes every error until it builds clean. An include file (.spinc) is compiled through the program that includes it. For example:
  /sheerpower:validate weather_web.spsrc
• /sheerpower:run -- runs a program, in one of three ways:
  • /sheerpower:run guess_number.spsrc -- compiles the program and opens it in its own window, where you use it as usual (the .spsrc may be left off). If it does not compile, nothing opens: Claude shows the errors and asks before changing your program. When it ends, Claude tells you how it ended -- and if it stopped on an error, why.
  • /sheerpower:run on its own -- opens the Sheerpower REPL console, where you can try statements, write short programs, and run programs with run 'guess_number.spsrc'.
  • /sheerpower:run guess_number.spsrc answers.txt -- for testing: runs the program without a window, types each line of answers.txt in as if you had typed it, and reports what it printed, its exit code and any error.

What the compile check looks like

Suppose Claude writes total += 5 on line 3 of add_prices.spsrc. As soon as the file is saved, the check compiles it and hands this back to Claude:

Claude changes the line to total = total + 5, the file is compiled again, and the build is clean -- so the code Claude hands you has already been through the compiler.

Updating and removing

• To get a newer version: claude plugin update sheerpower@sheerpower
• To turn it off for a while: claude plugin disable sheerpower@sheerpower (and claude plugin enable sheerpower@sheerpower to turn it back on)
• To remove it: claude plugin uninstall sheerpower@sheerpower

Tips

• Keep your programs in an ordinary folder. sp4gl will not run a program from a temporary folder (a security guard).

Using the Sheerpower skills on claude.ai

If you talk to Claude in a web browser at claude.ai rather than in Claude Code, you can give it the same Sheerpower knowledge as two skills:

• sheerpower-language -- the language rules, the same as the plugin's.
• sheerpower-help -- the catalog: every statement and function, with the form to write, a working example with its real output, and the known traps.

On claude.ai, Claude cannot run sp4gl.exe, so there is no compile check there and none of the four commands that Claude Code supports. Claude tells you plainly that it has not compiled what it wrote: instead, you compile it with sp4gl prog.spsrc /validate and paste any errors back into Claude.ai for it to fix.

To install them:

1. Download the two skill files:
   sheerpower-language-skill-0.1.5-34521b1a.zip
   sheerpower-help-skill-0.1.5-b345afd0.zip
2. Next, make sure code execution is on in Claude.ai: Bottom left, choose Settings > Capabilities.
3. Go to Customize > Skills > + > Create skill > Upload a skill.
4. Upload each zip separately, just as you downloaded it.
5. Try it: ask How do I find a customer by name in a Sheerpower cluster? It should answer with findrow(), a verified example and its traps.

From then on, Claude uses the skills on its own whenever a mention of Sheerpower comes up -- just ask like you do for any other question:

In sheerpower, how do I count from 1 to 10