Citation Verifier

Overview

Use this skill when citation integrity is the bottleneck. It is narrower and more operational than general writing skills: the goal is to catch unverifiable references, missing identifiers, duplicated BibTeX keys, placeholder citations, and mismatches between local citation artifacts before they become submission problems.

Use this skill together with scientific-writing or submission-audit, not instead of them.

When To Use

Use this skill when:

• a manuscript is close to submission or resubmission
• the bibliography may contain placeholders, guessed entries, or stale metadata
• a .bib file needs a hygiene pass
• the draft mixes DOI, arXiv, PMID, or plain-text references inconsistently
• you need to verify that local citation artifacts are ready before manual or online source verification

Do not use this skill for:

• generic literature discovery from scratch
• full manuscript restructuring
• venue formatting that does not depend on citation integrity

Local First Pass

Start with a local citation scan before any online verification.

The helper script:

python ~/.codex/skills/citation-verifier/scripts/scan_citations.py path/to/file_or_dir [...]
# Claude Code (global install): replace ~/.codex/skills with ~/.claude/skills
# Claude Code (project-local install): replace ~/.codex/skills with .claude/skills

Use it to find:

• [CITATION NEEDED] or similar placeholders
• PLACEHOLDER_... citation keys
• TODO: verify markers
• DOI, arXiv, and PMID tokens
• LaTeX \cite{...} keys
• duplicate BibTeX keys inside .bib files

Treat imported BibTeX and Google Scholar-style exports as draft metadata, not as verified truth.

Verification Order

1. Scan the local draft and bibliography artifacts.
2. Remove or flag all placeholder citations.
3. Check BibTeX-key uniqueness and obvious identifier gaps.
4. Normalize metadata fields that are commonly wrong in copied BibTeX:
   • author list and spelling
   • year
   • venue or journal name
   • volume, issue, pages, or article number
   • DOI versus preprint identifier
5. For every citation that matters to a scientific claim, verify the paper exists in trusted sources.
6. If a claim depends on a specific result, confirm the cited paper actually supports that claim.
7. Only then finalize formatting for the venue.

Trusted Verification Sources

Prefer this order when moving beyond local scans:

• publisher page or DOI resolver
• PubMed for biomedical papers
• arXiv for preprints
• Crossref or Semantic Scholar for metadata cross-checking
• Google Scholar only as a fallback discovery aid, not as the sole source of truth

Common Failure Modes

• writing BibTeX from memory
• leaving placeholder citation keys in the draft
• assuming an arXiv preprint and published version are interchangeable
• citing a paper correctly but using it to support a claim it does not make
• letting duplicate BibTeX keys silently overwrite entries
• blindly trusting copied Scholar or BibTeX metadata for venue names, pages, years, or DOI fields

Output Standard

When using this skill, report:

• placeholder or unverifiable items
• duplicate or suspicious BibTeX keys
• missing or inconsistent DOI/arXiv/PMID information
• suspicious metadata fields that need manual correction
• claims that still need source verification
• the minimum safe next step before submission