Ten sources from Claude. One was retracted.

#!/usr/bin/env python3
"""Independent citation check used for the reel test (not the skill's own code).
For every numbered reference line in a text file: pull the DOI, ask Crossref (does it exist, what title,
any retraction notice) and OpenAlex (is_retracted), and compare the title with the one Claude wrote."""
import json, re, sys, time, urllib.parse, urllib.request, difflib
UA = {'User-Agent': 'promptanddone-citation-test/1.0 (mailto:[email protected])'}
def get(url):
    for i in range(3):
        try:
            return json.load(urllib.request.urlopen(urllib.request.Request(url, headers=UA), timeout=25))
        except urllib.error.HTTPError as e:
            if e.code == 404: return None
            time.sleep(2)
        except Exception:
            time.sleep(2)
    return 'ERR'
def norm(s): return re.sub(r'[^a-z0-9 ]', '', s.lower())
def main(path):
    out = []
    for line in open(path):
        m = re.match(r'\s*(\d+)\.\s+(.*)', line)
        if not m: continue
        n, body = m.groups()
        d = re.search(r'10\.\d{4,9}/[^\s<>"]+', body)
        doi = d.group(0).rstrip('.,;)') if d else None
        t = re.search(r'\(\d{4}[a-z]?\)\.\s+(.+?)\.\s+[\*_A-Z]', body)
        said = t.group(1) if t else body[:80]
        row = dict(n=int(n), doi=doi, said=said, status='NO DOI')
        if doi:
            cr = get('https://api.crossref.org/works/' + urllib.parse.quote(doi))
            if cr is None: row['status'] = 'FAKE (DOI does not exist)'
            elif cr == 'ERR': row['status'] = 'UNKNOWN (network)'
            else:
                msg = cr['message']; real = (msg.get('title') or [''])[0]
                row['real_title'] = real
                row['sim'] = round(difflib.SequenceMatcher(None, norm(said), norm(real)).ratio(), 2)
                row['status'] = 'REAL' if row['sim'] > .6 else 'MISMATCH (DOI is a different paper)'
                row['crossref_retraction_flag'] = real.upper().startswith('RETRACTED') or any(u.get('type') == 'retraction' for u in msg.get('update-to', []) or []) or bool(msg.get('relation', {}).get('is-retracted-by'))
                oa = get('https://api.openalex.org/works/doi:' + urllib.parse.quote(doi))
                row['openalex_is_retracted'] = (oa or {}).get('is_retracted') if isinstance(oa, dict) else None
                if row['crossref_retraction_flag'] or row['openalex_is_retracted']:
                    row['status'] = 'RETRACTED' if row['status'] == 'REAL' else row['status'] + ' + RETRACTED'
        out.append(row)
    print(json.dumps(out, indent=1, ensure_ascii=False))
    from collections import Counter
    print(Counter(r['status'] for r in out), file=sys.stderr)
main(sys.argv[1])