spec-lint

A pre-save checker for software specification drafts. It tests diagram syntax, required diagrams, links between acceptance criteria and sequences, design decisions, and system-change rows.

In plain words
What is it for?
Use it while writing a specification to check PlantUML diagrams, required diagram types, acceptance-criteria coverage, design quality, and system-delta entries.
Why use it?
It catches specification problems before save-time checks reject the file. The report shows which checks pass or fail without changing the draft.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/friedbotstudio/baseline/spec-lint
Any agent
npx skills add friedbotstudio/baseline --skill spec-lint
Clone the repo
git clone --depth 1 https://github.com/friedbotstudio/baseline

Made for: Claude Code, Codex.

Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 929 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00071 $0.00929
Opus 5 $0.00036 $0.00464
Sonnet 5 $0.00014 $0.00186
Haiku 4.5 $0.00007 $0.00093

Measured 2d ago against content hash c78fcebc63be, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

spec-lint 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 2d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (lint.mjs), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.claude/skills/spec-lint/SKILL.md · 76 lines

How it starts

The opening of the file, as written. The whole thing — 76 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Checker config (tier-dial:read-path): this checker's floor/ceiling come from the tier dial at .claude/hooks/lib/tier-dial.mjs via resolveCheckerThreshold('spec'). Advisory only this slice (v1 piece 2); blocking is piece 5.

spec-lint — preflight a spec draft

Invocable by both user (/spec-lint <slug>) and Claude (when iterating on a spec and wanting to check status before writing).

What it checks

Five checks always run, same logic as the hooks, but advisory (no writes are blocked). One more appears only when its trigger fires.

Checks are identified by row name, in the order the report prints them. Ordinals are deliberately absent: they have already drifted once — lint.mjs labels the codesign check "#4" in its own comment while the report prints it last — and a number that means one thing in the source and another in the table is worse than no number.

Check Row name Hook it mirrors
Every plantuml fence parses under plantuml -checkonly plantuml_syntax plantuml_syntax_guard
Required diagram kinds present (config: project.json → artifacts.required_diagrams.spec) diagram_presence spec_diagram_presence_guard
Every AC-NNN row in the Acceptance criteria table references a §Behavior #N section that exists ac_traceability (no hook — unique to the lint)
Each ## Design calls row carries a populated Reference target and Quality criteria design_calls spec_design_calls_guard
Each ## System delta row resolves — an add anchors inside the governed surface, a change/remove names an existing element system_delta (no hook — the guard checks only that the section is present)
Conditional check Row name Fires when
A ## Decisions section is present codesign_decisions workflow.json → codesign_mode is true

system_delta reports SKIP when project.json → memory.architecture_map.enabled is not true. The corpus at docs/system/ is opt-in, so a project that has not adopted it declares no delta and the check has nothing to resolve.

Read the full file on GitHub · 76 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

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.

  1. 2d ago First seen · 76 lines · 71 tokens per session scan A c78fcebc63be

Subscribe to this mod's changes

spec-lint is a skill published in the GitHub repository friedbotstudio/baseline (11 stars, last pushed 6d ago), licensed Apache-2.0. It adds 71 tokens to every session and 929 once invoked, about $0.0004 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.