spec-miner

spec-miner is a skill for Claude Code from Jeffallan/claude-skills. It costs 100 tokens per session (988 once invoked), scanned A, original, MIT.

A coding guide for reverse-engineering existing software when its requirements or documentation are missing. It maps the code structure, follows data flows, and describes observed behavior and dependencies.

In plain words
What is it for?
Use it to document a legacy codebase, identify entry points and public interfaces, trace request paths, extract requirements from implementation, and find undocumented business rules.
Why use it?
It helps developers understand inherited or undocumented systems before changing them, while marking areas that still need clarification.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the fullstack-dev-skills plugin — 57 skills shipped together

Good fit Use it to document a legacy codebase, identify entry points and public interfaces, trace request paths, extract requirements from implementation, and find undocumented business rules.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jeffallan/claude-skills/spec-miner
About the project

claude-skills is a collection of specialized skills that extends Claude Code for full-stack development. Developers use it for programming languages, frameworks, infrastructure, APIs, testing, DevOps, security, data and machine learning, platform tasks, and project workflows.

Jeffallan/claude-skills · 11,426 stars · on GitHub

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.

Any agent
npx skills add Jeffallan/claude-skills --skill spec-miner
Clone the repo
git clone --depth 1 https://github.com/Jeffallan/claude-skills

Made for: Claude Code.

Or install fullstack-dev-skills, the plugin that ships this one along with the rest of its 57 skills.

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-miner

README.md
[![agentmods](https://agentmods.dev/badge/skills/jeffallan/claude-skills/spec-miner/github.svg)](https://agentmods.dev/skills/jeffallan/claude-skills/spec-miner)
Your own site
<a href="https://agentmods.dev/skills/jeffallan/claude-skills/spec-miner"><img src="https://agentmods.dev/badge/skills/jeffallan/claude-skills/spec-miner/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.

agentmods 80×15 button for spec-miner

Your own site · 80×15
<a href="https://agentmods.dev/skills/jeffallan/claude-skills/spec-miner"><img src="https://agentmods.dev/badge/skills/jeffallan/claude-skills/spec-miner.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 100 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 988 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Socket pass 30 Apr 2026
  • Snyk pass 30 Apr 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00100 $0.00988
Opus 5 $0.00050 $0.00494
Sonnet 5 $0.00020 $0.00198
Haiku 4.5 $0.00010 $0.00099

Measured 12d ago against content hash 0deb55afcc6c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

spec-miner 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 12d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

skills/spec-miner/SKILL.md · 111 lines

How it starts

The opening of the file, as written. The whole thing — 111 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Spec Miner

Reverse-engineering specialist who extracts specifications from existing codebases.

Role Definition

You operate with two perspectives: Arch Hat for system architecture and data flows, and QA Hat for observable behaviors and edge cases.

When to Use This Skill

  • Understanding legacy or undocumented systems
  • Creating documentation for existing code
  • Onboarding to a new codebase
  • Planning enhancements to existing features
  • Extracting requirements from implementation

Core Workflow

  1. Scope - Identify analysis boundaries (full system or specific feature)
  2. Explore - Map structure using Glob, Grep, Read tools
    • Validation checkpoint: Confirm sufficient file coverage before proceeding. If key entry points, configuration files, or core modules remain unread, continue exploration before writing documentation.
  3. Trace - Follow data flows and request paths
  4. Document - Write observed requirements in EARS format
  5. Flag - Mark areas needing clarification

Example Exploration Patterns

# Find entry points and public interfaces
Glob('**/*.py', exclude=['**/test*', '**/__pycache__/**'])

# Locate technical debt markers
Grep('TODO|FIXME|HACK|XXX', include='*.py')

# Discover configuration and environment usage
Grep('os\.environ|config\[|settings\.', include='*.py')

# Map API route definitions (Flask/Django/Express examples)
Grep('@app\.route|@router\.|router\.get|router\.post', include='*.py')

EARS Format Quick Reference

EARS (Easy Approach to Requirements Syntax) structures observed behavior as:

Type Pattern Example
Ubiquitous The <system> shall <action>. The API shall return JSON responses.
Event-driven When <trigger>, the <system> shall <action>. When a request lacks an auth token, the system shall return HTTP 401.
State-driven While <state>, the <system> shall <action>. While in maintenance mode, the system shall reject all write operations.
Optional Where <feature> is supported, the <system> shall <action>. Where caching is enabled, the system shall store responses for 60 seconds.

Read the full file on GitHub · 111 lines

Files

What ships with it

4 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.

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. 12d ago First seen · 111 lines · 100 tokens per session scan A 0deb55afcc6c

Subscribe to this mod's changes

spec-miner is a skill published in the GitHub repository Jeffallan/claude-skills (11,426 stars, last pushed 1mo ago), licensed MIT. It adds 100 tokens to every session and 988 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.