Cursor rule

1---
2description: "Look-before-build — search registries, repo, existing skills, and web for prior art before implementing. Appends Prior Art to the spec. Use after survey-context and before elaborate-spec, when adding dependencies, or when the task may already be solved."
3alwaysApply: false
4---
5 
6# story: e03s01
7# story: e21s02
8 
9# Research First
10 
11> **HARD GATE** — Do NOT implement until prior art is searched. Minimum outcome: adopt, extend, compose, or build — with evidence.
12 
13## Process
14 
151. Read `specs/product/SCOPE_LATEST.yaml`, `specs/release-plan.yaml + epic shards`, and the current task statement.
162. Search in order: this repo → bigpowers skills (`search-skills`) → package registries → web docs.
173. **Check opensrc cache** — if the task integrates an external library, run `bash scripts/bp-opensrc-check.sh` (or `npx opensrc search <pkg>`) to find locally-cached source. Read the `src/` directory for API shapes before writing any integration code.
184. For each candidate: note name, URL/path, fit (adopt | extend | compose | build).
195. Append `## Prior Art` to `requirements/SCOPE_LATEST.yaml` notes or the active epic story.
20 
21## opensrc Integration
22 
23`opensrc` is a local cache of 200+ open-source repos and npm/PyPI packages. Query it before building any external integration to avoid re-inventing documented API shapes.
24 
25```bash
26# Check if a package is cached
27npx opensrc search &lt;package-name&gt;
28 
29# Or use the bundled helper (checks all deps from package.json or requirements.txt)
30bash scripts/bp-opensrc-check.sh [package.json|requirements.txt]
31```
32 
33If opensrc finds a match, read its `src/` or source directory and append findings to the **Prior Art** section:
34 
35```
36opensrc: found <pkg> v<version> — exports <key classes/functions>
37```
38 
39If opensrc is not installed or the package is not cached, fall through to web docs normally.
40 
41## Outcome matrix
42 
43| Verdict | Action |
44|---------|--------|
45| **adopt** | Use as-is; link in plan; no new code |
46| **extend** | Wrap or configure existing solution |
47| **compose** | Chain existing skills/modules |
48| **build** | New implementation — justify why others failed |
49 
50## Verify
51 
52→ verify: `grep -rq 'Prior Art' specs/product specs/release-plan.yaml specs/epics 2>/dev/null`
53 
54See [REFERENCE.md](REFERENCE.md) for search commands and registry checklist.
55 
56---
57 
58# Research First — Reference
59 
60## Search commands
61 
62```bash
63# Repo prior art
64rg -l &quot;&lt;keyword&gt;&quot; --glob '!node_modules' .
65find . -maxdepth 3 -name &quot;SKILL.md&quot; | xargs grep -l &quot;&lt;intent&gt;&quot;
66 
67# Installed packages (if package.json exists)
68cat package.json | jq '.dependencies,.devDependencies' 2&gt;/dev/null
69```
70 
71## Registry checklist
72 
73- [ ] npm / PyPI / crates.io (if applicable)
74- [ ] Existing bigpowers skill (`bash scripts/build-skill-index.sh && rg "<intent>" specs/SKILL-SEARCH-INDEX_LATEST.md`)
75- [ ] Project `docs/` and `specs/adr/`
76- [ ] Official library documentation (quote one API detail)
77 
78## Prior Art template
79 
80```markdown
81## Prior Art
82 
83| Candidate | Source | Verdict | Notes |
84|-----------|--------|---------|-------|
85| ... | ... | adopt/extend/compose/build | ... |
86```
87