Spec Miner

What it does

When your agent uses it

• Getting up to speed on an inherited project with no documentation
• Documenting what an old module actually does
• Extracting requirements from implementation before a rewrite
• Onboarding to a new codebase
• Planning changes to an existing feature

Example prompts

• “Explore the billing module and write up its behavior as EARS requirements.”
• “Map the entry points and data flows of this inherited Python service.”
• “There are no docs for the import job, so figure out what it does and list what is unclear.”
• “Create an architecture overview of this repository from the code itself.”

Requirements

• Pre-approved tools (allowed-tools): Read, Grep, Glob

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

1. 1Scope - Identify analysis boundaries (full system or specific feature)
2. 2Explore - Map structure using Glob, Grep, Read tools
3. 3Trace - Follow data flows and request paths
4. 4Document - Write observed requirements in EARS format
5. 5Flag - Mark areas needing clarification

What it can do on your machine

Read from SKILL.md and the folder at commit 1be15d8. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Grep
  • Glob

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md.

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • github.com
  • synergetic.solutions
  • jeffallan.github.io

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Spec Miner loads about 1.2k tokens when it runs, and up to ~3.1k if it reads all its reference files. Until then it costs about 146 tokens; SKILL.md has 362 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~146

When it runs · the whole SKILL.md, loaded when a task matches

~1.2k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~3.1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from Jeffallan/claude-skills at commit 1be15d8, republished under its MIT licence (© Jeffallan). 362 words, ~1,192 tokens.

name

spec-miner

description

Reverse-engineering specialist that extracts specifications from existing codebases. Use when working with legacy or undocumented systems, inherited projects, or old codebases with no documentation. Invoke to map code dependencies, generate API documentation from source, identify undocumented business logic, figure out what code does, or create architecture documentation from implementation. Trigger phrases: reverse engineer, old codebase, no docs, no documentation, figure out how this works, inherited project, legacy analysis, code archaeology, undocumented features.

allowed-tools

Read, Grep, Glob

license

MIT

metadata.author

https://github.com/Jeffallan

metadata.company

https://synergetic.solutions

metadata.version

1.1.0

metadata.domain

workflow

metadata.triggers

reverse engineer, legacy code, code analysis, undocumented, understand codebase, existing system

metadata.role

specialist

metadata.scope

review

metadata.output-format

document

metadata.related-skills

feature-forge, fullstack-guardian, architecture-designer

# 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')

© Jeffallan, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 4 other files (references) in skills/spec-miner of Jeffallan/claude-skills.

• SKILL.md
• references/analysis-checklist.md
• references/analysis-process.md
• references/ears-format.md
• references/specification-template.md

Open the folder on GitHubat commit 1be15d8