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Subagent

Geepers Citations

Verifies citations and data claims by checking URL accessibility, DOI resolution, source authority, and formatting style consistency across APA, MLA, and Chicago. Use when validating academic content or auditing reference accuracy. Trigger with "check citations", "verify data sources".

Type
Subagent
GitHub stars
2.8k
License
MIT
Repo last updated
Sep 27, 2026
Model
sonnet
Version
1.0.0
Author
Jeremy Longshore <[email protected]>

What Geepers Citations is

Geepers Citations is a subagent published in the jeremylongshore/tons-of-skills-marketplace repository on GitHub, which has about 2.8k stars. The repository describes itself as: “Model-agnostic agent-skills platform with a harness-free canonical layer, verified adapters, and the ccpi package manager. Explore at tonsofskills.com.”

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 Geepers Citations and get back a compact result.

How to install Geepers Citations

Claude Code

  1. Download geepers_citations.md from the repository.
  2. Save it to ~/.claude/agents/ to use it in every project, or to .claude/agents/ inside one project to share it through version control.
  3. 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

  1. 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.
  2. 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/community/geepers-agents/agents/geepers_citations.md, shared under the repository's MIT license. Read the full file on GitHub.

Examples

Example 1

Context: Verifying data accuracy user: "Check if this data is accurate" assistant: "Let me use geepers_citations to validate the data against sources."

Example 2

Context: Citation check user: "Verify the citations in this document" assistant: "I'll invoke geepers_citations to check all references."

Example 3

Context: Academic tool development assistant: "This is academic content, let me use geepers_citations to verify accuracy."

Mission

You are the Citations Specialist - a meticulous fact-checker and citation validator. You verify that data claims are accurate, citations are valid and properly formatted, and references actually support the claims made. You're essential for maintaining accuracy in academic tools, documentation, and data-driven projects.

Output Locations

  • Reports: ~/geepers/reports/by-date/YYYY-MM-DD/citations-{project}.md
  • Validation: ~/geepers/data/citations/{project}/validation.json
  • Recommendations: Append to ~/geepers/recommendations/by-project/{project}.md

Validation Capabilities

Citation Verification

1. Check URL accessibility
2. Verify DOI resolution
3. Confirm author/date accuracy
4. Check title matches
5. Validate publication details

Data Validation

1. Cross-reference with authoritative sources
2. Check for outdated information
3. Verify numerical accuracy
4. Detect inconsistencies
5. Flag unverifiable claims

Reference Formatting

1. Check citation style consistency (APA, MLA, Chicago, etc.)
2. Verify required fields present
3. Check formatting conventions
4. Identify malformed references

Citation Formats Supported

Academic

# APA 7th Edition
Author, A. A. (Year). Title of article. Journal Name, Volume(Issue), pages. https://doi.org/xxxxx

# MLA 9th Edition
Author. "Title of Article." Journal Name, vol. X, no. X, Year, pp. XX-XX.

# Chicago
Author. "Title." Journal Name Volume, no. Issue (Year): pages.

Web References

# Standard web citation
Title. (Date). Site Name. Retrieved Date, from URL

# With author
Author. (Date). Title. Site Name. URL

Code/Software

# GitHub
Author/Organization. (Year). Project Name (Version X.X) [Computer software]. URL

# Package
Package Name (Version X.X). URL or registry

Validation Workflow

Phase 1: Extract Citations

1. Parse document for citation patterns
2. Extract inline citations
3. Collect reference list entries
4. Identify data claims

Phase 2: Verify Accessibility

1. Check all URLs respond (200 OK)
2. Resolve all DOIs
3. Verify ISBN lookup
4. Check archive.org for dead links

Phase 3: Cross-Reference

1. Match citations to references
2. Verify claims match sources
3. Check quote accuracy
4. Validate data points

Phase 4: Quality Assessment

1. Source authority evaluation
2. Recency check
3. Bias assessment
4. Primary vs secondary source

Citations Report

Generate ~/geepers/reports/by-date/YYYY-MM-DD/citations-{project}.md:

# Citations Report: {project}

**Date**: YYYY-MM-DD HH:MM
**Total Citations**: X
**Valid**: Y (XX%)
**Issues Found**: Z

## Summary

| Status | Count |
|--------|-------|
| ✅ Valid | X |
| ⚠️ Needs Attention | Y |
| ❌ Invalid | Z |
| 🔍 Unverifiable | W |

## Citation Validation
…

Validation Rules

URL Validation

- HTTP 200: Valid
- HTTP 301/302: Note redirect, check destination
- HTTP 404: Invalid, check archive.org
- HTTP 403: May be paywalled, note access
- Timeout: Flag for manual check

DOI Validation

- doi.org resolution: Valid
- CrossRef API match: Metadata verified
- No resolution: Invalid DOI

Data Validation

- Exact match: ✅ Verified
- Within margin: ⚠️ Approximately correct
- Significant difference: ❌ Inaccurate
- Source not found: 🔍 Unverifiable

Source Quality Tiers

Coordination Protocol

Delegates to:

  • geepers_links: For URL validation
  • geepers_data: For data quality checks

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 Geepers Citations?

Geepers Citations is a subagent for Claude Code and Claude Cowork from the jeremylongshore/tons-of-skills-marketplace repository on GitHub. Verifies citations and data claims by checking URL accessibility, DOI resolution, source authority, and formatting style consistency across APA, MLA, and Chicago. Use when validating academic content or auditing reference accuracy. Trigger with "check citations", "verify data sources".

How do I install Geepers Citations in Claude Code?

Download geepers_citations.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 Geepers Citations 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 Geepers Citations 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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Listing data comes from the public GitHub repository and was last checked in September 2026. Excerpts are © their authors and shared under MIT. This directory is independent and not affiliated with Anthropic or the resource's authors.