FlipJump Claude Skill

flipjump-dev is a Claude skill that teaches Claude Code (and any Claude Agent SDK harness) to write, debug, assemble, and run FlipJump programs correctly the first time.

It lives in its own repo, tomhea/skills, and installs as a Claude Code plugin — so it stays up to date automatically instead of you re-downloading a bundle.

What it does

The skill is small and read-on-demand: it activates whenever you mention FlipJump, .fj files, the standard library, or any of its macros. Once active, Claude:

  • Routes to the docs — fetches macro signatures, syntax, and recipes from this site rather than guessing them, instead of inventing macro names that don’t exist.

  • Knows the gotchas — the memory model’s *dw stride, the two byte encodings, init-macro dependencies, and why addr; IS the flip operation (not a no-op).

  • Picks the right namespace — when to reach for bit.* vs hex.*, and the bit-vs-hex size/speed tradeoff.

  • Verifies before declaring done — runs every program through the fj CLI and confirms it halts cleanly with byte-accurate output, instead of staring at the source and hoping.

It deliberately does not duplicate the macro catalogue or the cookbook — it points Claude at this site for the exact spelling of any macro, which is what this site is for.

Install

The skill ships in the flipjump plugin on the tomhe marketplace. From inside Claude Code:

/plugin marketplace add tomhea/skills
/plugin install flipjump@tomhe

Then make sure the fj toolchain the skill drives is on your PATH:

pip install flipjump

Restart Claude Code if it was already running. The skill activates the next time you mention FlipJump.

Use it

Just talk about FlipJump — the skill activates on its own. Open a .fj file, ask Claude to “write a FlipJump program that …”, or mention an STL macro, and it kicks in. You can also point Claude at it explicitly by asking it to use the flipjump-dev skill.

From there Claude orients to the one-instruction language, fetches what it needs from this site, writes the program, and runs it through fj before telling you it’s done.

Source

The skill is developed at tomhea/skills (MIT licensed). Bug reports and improvements are welcome there.