Research

Answer the caller's bounded question with cited evidence. Choose ordinary investigation, claim checking, decision lineage, repository tracing or pattern evidence according to the question; these are optional modes, not a sequence. A quick answer needs no report file. Plan owns unified discovery and resumption when the question is part of shaping a change; return this cited answer to that existing intent without restarting its interview or taking over caller choices.

Evidence rules

• One lineage counts once. Copies, ports and repeated quotations of one upstream source are a single exemplar, however many files or reports carry them. Check provenance before counting instances as independent, and stop searching once new queries return only sources already read.
• Separate the invariant from the incidental. Align instances by their role in the behavior; name what must hold, what legitimately varies and what is incidental syntax. An instance missing the invariant is not an instance.
• Recurrence does not earn a gate. A blocking check needs a demonstrated cost of violation: an incident, defect or measured harm traced to the pattern's absence. Recommend the least committed useful shape: no action, a reference or checklist line, a template, a helper, and only then a gate.
• Thin evidence stays a hypothesis. Fewer than three independent exemplars, or no passing holdout, leaves a pattern a hypothesis; say what evidence would confirm or refute it.
• Keep observation, inference, contradiction and unknown separate. Every material claim cites evidence; a claim taken from a document or report cites a passage that asserts it, not one that only discusses the topic, else mark it unsupported. Say when a decisive claim rests on one source; agreement does not erase shared provenance.
• A call is not the callee's behavior. Seeing code call retry, validate or a service shows only that the call happens. Before a claim relies on what the callee guarantees (retried, atomic, idempotent, ordered, durable), read its implementation or tests, or an external service's published contract; otherwise mark the guarantee unknown in the claim itself, not in a later caveat.
• A search that found nothing proves absence only if it could have matched. Before saying something does not exist or is unused, check the search's exit status and error output, whether results were truncated, whether ignore rules or default filters skipped relevant paths (ignored, hidden, vendored or generated files), and that the intended ref or tree was searched rather than a stale index. Where cheap, confirm the same search finds a term known to be present. A failed or mis-scoped search is an unknown with its cause, not "none found". For "unused" or "nothing calls this", text search also misses re-exports, aliases, reflection, string-keyed dispatch, dependency injection, generated code and outside consumers; prefer the host's references-aware tool when it has one, and name which of these remain unchecked.

Investigation

1. State the question and the decision it informs. Reuse the accepted scope and identify what evidence would answer it; do not expand the objective mid-search. Use the subject, range and sources the caller named. Report an empty range, a missing subject or an unreachable named source as such instead of answering about an adjacent one; name any substitute the caller allowed.
2. Inspect the smallest relevant sources and verify search hits against the actual source. External facts that change (versions, vendor behavior, standards) need current primary sources. This skill pre-approves only local tools: use the host's web tools when available and permitted; otherwise mark the external claim unknown and name the source that would settle it. Before an external search or outside service sees a query, strip host names, IP addresses, file paths, query fragments, account or customer identifiers and internal names; search on the generic error class with the library and version. If no safe form remains, skip the external lookup and say so. For how a third-party library, tool or service behaves here, first find the version this repository actually resolves: its lockfile, the installed binary's reported version or a vendored copy. Answer from that version's source, tests or release notes. Latest documentation, web answers and recall are leads; say so when they describe a different version. Before recommending an external API, SDK, auth scope or service, look for deprecation, sunset and breaking-change notices for the version being recommended and state any in the answer; without a permitted lookup, say that status is unchecked.
3. Lead with the answer, then show evidence and remaining gaps. Each part of the question is answered or explicitly unknown with the searched scope disclosed. Before settling a consequential answer, look once for the strongest contrary evidence. When the caller asked for an explanation, write for their level in plain words and mark which reasons are documented, which are your inference and which are unknown.

Code claims cite the observed commit plus file:line. For uncommitted content, state HEAD and the changed-file status; do not claim the working bytes can be replayed from HEAD. Keep source identity and freshness visible. Search output, CASS, MS and prior reports are leads, not authority or required phases. Use the current agent by default; additional readers and runtimes require caller selection or existing authorization.

For several supplied reports, retain each source's identifier, author/runtime when known and revision/date. Compare claims as agreement, contradiction or unknown while preserving their original evidence. Verify decisive claims at their source and return one synthesis; do not launch recursive synthesis passes.

Claim checking

To check whether a draft, report or answer is true, split it into atomic claims a source could confirm or refute. Opinions and predictions are not checked; say so. Check first what would mislead most: numbers, quotations, attributions, superlatives and the claims the conclusion rests on. Recall from training is a lead, never the source.

• Re-derive, do not re-read. A claim produced from data (a query, a script, a repository count) is checked through a different path: another query, a different key or grouping, or the underlying files themselves. Re-running the producer repeats its mistake, and a report's own numbers are not evidence for that report.
• Association is not authorship. "X wrote, decided or caused Y" needs a statement or record of exactly that relation. Appearing in the same commit, meeting or document is weaker evidence; report it as such.
• Return each claim as supported, contradicted, unsupported or not checkable, with its citation and the path used. Corrections are proposals; editing the checked document belongs to Doc.

Adoption questions

For "should we adopt, replace or keep X" or "does advisory Y reach us", the answer needs both sides. Ours: the current tool and a cited place it is used, or a searched absence plus where X would plug in, and any earlier decision on the same question. Theirs: a current primary source for each external fact the answer rests on. Where relevant, also cover the fit, license, cost-of-staying and maintenance facts in adoption evidence. A strong side never covers a missing one; then answer "not yet answerable" and list what to inspect. Keeping the current tool or doing nothing is a real option. "Does not reach us" states the search and its scope. For a choice that is costly to undo, each decisive claim needs two independent sources. A claim made in the conversation is a lead to check, not evidence. Rank candidates for "what should we use for X" only when they are a short list found in current sources and the criteria are stated or recoverable; otherwise return what was found and name what is missing, leaving criteria to the caller and an open field to Idea Genie.

Decision lineage

For "why is it like this" or "how did this idea change", trace one decision or idea through its record: commits, ADRs, issues, reviews and prior reports. Separate its first appearance, clearest statement, current form, reversals, contradictions (two claims that cannot both hold) and abandoned variants, each dated and cited. A bucket with no evidence says what was searched. Do not smooth sparse or messy history into a tidy story; a supersession is not a contradiction. Before presenting a past reason as a binding constraint, check that its cause still holds in the current tree or record; if it no longer holds, report that as evidence for reopening the decision; whether it still binds stays with its owner or the caller.

Repository tracing

For a repository model or audit, start from its declared entry points in docs, build manifests or command help and verify them against executable paths. Follow a relevant flow through entry, domain logic, integration and tests; prefer a completed trace to a shallow directory inventory. Report an interrupted trace at its exact file/line and explain what is missing. Choose a useful lens such as persistence, authorization, CLI, build or test without requiring a sweep of every lens. In any trace, a how-it-works answer included, say what each step reads or changes and keep the error and edge branches the question depends on, not only the success path. Source and tests establish behavior; a file name or a claim in the conversation does not.

An inline investigation may use dirty working-tree evidence with explicit limits. A selected durable codebase-recon.v1 pack is commit-bound and follows the recon pack contract, checked by skills/research/scripts/codebase-recon/validate-output.sh.

Pattern evidence

For a recurring implementation shape, test whether the similarity represents a reusable rule under the evidence rules above. Record replayable searches, examined hits and exclusions, then report:

exemplars: <file:line> per independent lineage; copies listed under their source
invariant: <what every exemplar shares and the behavior needs>
variation: <legitimate differences>; incidental: <syntax, names>
cost:      <demonstrated cost of violation, or "none found">
shape:     <no action | reference line | template | helper | gate> and why
outcome:   hypothesis | promote (three independent exemplars, passing holdout and back-application)

A selected durable pattern-mining.v1 record follows the pattern pack contract, checked by skills/research/scripts/pattern-mining/validate-output.sh. Research returns evidence; adoption remains an explicit caller decision.

Output and boundaries

Return a cited answer directly unless a durable output was requested or the selected evidence contract requires one. Ordinary durable reports follow findings.json: question, scope, answer, evidence, contradictions, unknowns, checked and unchecked areas. Multi-report synthesis also retains source_ledger and comparison. Selected recon and pattern modes retain their own validated formats instead of forcing them into this schema. To save a report, use the location the caller named, else the repository's existing research or decision-notes location and naming; with neither, return the answer and ask where to save it. Read the file back and report its exact path.

Use only authorized sources and destinations. For restricted or mined episode material, follow Memory's access and storage boundary. Research selects no work, owns no merged context store, mutates no lifecycle state and issues no semantic verdict. The native caller owns implementation, judgment and completion of the authorized outcome.