---
name: sources
description: 'Consult the project''s trusted-sources registry before searching the web or adding a dependency/tool, and ground every shown fact in a verified origin. Use when the user asks to search/research/look something up, find docs or an API signature, choose or add a dependency/library/tool, or mentions "/sources". Reads docs/SOURCES.md, prefers its Tier-1 trusted sources, version-pins to the project stack, vets any new dependency with the both-ends advisory check, records the decision, and flags anything un-corroborated as a conjecture. Never invents a citation, version, or stat; never adds an unvetted/typosquatted package.'
license: MIT
allowed-tools: WebSearch, WebFetch, Read, Edit, Bash
---

# Sources — trusted-first search & dependency vetting

## Overview

A shown fact without a verified origin does not exist; an uncorroborated claim is a conjecture, not a fact.
This skill applies that at the moment of *searching* and of *choosing dependencies*.

The registry is the project's `docs/SOURCES.md`; **read it fresh** each run — it is the source of truth for what to trust:

```bash
cat docs/SOURCES.md
sed -n '1,40p' CLAUDE.md                                    # the stack and versions to pin to
```

**Invocation is the authorization** for the search/vetting itself. The only thing surfaced to the operator is
a genuine fork (a license conflict, a risky-but-wanted dependency, a missing trusted source for a critical
fact) — and **the operator approves the actual install or commit**, as for any change.

## A — When asked to search / research / look something up

1. **Trusted-first.** Identify the domain and go to its **Tier-1** source in `SOURCES.md` §3 before the open
   web (official language/framework docs, the standard, the package's own repo, this repo's own docs).
2. **Version-pin.** Match the project's installed major version (lockfile plus `CLAUDE.md`) — docs for the
   wrong version are a silent trap.
3. **Corroborate & cite.** Any Tier-2/3 finding is confirmed against a Tier-1 source before you rely on it;
   cite the origin inline. **Ground every fact** — `origin(fact) = None ⇒ drop it`, never paraphrase a guess
   into a claim.
4. **Conjecture-flag the rest.** Anything from an unlisted or Tier-3 source is presented as a conjecture with
   its falsifier, or withheld — never asserted as fact.
5. **Compound the registry.** If you found a genuinely trustworthy source not in §3, **add it** (tier + one
   line on why) so the registry grows. For Claude/Anthropic model facts, defer to the **`claude-api`** skill.

## B — When asked to add a dependency or tool

Run the `SOURCES.md` §4 **vetting checklist** — do not skip a box:

```bash
# real & canonical (not a typosquat): inspect the package's OWN registry page + linked repo
#   e.g.  npm view <pkg> repository.url   /   pip show <pkg>   /   cargo info <pkg>   — then open the real repo
# advisory-clean, BOTH ENDS (the current version if replacing, and the target you'd add) — cmd from SOURCES.md §5:
#   npm audit  /  pip-audit  /  cargo audit  /  govulncheck   + query OSV / GitHub Advisory for exact name+version
```

- [ ] **Real & canonical** — exact name, official repo; **not** a look-alike/typosquat.
- [ ] **Maintained** — recent releases/commits, more than a lone anonymous maintainer.
- [ ] **Mature, not bleeding-edge** — a baked version (MAINTENANCE policy), never a week-old `.0`.
- [ ] **Advisory-clean (both ends)** — no known advisory, not yanked/deprecated.
- [ ] **License-compatible** with the project's license.
- [ ] **Earns its weight** — prefer the standard library or an already-present dep when it suffices.

Then: **record** it — add the row to `SOURCES.md` §4 (Approved) with the verified registry URL + today's
date (`date +%F`, never guessed), log the choice and its reason in `docs/DECISIONS.md`, and (if rejected)
add it to the §4 Rejected list so it isn't re-litigated. Propose the install command; the operator approves
the commit. A new dependency lands behind a **green `test-gate`**.

## Hard rules (stop if you catch yourself doing these)

- Citing a fact, version, statistic or API signature you did not verify against a real source. → ground it or drop it.
- Inventing a URL, citation, or release date. → the one unrecoverable error. Say "not found" instead.
- Adding a package because a search surfaced it, without the §4 checklist. → vet first; typosquats are real.
- Trusting a Tier-3 blog or Q&A as the origin of a fact. → corroborate against Tier-1, or mark it a conjecture.
- Pulling docs for the wrong major version. → pin to the project's lockfile.
- Running the actual install or commit without the operator's go, or before `test-gate` is green. → propose it.