Extractor
Autonomous knowledge extraction agent. Analyzes codebase structure, business logic, data flows, and patterns to build the gauntlet knowledge base.
- Type
- Subagent
- Repository
- athola/claude-night-market
- GitHub stars
- 339
- License
- MIT
- Repo last updated
- Sep 24, 2026
- Source file
- plugins/gauntlet/agents/extractor.md
- Model
- sonnet
What Extractor is
Extractor is a subagent published in the athola/claude-night-market repository on GitHub, which has about 339 stars. The repository describes itself as: “23 Claude Code plugins: TDD enforcement hooks, git/PR workflows, spec-driven development, code review, project lifecycle, fix-from-error, maintenance automation, context optimization, research, and multi-LLM delegation. 186 skills, 128 commands, 54 agents.”
A subagent is a specialist assistant that Claude can hand part of a task to. It is a markdown file whose frontmatter sets a name, a description that tells Claude when to delegate, and optionally the tools and model it may use; the body becomes the subagent's own system prompt.
Because a subagent works in its own context, it keeps the main conversation focused: Claude can send a narrow job, such as a review or a specialised analysis, to Extractor and get back a compact result.
How to install Extractor
Claude Code
- Download extractor.md from the repository.
- Save it to ~/.claude/agents/ to use it in every project, or to .claude/agents/ inside one project to share it through version control.
- Claude Code watches these folders, so the subagent is usually available right away. Ask Claude to use it by name, or @-mention it to make sure it runs.
Claude Cowork
- Cowork loads subagents through plugins. If the repository is packaged as a plugin marketplace, add it under Customize → Plugins → Add marketplace and install the plugin that contains this subagent.
- Otherwise, bundle the file into your own plugin's agents/ folder and upload it from Customize → Plugins.
New to extending Cowork? Our plugins guide and Customize guide explain how skills, plugins, and connectors fit together.
Inside the source file
An excerpt from plugins/gauntlet/agents/extractor.md, shared under the repository's MIT license. Read the full file on GitHub.
Analyze a codebase and produce .gauntlet/knowledge.json.
Workflow
- Discover source files via Glob (skip tests, configs, generated)
- Run AST extraction:
python3 plugins/gauntlet/scripts/extractor.py <target-dir> \
--output .gauntlet/knowledge.json- Enrich entries: read source files and enhance detail with business logic, data flow, and architectural context
- Cross-reference: link entries that share files in related_files
- Assign categories (priority: business_logic > architecture > data_flow > api_contract > pattern > dependency > error_handling)
- Validate: non-empty detail, valid difficulty (1-4), at least one tag
- Save to .gauntlet/knowledge.json
Error Handling
- Skip unparseable files, log warning
- Fall back to Read + Grep if script fails
- Report partial results rather than failing entirely
Before you install
- Read the whole file first. Skills, commands, and subagents are instructions Claude will follow, so make sure they match what you want.
- Check which tools, scripts, or MCP servers it uses. Local servers and scripts run with your permissions.
- Try it in a test project or a copy of your files before pointing it at real work.
- Pin the version you tested, and review changes before updating.
- Watch for instructions that fetch web content or run shell commands; those are where prompt injection risks start. See our prompt injection guide.
FAQ
What is Extractor?
Extractor is a subagent for Claude Code and Claude Cowork from the athola/claude-night-market repository on GitHub. Autonomous knowledge extraction agent. Analyzes codebase structure, business logic, data flows, and patterns to build the gauntlet knowledge base.
How do I install Extractor in Claude Code?
Download extractor.md from the repository. Save it to ~/.claude/agents/ to use it in every project, or to .claude/agents/ inside one project to share it through version control. Claude Code watches these folders, so the subagent is usually available right away. Ask Claude to use it by name, or @-mention it to make sure it runs.
Can I use Extractor in Claude Cowork?
Cowork loads subagents through plugins. If the repository is packaged as a plugin marketplace, add it under Customize → Plugins → Add marketplace and install the plugin that contains this subagent. Otherwise, bundle the file into your own plugin's agents/ folder and upload it from Customize → Plugins.
Is Extractor safe to install?
It is a third-party community resource, not reviewed by Anthropic or this site. Read the source file first, check which tools and connectors it uses, and install only from sources you trust.
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