spec-driven-development

spec-driven-development is a skill for Claude Code, Codex from pimenov/codex-first-skills-pack. It costs 101 tokens per session (1,906 once invoked), scanned A, original, no licence file.

A development method that defines the work contract before planning or coding, including goals, users, scope, assumptions, acceptance criteria, and verification. Acceptance criteria are the conditions that must be met for the work to count as complete.

In plain words
What is it for?
Use it when creating or changing features, workflows, APIs, integrations, migrations, user-facing behavior, or team handoffs.
Why use it?
It reduces unclear requirements and gives implementation and review a shared definition of done.

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/pimenov/codex-first-skills-pack/spec-driven-development
Any agent
npx skills add pimenov/codex-first-skills-pack --skill spec-driven-development
Clone the repo
git clone --depth 1 https://github.com/pimenov/codex-first-skills-pack

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for spec-driven-development

README.md
[![agentmods](https://agentmods.dev/badge/skills/pimenov/codex-first-skills-pack/spec-driven-development.svg)](https://agentmods.dev/skills/pimenov/codex-first-skills-pack/spec-driven-development)
Your own site
<a href="https://agentmods.dev/skills/pimenov/codex-first-skills-pack/spec-driven-development"><img src="https://agentmods.dev/badge/skills/pimenov/codex-first-skills-pack/spec-driven-development.svg" alt="Measured on agentmods" height="20"></a>
Per session 101 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,906 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00101 $0.01906
Opus 5 $0.00051 $0.00953
Sonnet 5 $0.00020 $0.00381
Haiku 4.5 $0.00010 $0.00191

Measured 5d ago against content hash 7e9e89b3b577, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

spec-driven-development 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.

skills/spec-driven-development/SKILL.md · 270 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 5d ago First seen · 270 lines · 101 tokens per session scan A 7e9e89b3b577

Subscribe to this mod's changes

spec-driven-development is a skill published in the GitHub repository pimenov/codex-first-skills-pack (23 stars, last pushed 2mo ago), with no licence file. It adds 101 tokens to every session and 1,906 once invoked, about $0.0005 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.

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