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-runtime-nextgit 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-runtime-next)<a href="https://agentmods.dev/skills/priivacy-ai/spec-kitty/spec-kitty-runtime-next"><img src="https://agentmods.dev/badge/skills/priivacy-ai/spec-kitty/spec-kitty-runtime-next/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-runtime-next"><img src="https://agentmods.dev/badge/skills/priivacy-ai/spec-kitty/spec-kitty-runtime-next.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Agent Snooping · line 577 Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
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 | $0.00110 | $0.05033 |
| Opus 5.5 | $0.00044 | $0.02013 |
| Sonnet 5.5 | $0.00022 | $0.01007 |
| Haiku 4.5 | $0.00011 | $0.00503 |
Grade A, and why
spec-kitty-runtime-next 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 — 585 lines — stays where its author put it; the contents beside it link to each section on GitHub.
spec-kitty-runtime-next
This skill teaches agents how to advance a Spec Kitty mission through the canonical runtime control loop, including doctrine-aware context loading at each step boundary.
When to Use This Skill
Use this skill when the user wants to:
- Advance a mission to its next step
- Understand what the runtime will do next
- Unblock a stalled mission
- Interpret runtime outcomes (step, blocked, decision_required, terminal)
How the Runtime-Next System Works
The spec-kitty next command is the single entry point for agent-driven mission
execution. Each call returns a deterministic decision about what action the
agent should take next.
Decision Algorithm
The runtime evaluates state in this order:
- Mission state machine — Current phase and available transitions (from
mission-runtime.yamlDAG) - WP iteration check — For
implementandreviewsteps, the CLI bridge manages WP-level iteration WITHOUT advancing the runtime. The runtime only advances when ALL WPs reach terminal/handoff lanes. - Guard conditions — Required artifacts, prerequisites, dependency graph
- Priority ordering — Reviews before implementations, higher-priority WPs first, dependency-free WPs before dependent ones
WP Iteration Logic (Critical)
The CLI bridge (not the runtime) manages WP-level iteration:
- If current step is
implementorreview - AND there are WPs in
plannedorin_progresslanes - THEN return a WP-level decision without advancing the runtime step
- The runtime step only advances when ALL WPs are in terminal/handoff lanes
(
done,approved, orfor_review)
This means multiple calls to spec-kitty next during implementation will
return different WP IDs but the same step_id (e.g., "implement") until all
WPs are done.
Mission Runtime YAML Schema
Missions define steps as a DAG (directed acyclic graph) with dependencies:
mission:
key: software-dev
name: Software Dev Kitty
version: "2.1.0"
steps:
- id: discovery
title: Discovery & Research
depends_on: []
prompt_template: research.md
- id: specify
depends_on: [discovery]
prompt_template: specify.md
- id: plan
depends_on: [specify]
prompt_template: plan.md
- id: tasks
depends_on: [plan]
- id: implement
depends_on: [tasks]
prompt_template: implement.md
- id: review
depends_on: [implement]
prompt_template: review.md
- id: accept
depends_on: [review]
prompt_template: accept.md
What ships with it
2 files 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.
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 7986fd19226c
- 1mo ago First seen · 585 lines · 110 tokens per session scan A 5c98c89fdbc3
spec-kitty-runtime-next is a skill published in the GitHub repository Priivacy-ai/spec-kitty (1,687 stars, last pushed 9d ago), licensed MIT. It adds 110 tokens to every session and 5,033 once invoked, about $0.0004 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.
Other skills, from other repositories
evidence-led-authoring
Shared bootstrap-owner contract for evidence-backed brownfield candidates, provenance, and imported baseline coverage.
implementation-standards
Reference material with coding standards (defensive coding, error handling, testing patterns). Loaded on demand by the Developer sub-agent (.github/agents/developer.md); not directly invokable.
spring-boot-4-conventions
Spring Framework 7 / Spring Boot 4 idioms and defaults. Use when writing or reviewing controllers, services, configuration, HTTP clients, async/virtual-thread code, or anything touching Spring's programming model.
clarity-over-cleverness
Apply clarity-over-cleverness rewrites — prefer code a junior engineer can read at a glance over compact-but-clever code. Use during /build's simplify step and during /code-simplify (alias "simplify the code"). Never weakens behavior; suite must remain green.
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.