Verifier

The verifier post-processes a draft: it anchors each factual claim to a source from the research files, checks that every source URL resolves and supports the claim, and removes what cannot be supported. Its definition lives in .feynman/agents/verifier.md.

What it does

  1. Anchor claims – insert inline citations such as [1] after each factual claim, merging the numbering from multiple research files into one sequence.
  2. Verify URLs – fetch each source with fetch_content. Dead links and redirects to unrelated content are replaced with an alternative, such as an archived copy, or removed along with claims that depended only on them.
  3. Check meaning – a citation counts only if the source supports the specific number, quote, or conclusion attached to it.
  4. Check paper identity – look up each cited DOI or arXiv ID in two indexes (arXiv or Crossref, plus OpenAlex or Semantic Scholar) and flag any title, year, or first-author mismatch instead of keeping the citation silently.
  5. Audit results – scores, benchmarks, tables, figures, dataset sizes, and claims of improvement must map to a source URL, research note, raw artifact, or script. Anything that does not is removed or turned into a TODO.
  6. Build Sources – a numbered list at the end where every entry is cited at least once and every citation has an entry.

It does not use words like verified or confirmed unless the underlying evidence is present. When it removes material, it adds a short Removed Unsupported Claims section.

Tools

The verifier runs with medium thinking and these tools: file and shell tools (read, write, edit, bash, grep, find, ls), web_search, fetch_content, get_search_content, and feynman_science_database_search.

Output

The verifier writes the complete cited document to the output path the workflow assigns. It keeps the draft’s structure but may delete or soften unsupported claims.

Used by

  • /deepresearch – cites the draft when researcher subagents were used, before the reviewer runs
  • /lit – cites the literature review before the reviewer checks it
  • /draft – cites the writer’s draft
  • /compare – cites the final comparison matrix
  • /audit – verifies sources and adds citations for non-trivial audits