Skip to content

/caveman

Caveman encoding for SPEC.md and spec-adjacent writes. Loaded by /spec, /build, /check. Cuts tokens ~75% vs prose while staying precise. Triggers on any write to SPEC.md or when user says "caveman", "compress this", "be brief".

From plugin
ck
1.2k9 skills7 commands

Claude Code

$ npx -y skills add JuliusBrussee/cavekit --skill caveman --agent claude-code

SKILL.md

caveman.SKILL.md
name: caveman
description: |
  Caveman encoding for SPEC.md and spec-adjacent writes. Loaded by /spec, /build,
  /check. Cuts tokens ~75% vs prose while staying precise. Triggers on any write
  to SPEC.md or when user says "caveman", "compress this", "be brief".

caveman — spec encoding

Applies to SPEC.md writes, spec-referencing prose, backprop entries. Does NOT apply to code, error strings, commit messages, PR descriptions.

GRAMMAR

  • Drop articles (a, an, the).
  • Drop filler (just, really, basically, simply, actually).
  • Drop aux verbs where fragment works (is, are, was, were, being).
  • Drop pleasantries.
  • No hedging (skip "might", "perhaps", "could be worth").
  • Fragments fine.
  • Short synonyms: fix > implement, big > extensive, run > execute.

SYMBOLS

Prefer over words:

→   leads to / becomes / on <x>
∴   therefore / fix
∀   for all / every
∃   exists / some
!   must / required
?   may / optional / unknown
⊥   never / forbidden / nil
≠   not equal
∈   in
∉   not in
≤   at most
≥   at least
&   and
|   or
§   section reference

PRESERVE VERBATIM

Never compress:

  • Code blocks, snippets, one-liners with backticks.
  • Paths: `src/auth/mw.go`.
  • URLs.
  • Identifiers: function names, variable names, env vars.
  • Numbers and versions.
  • Error message strings.
  • SQL, regex, JSON, YAML.
  • Quoted strings.

SHAPES

**Invariant**:

V<n>: <subject> <relation> <condition>
V1: ∀ req → auth check before handler
V2: token expiry ≤ current_time → reject

**Bug row** (pipe table under §B):

id|date|cause|fix
B1|2026-04-20|token `<` not `≤`|V2

**Task row** (pipe table under §T):

id|status|task|cites
T3|x|add auth mw|V1,I.api

Status: `x` done, `~` wip, `.` todo. Escape literal `|` as `\|`.

**Interface**:

<kind>: <name> → <shape>
api: POST /x → 200 {id:string}
cmd: `foo bar <arg>` → stdout JSON
env: FOO_KEY ! set

EXAMPLES

**Bad**: > The system should ensure that every incoming request is properly authenticated before being forwarded to its corresponding handler function.

**Good**: > V1: ∀ req → auth check before handler

**Bad**: > We discovered that the token expiration check in the middleware was using a strict less-than comparison operator, which meant tokens were being rejected at the exact moment of their expiry.

**Good**: > B1: token `<` not `≤` → reject @ expiry boundary.

**Bad**: > The POST endpoint at /x accepts a JSON body and returns a 200 response with an object containing the created id.

**Good**: > api: POST /x → 200 {id}

BOUNDARIES

  • User asks for prose explanation → switch to normal English.
  • Spec documents for external review (RFC, pitch) → normal English.
  • Commit message → normal English (git readers expect it).
  • Diff comment in code → normal English.

WHEN UNSURE

If cutting a word loses a fact, keep it. Caveman is compression, not amputation.

Read more
@juliusbrussee
Ships withck

Frozen — compressed spec-driven development plugin for Claude Code. Still works; active development moved to JuliusBrussee/caveman.

Stars on GitHub

Momentum

stars in total
1.2k
Star history of JuliusBrussee/cavekit on GitHub, a chart by star-history.com

Other skills on ck.

backprop
Auto-invoked

backprop

Bug → spec protocol. When a bug is found or a test fails, trace the cause, decide whether a new §V invariant would catch…

@juliusbrussee@juliusbrusseeInstall Skill
build
Auto-invoked

build

Plan-then-execute implementation against SPEC.md. Native single-thread loop, no sub-agents. On test or build failure,…

@juliusbrussee@juliusbrusseeInstall Skill
check
Auto-invoked

check

Read-only drift detector. Diffs SPEC.md against current code and reports violations grouped by severity. Writes nothing —…

@juliusbrussee@juliusbrusseeInstall Skill
deepen
Auto-invoked

deepen

Optional design-improvement pass for when you have spare usage to drain. Finds the shallowest modules in the code the spec…

@juliusbrussee@juliusbrusseeInstall Skill
grill
Auto-invoked

grill

Calibrated interrogation of a fuzzy idea before it becomes a spec. Asks one question at a time, recommends an answer, and lands…

@juliusbrussee@juliusbrusseeInstall Skill
research
Auto-invoked

research

Gather external knowledge the spec needs and distill it into §R — the durable research log — so build grounds in facts instead of…

@juliusbrussee@juliusbrusseeInstall Skill

More skills from other plugins.

improve

improve

Survey any codebase as a senior advisor and produce prioritized, self-contained implementation plans for OTHER models/agents to…

improve8w9.3k
@shadcn@shadcnInstall Skill
kiro-debug

kiro-debug

Investigate implementation failures using root-cause-first debugging. Use when an implementer is blocked, verification fails, or…

cc-sdd2w3.7k
@gotalab@gotalabInstall Skill
deep-discuss

deep-discuss

结构化深度讨论 Skill,用于与用户进行多轮问题分析和方案设计。当用户描述一个问题现象、故障表现、 技术困惑、方案选择困难,或明确说"讨论一下"、"帮我分析"、"我遇到一个问题"、"你觉得怎么样"、 "帮我想想"、"我在纠结"时,必须使用本…

Questions about caveman.

Which coding agents can use caveman?
caveman installs in Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot, OpenCode and Windsurf with the skills CLI, using each agent's flag shown on this page. Flowy's auto-invocation, which fires a skill when your prompt matches, runs in Claude Code only.