Run Chain-of-Verification (CoVe) on a draft or a block of text with factual claims. Spawns the `claim-verifier` agent in a forked (fresh) context so it never sees the draft — then reports which claims are supported, contradicted, or unverifiable. Use when user says "verify these citations", "check the claims in X", "did I hallucinate anything", "fact-check this draft", "run CoVe on this", or after any text generation that asserts facts about papers, datasets, or numerical results. NOT for style/grammar review (use `/proofread`) or substance review (use `/review-paper`).
Fact-check a draft using the Post-Flight Verification protocol (.claude/rules/post-flight-verification.md).
Input: $ARGUMENTS — path to a file containing the draft (markdown, .qmd, .tex, .md) or a shorthand pointer. Optional flags:
--source <path-or-url> — one or more source-material pointers (repeat for multiple). If omitted, the skill infers from context (e.g., papers referenced, cited arXiv URLs).--no-fail-closed — downgrade FAIL outcomes to warnings without regeneration. Use sparingly./verify-claims (this skill) — ad-hoc fact-checking on any draft or text block the user hands you. One-shot, user-invoked./lit-review, /research-ideation, /respond-to-referees, ) — no need to call this separately; they already run it./review-paper --peer/proofread — grammar, typos, overflow. Different lens./review-paper (default mode) — full manuscript review, not just claim verification.Implements the 4-step CoVe loop from Dhuliawala et al. 2023 (arXiv:2309.11495), with architectural enforcement of the fresh-context independence trick.
Confirm:
--source or auto-detected from draft)claim-verifier agent file exists at .claude/agents/claim-verifier.mdIf any fail → surface the failure, do NOT proceed.
Read the draft. Identify factual assertions of these types:
| Type | Example |
|---|---|
| Citation | "Smith (2019, JEL) shows X" |
| Numerical fact | "N = 10,000", "ATT = 0.42" |
| Negative literature | "No prior work studies X" |
| Named entity | researcher, paper title, venue, package, estimator name |
| Dataset claim | "The CPS contains field educ_attain" |
Skip: opinions, forward-looking suggestions, definitions the draft introduces.
Output a claims table:
| ID | Claim | Source hint |
|----|-------|-------------|
| C1 | ... | ... |
One question per claim. Make it specific and answerable from the source alone.
claim-verifier (forked, fresh context)Task: subagent_type=claim-verifier, context=fork
Prompt: hand over claims table + verification questions + source material pointers.
Do NOT include the draft text.
The forked agent runs the CoVe independent-answer step. It has never seen the draft and cannot confirm-bias. It returns a structured verification report.
Based on the report:
Respect --no-fail-closed: on FAIL, produce the warning but do not regenerate.
/verify-claims quality_reports/lit-review_staggered-did.md --source master_supporting_docs/callaway_santanna_2021.pdf --source master_supporting_docs/dechaisemartin_dhaultfoeuille_2020.pdf
Expected output (abridged):
## Post-Flight Verification — lit-review_staggered-did.md
**Claims extracted:** 14
**Verified independently:** 14 (forked claim-verifier)
**Outcome:** PARTIAL — 12 verified, 1 discrepancy, 1 unverifiable
### Discrepancies
- **C7** — draft claims "de Chaisemartin & D'Haultfœuille (2020) *propose* a DR estimator." Source Section 4 shows they propose a weighting estimator, not DR. Recommend correction.
### Unverifiable
- **C12** — draft cites "Borusyak et al. 2024 (working paper)". No canonical URL in provided sources. Recommend user supply DOI or arXiv link.
### Verified
| ID | Claim | Evidence |
|----|-------|----------|
| C1 | "Callaway & Sant'Anna 2021 use group-time ATT" | p. 5, eq. (3) |
| ... | ... | ... |
Verifier times out: surface a warning block, return draft as provisional. Do not silently ship.
Source material inaccessible (paywall, 404): report the specific claims that hinge on it, flag as cannot-verify, recommend user supply an alternative source.
Draft contains only opinions / forward-looking text: report "no verifiable factual claims extracted — nothing to check" and return.
.claude/agents/claim-verifier.md — the forked verifier..claude/rules/post-flight-verification.md — the protocol.[LEARN:pattern] on Chain-of-Verification vs critic-fixer vs cross-artifact review.