Grounded Citations

Every claim taken from an outside source gets an inline numbered citation and a Sources: list, Perplexity-style. A ledger script owns the url → [n] mapping so the numbers and URLs come from retrieval, never from memory — the model only ever emits small integers it was handed.

For high-stakes work the same ledger doubles as a fact-checking chain: verbatim quotes are attached to each source (rejected unless they literally appear in the fetched page text), claims from model knowledge are flagged [unverified], and verify --evidence fails any draft whose cited sources carry no evidence.

This skill covers answers in chat, written documents (markdown, PDF, docx, slides), and research reports. It does not cover academic BibTeX pipelines — for conference papers use the research-paper-writing skill, which this skill feeds (see references/citation-formats.md).

When to Use

Use whenever an answer or artifact rests on information you fetched rather than knew:

• Research, comparisons, news summaries, "what is the current state of X"
• Any deliverable you write to disk that quotes, paraphrases, or reports outside facts — reports, briefs, docs, decks, wiki pages
• Fact-finding where the user will want to check your work
• Multi-source synthesis where conflicting sources must be attributed

Skip inline citations when the retrieval is incidental to another task — a quick syntax/version lookup mid-coding, casual conversation, creative writing. Mention a URL only if the user would plausibly want the link.

Prerequisites

None beyond the standard toolset. scripts/sources.py is stdlib-only Python 3. Retrieval comes from whatever is configured: web_search, web_extract, browser_navigate, or terminal (curl, CLIs).

Ledger location: $HERMES_HOME/cache/citations/ledger.json (profile-aware). Override per task with --ledger <path> or HERMES_CITATION_LEDGER.

How to Run

S=~/.hermes/skills/research/grounded-citations/scripts/sources.py

python3 "$S" reset                                  # start a clean ledger
python3 "$S" add https://example.com/a --title "A"  # prints: [1]
python3 "$S" add https://example.com/b --title "B"  # prints: [2]
python3 "$S" list                                   # ledger table
python3 "$S" render                                 # Sources: block
python3 "$S" verify draft.md                        # catch bad citations

add is idempotent and URL-normalized: the same page always returns the same id within a ledger, so ids stay stable across many search/extract rounds.

Quick Reference

Procedure

① Reset the ledger at the start of a task that will produce a grounded answer or document. Skip the reset when continuing work whose ids are already in a draft — reusing the ledger keeps the numbering stable.

② Register every source at retrieval time. After each web_search / web_extract / browser_navigate / fetch, pass the URLs to sources.py add (or pipe the raw JSON through sources.py ingest). Do this before writing prose. Registering later, from memory, is the failure mode this skill exists to prevent.

③ Write cite-while-drafting. Place the bracketed id(s) immediately after each sentence the source supports:

Ice floats because it is less dense than liquid water.[1][2]

• No space before the bracket; each id in its own brackets.
• Max 3 ids per sentence. Cite per sentence, not one dump at the end.
• Only ids the ledger returned. Never invent an id or a URL.
• Claims from your own knowledge get no citation.
• Conflicting sources: present both readings, each with its own id.
• Quote exact figures, dates, and names as the source states them; flag gaps explicitly ("no source found for X") instead of smoothing them over.

④ Append the Sources block with sources.py render --cited-in <draft> so the id → URL mapping is generated mechanically from the ledger, not retyped. For non-markdown targets pick the matching --style and follow references/citation-formats.md for placement (footnotes in docx, endnotes in PDF/LaTeX, a Sources slide in decks, per-page source lists in wiki output).

⑤ Verify before delivering — sources.py verify <draft> exits non-zero on unknown ids, on a Sources block that disagrees with the ledger, or (with --min-coverage) on prose that is too thinly cited. Fix and re-run.

⑥ Chat answers follow the same steps with the draft in your reply: register sources, cite inline, end with the rendered Sources: list. For a short answer you may render the block from sources.py render --only <ids> instead of writing to a file.

Fact-Checking Mode

For work where the reader must be able to check the chain — medical, legal, financial, safety, disputed claims, or when the user asks for fact-checking — upgrade from citations to evidence:

① Attach a verbatim quote per source. After extracting a page, save its text to a file and attach the sentence(s) that carry each claim:

python3 "$S" quote 1 --text "Ice is about 9% less dense than liquid water." --from page1.txt

The quote is rejected unless it appears verbatim in the evidence text (insensitive to whitespace, case, and markdown markup — inline links like _[ERAP1](https://…)_ in extracted text match the plain prose a reader sees), so a paraphrase or misremembered figure cannot masquerade as evidence. Copy-paste from the fetched text; never retype. Quote the sentence as the reader sees it — the matcher sees through the extractor's markup for you, so you don't have to reproduce link syntax or escaped asterisks in your quote.

② Flag model-knowledge claims with [unverified]. A load-bearing claim you could not source gets an explicit marker instead of a citation:

The refactor likely predates the 2.0 release.[unverified]

verify --min-coverage counts [unverified] sentences as covered — the goal is declared provenance for every claim, not a citation on every sentence. If a key claim can be checked, check it; [unverified] is for what genuinely cannot be, and a fact-check deliverable dominated by [unverified] markers should say so in its summary.

③ Cross-check disputed facts against a second independent source. When two sources disagree, cite both readings with their own ids and quotes, and say which you weight and why. One source is reporting; two independent sources are corroboration.

④ Verify with the evidence gate and render the evidence block:

python3 "$S" verify report.md --evidence --min-coverage 0.5
python3 "$S" render --style evidence --replace-in report.md

--evidence fails the draft if any cited source has no attached quote. The evidence render style prints each source's quotes beneath its URL, so the deliverable shows claim → source → exact supporting text with nothing taken on faith. Use --replace-in <draft> to rewrite an existing Sources block in place (idempotent — safe to re-run after attaching more quotes); --cited-in prints to stdout instead. Both emit the heading ## Sources (--style plain emits Sources:).

What --min-coverage counts. Coverage is sentences with declared provenance / prose sentences. A prose sentence is a non-empty line fragment of 4+ words after the Sources block, headings (#), table rows (|), and fenced code are dropped; blockquote markers are stripped. Provenance is declared by either a [n] citation or an [unverified] marker, so a sentence carrying both counts once. Run verify without a threshold first and read the info: stats: line to see the counts before picking a number.

Pitfalls

• Registering after writing. The ledger must be populated from tool output, not reconstructed from the draft — that reintroduces exactly the hallucinated -URL risk the numbering removes.
• Renumbering mid-task. Never hand-edit ids in a draft. Ids are ledger identities; if a draft cites [4], [4] must stay that source. Run reset only between tasks.
• Retyping URLs into the Sources block. Always render. A hand-typed URL is an unverified claim.
• Citing a search snippet as if you read the page. A web_search description supports only what it literally says. Cite the extracted page when the claim needs the body — web_extract it first.
• Over-citing. Three ids on a sentence is the ceiling; a citation on every clause makes text unreadable and hides which source carries the load.
• Citing the ledger in code/config artifacts. Source comments belong in prose deliverables and doc headers, not inside generated code.
• Parallel subagents. Each subagent has its own working directory; point them all at one ledger with --ledger (or HERMES_CITATION_LEDGER) if their outputs get merged, otherwise their ids will collide.
• Quoting from a snippet instead of the page. Evidence quotes must come from the extracted page text, not a search-result description — web_extract first, save the text, then quote --from that file.
• Paraphrasing into quote --text. The verbatim check will reject it; the fix is to find the actual sentence, not to reword until something matches.
• Using [unverified] as an escape hatch. It marks the rare claim that genuinely cannot be sourced; if most sentences carry it, the task needed more retrieval, not more markers.
• Hand-editing the Sources block. Use render --replace-in <draft>; slicing the file yourself risks a stale or duplicated block that verify then flags.

Verification

python3 "$S" verify report.md --strict --min-coverage 0.5

Green means: every [n] in the draft exists in the ledger, the Sources block lists exactly the cited ids with the ledger's URLs, and the cited share of source-bearing sentences meets the threshold. Read the warnings even when the exit code is 0 — uncited registered sources usually mean a claim lost its attribution during editing.