cavekit is a Claude Code plugin that organizes software changes through a compact, spec-driven workflow stored in a SPEC.md file. It is for developers who want to plan, research, review, and build changes while preserving project context across sessions; the catalogue entries are its skills, commands, plugin configuration, and workflow rules.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/juliusbrussee/cavekit/cavemannpx skills add JuliusBrussee/cavekit --skill cavemangit clone --depth 1 https://github.com/JuliusBrussee/cavekitWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/juliusbrussee/cavekit/caveman)<a href="https://agentmods.dev/skills/juliusbrussee/cavekit/caveman"><img src="https://agentmods.dev/badge/skills/juliusbrussee/cavekit/caveman.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00065 | $0.00819 |
| Opus 5 | $0.00032 | $0.00409 |
| Sonnet 5 | $0.00013 | $0.00164 |
| Haiku 4.5 | $0.00006 | $0.00082 |
Grade A, and why
caveman scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.
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.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 5d ago First seen · 119 lines · 65 tokens per session scan A 9a93187ecba5
caveman is a skill published in the GitHub repository JuliusBrussee/cavekit (1,142 stars, last pushed 21d ago), licensed MIT. It adds 65 tokens to every session and 819 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
build-executor
Govern implementation from an approved execution contract. Invoke when execution-contract.md is approved and the user wants disciplined build work, TDD execution, or guarded batch-by-batch implementation.
workflow-start
Primary entry point for the spec-superflow state-machine workflow. Invoke when the user is inside an active spec-superflow change directory (look for .spec-superflow.yaml, changes/ /, proposal.md, specs/, design.md, tasks.md, or execution-contract.md) and asks to start, continue, resume, implement, plan, or figure out…
release-archivist
Close out a spec-superflow change with verification, summary, and archive readiness. Invoke when implementation is complete, verification is underway, or the user asks for a final wrap-up.
bug-investigator
Use when encountering any bug, test failure, or unexpected behavior during spec-superflow execution, before proposing fixes. Invoked automatically when build-executor hits a blockage.
contract-builder
Convert approved planning artifacts into an execution contract. Invoke when the user wants to start building, asks to move from planning to implementation, or when execution-contract.md is missing or stale.
spec-writer
Create or refine spec-superflow planning artifacts. Invoke when the change is understood well enough to write proposal.md, specs/, design.md, and tasks.md.