Spec Kitty is an open-source command-line tool that turns product requirements into a repository-based workflow for AI-assisted software development. It stores specifications, plans, tasks, acceptance criteria, reviews, and merge decisions in Git while giving agents isolated git worktrees for parallel implementation. The catalogue add-ons support the project's workflows for coordinating agents and governing their work.
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 skills add Priivacy-ai/spec-kitty --skill spec-kitty-spdd-reasonsgit clone --depth 1 https://github.com/Priivacy-ai/spec-kittyWrote 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/priivacy-ai/spec-kitty/spec-kitty-spdd-reasons)<a href="https://agentmods.dev/skills/priivacy-ai/spec-kitty/spec-kitty-spdd-reasons"><img src="https://agentmods.dev/badge/skills/priivacy-ai/spec-kitty/spec-kitty-spdd-reasons/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/priivacy-ai/spec-kitty/spec-kitty-spdd-reasons"><img src="https://agentmods.dev/badge/skills/priivacy-ai/spec-kitty/spec-kitty-spdd-reasons.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 5.1 | $0.00118 | $0.01882 |
| Opus 5.5 | $0.00047 | $0.00753 |
| Sonnet 5.5 | $0.00024 | $0.00376 |
| Haiku 4.5 | $0.00012 | $0.00188 |
Grade A, and why
spec-kitty-spdd-reasons 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 1mo 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 — 178 lines — stays where its author put it; the contents beside it link to each section on GitHub.
spec-kitty-spdd-reasons
Drive REASONS Canvas authoring and review for missions that opted in to Structured-Prompt-Driven Development (SPDD) via charter selection. The canvas is a thin, agent-curated reasoning layer that sits next to the spec, plan, and tasks; it is not a duplicate system mirror.
This skill is documentation for the agent. It assumes the SPDD/REASONS
doctrine pack (paradigm, tactics, styleguide, directive, template) has
already been shipped under src/charter/offering/ and that activation can be
detected via the helper described below.
What this skill does
- Detects whether the SPDD/REASONS pack is active for the current project.
- Loads mission context:
spec.md,plan.md,tasks.md, per-WP prompts, charter context, glossary, research notes, contracts, and relevant code. - Generates or updates
kitty-specs/<mission>/reasons-canvas.mdfrom the seven-section template fragment. - Compiles per-WP REASONS summaries when an implementer or reviewer asks for one (a focused slice of the canvas scoped to a single work package).
- Runs comparison-mode review: traces a diff against the canvas and classifies divergences using the drift taxonomy.
What this skill does NOT do
- It does NOT mirror the code as prose. The canvas references source artifacts; it does not duplicate them. Code remains the source of truth for current behavior.
- It does NOT overwrite user-authored mission artifacts. When a canvas section already contains user content, the skill merges by appending or refining, never by silent rewrite.
- It does NOT silently enforce SPDD on projects that did not opt in via charter. If the user demands enforcement and the charter is not configured, escalate to the charter workflow.
Activation rules
Three branches:
- Active — charter selected the SPDD/REASONS pack (paradigm
structured-prompt-driven-development, tacticreasons-canvas-fill, tacticreasons-canvas-review, or directiveDIRECTIVE_038). Proceed with canvas authoring or review using the seven-section template atsrc/charter/offering/templates/fragments/reasons-canvas-template.md. - Inactive + ad-hoc request — user asked to "use REASONS" once, without charter opt-in. Proceed, but stamp the canvas header with a "not formally opted in via charter" note so reviewers know the canvas is advisory only.
- Inactive + enforcement demand — user wants REASONS enforced as a gate but the charter has not selected the pack. Do NOT enforce. Escalate to the charter workflow: suggest running the charter interview to add the paradigm or directive, then return to this skill.
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.
- 1mo ago Changed 3e5d2a69f2d8
- 1mo ago First seen · 178 lines · 118 tokens per session scan A 01586b231933
spec-kitty-spdd-reasons is a skill published in the GitHub repository Priivacy-ai/spec-kitty (1,687 stars, last pushed 9d ago), licensed MIT. It adds 118 tokens to every session and 1,882 once invoked, about $0.0005 per session on Opus 5.5. 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.
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spring-boot-4-conventions
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clarity-over-cleverness
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junit5-testcontainers-patterns
JUnit 5 + Spring Boot 4 test slice patterns and Testcontainers integration test patterns with @ServiceConnection. Use when writing or reviewing any test, especially when choosing between unit / slice / integration scope.
ears-spec-authoring
Author acceptance criteria using EARS-lite shapes with stable AC-NNN IDs and explicit Q-NNN open questions. Use when drafting or editing 01-spec.md, when transforming a tracker ticket into ACs, or when a user asks for a spec / requirements doc.