@karlperron, Karl Perron

command-line tools for people who build with coding agents. linters, scanners, gateways. also: startup contracts, games, music.

News

2026-11-09
Fable 5.2 is out, and we got resets
Claude Fable 5.2 shipped today. Paid plans get one to three free Fable limit resets.
2026-11-09
First light
The new karlperron.com is switched on. What is here, and how it is made.

Lint, scan, test and ship agent skills.

grok-astryx-skill
Unofficial Grok Bot skill and tiny helper for building UI with Meta's Astryx CLI and MCP.
Python
skillport
Install one skill folder into Claude Code, Cursor, Codex and Copilot paths and catch copy drift.
Python · agent-skills · claude · codex · copilot · cursor
skilleval
Deterministic A/B eval harness for agent skills. No API key required.
Python · agent-skills · eval
skillguard
Static, no-LLM security scanner for untrusted agent skills.
Python · agent-skills · linter · security
skilldoctor
Lint Agent Skills (SKILL.md) for spec errors, typo keys, and weak descriptions.
Python · agent-skills · linter

Measure, trim and vet MCP servers before you connect them.

mcpsentry
Lint MCP tool manifests for prompt-injection phrasing, missing hints, and incomplete schemas.
Python · linter · mcp · security
mcplazy
Lazy MCP gateway that exposes catalog search and on-demand schemas instead of dumping every tool.
Python · gateway · mcp
mcptax
Measure the hidden token tax of MCP tool schemas before you connect them.
Python · mcp · tokens

Keep the context window small and the memory local.

deltacursor
Append-only journal that returns only what changed since an opaque cursor.
Python · cursor · journal
retainbook
Local-first session notebook for coding agents: record decisions, recall by keyword, print a next-session brief.
Python · memory · notes
ctxtrim
Budgeted trimmer for logs, HTML, Markdown, and JSON before they hit an agent context window.
Python · context · tokens

Catch stale instructions, leaked secrets and machine-sounding prose.

agentdocs-doctor
Check agent instruction files and skills for stale paths, missing commands, and conflicts.
Python
envbroker
Run commands with secrets injected into the child environment, without ever printing the values.
Python · environment · secrets
slopscan
Detect common AI writing tells and generic AI-looking UI patterns in text or HTML/CSS.
Python · linter · writing

Check prompts and API code before moving to Claude Fable 5.2.

fable-migrate-check
Scan code for Messages API usage that breaks or changes when moving to Claude Fable 5.2.
Python
fablescan
Audit prompts and skills for patterns that fight Claude Fable 5.2 prompting guidance.
Python

Everything else, and anything new since this page was built.

Regolith

Break the drifting rock. Every piece splits three ways, and every shot kicks your ship backward.

A nod to Asteroids. Original code, art and rules.
Hull Down

A wireframe plain, three plates of armour, and tanks that shoot back. Long shots pay more.

A nod to Battlezone. Original code, art and rules.
Rimlight

Hold the rim of the tube. Flip to the far side when the climbers get close.

A nod to Tempest. Original code, art and rules.
Perilune

Set down on the pad, gently and upright. Narrow pads pay more, and your fuel has to last from one site to the next.

A nod to Lunar Lander. Original code, art and rules.
Two-Body Problem

A duel around a pair of stars that orbit each other. Torpedoes bend with the gravity, and so do you.

A nod to Spacewar!. Original code, art and rules.
Line Feed

Eat every dot on the page. Gates open and shut on a timer, and a return key sends the cursors home.

A nod to K.C. Munchkin!. Original code, art and rules.