* fix(robots-check): stop a leading BOM or an undecodable rule from reading as allowed
Two decoding edge cases left the robots gate failing open. Both were
flagged as follow-ups in #506.
A robots.txt saved with a UTF-8 byte-order mark decodes to a body that
starts with U+FEFF, so its first field read as U+FEFF + "user-agent". A
leading "User-agent: *" went unseen, every rule in that group was
dropped for want of an agent, and "Disallow: /" read as allow-all.
_groups() and is_robots_body() now skip one leading U+FEFF, as Google's
reference parser does, which covers every caller of allowed(). This
predates #506: the old code-page decode hid the line the same way.
Since #506 pinned curl's output to UTF-8 with errors='replace', a
non-conformant robots.txt saved in a legacy code page (cp1254,
ISO-8859-9) with raw non-ASCII bytes in a rule decodes them to U+FFFD.
That rule can never match and was silently skipped. The new
has_undecodable_rule() treats such a body as unreadable, so the gate
returns UNCONFIRMED (exit 1). The field is named with U+FFFD removed, so
a stray byte before "Disallow" cannot hide the line either. U+FFFD in a
comment or another field (Sitemap, Crawl-delay) stays harmless, and
valid UTF-8 non-ASCII rules decide as before.
Nine new tests in two FAIL-OPEN REGRESSION classes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* docs(changelog): record the robots_check BOM and U+FFFD fixes
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---------
Co-authored-by: Can Mugan <217335573+canmugan@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
_fetch() ran curl with text=True and no encoding, so Python decoded the
response with the Windows ANSI code page. On a byte that code page leaves
undefined (0x81 in cp1252 and cp1254, 0x9e in cp1254) subprocess's pipe
reader thread died, stdout came back None, rpartition() raised
AttributeError, and the gate printed "UNCONFIRMED (AttributeError)". That
fails closed, but it blocked the browser-header retry 09-web-research.md
permits on hosts such as tr.indeed.com (a UTF-8 CJK Disallow rule) and
kap.org.tr (a UTF-8 Turkish 404 page).
Pin encoding='utf-8', errors='replace' on the call (RFC 9309: robots.txt
is UTF-8), as verify_pdf.py and verify_layout.py already do. Decision
rules and the fail-closed handling of real read failures are unchanged.
The regression tests swap curl for a child process that prints the real
bytes, so the actual subprocess decode path runs with _fetch's own
kwargs, and pin cp1254 when no encoding is passed so a UTF-8 host cannot
pass the bug by luck. Both fail on master.
Co-authored-by: Can Mugan <217335573+canmugan@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
The tie-break test listed Disallow first - the one ordering where
deleting the clause changes nothing - and gate()'s read-the-policy-as-a-
browser recovery (the Barclays-class case 09-web-research.md documents
as covered) had no test. Both gaps are guard code whose breakage is
silent by construction. Mutation-verified: the tie-break deletion and
the UA-loop reduction each now fail exactly the new tests. Review
findings F21 and F30 (2026-08-19).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Found by an adversarial review run over the merged checker, prompted to falsify
rather than confirm. Both are pinned in tests/test_robots_check.py.
A soft 200 granted permission. A host answering /robots.txt with an HTML error
page at status 200 produces a body that parses to zero rules, and zero rules
read as "allowed" - so the browser-header retry ran on permission that was
never given:
rc._fetch = lambda url, ua: ("<html>404 Not Found</html>", 200)
rc.gate("https://x.example/jobs")
# -> (0, 'ALLOWED - robots.txt permits this path')
A non-empty body carrying no recognised directive is now treated as unreadable.
A genuinely empty file stays allow-all per RFC 9309, so this does not
over-correct.
Disallow patterns were never percent-decoded while the request path was, so
"Disallow: /foo%20bar" never matched "/foo bar" and the rule was silently
skipped.
Also adds the "--" terminator before the URL in the curl argv, plus an explicit
--max-redirs 5. gate() rebuilds the target as scheme://host/robots.txt before
calling _fetch, so the gate path was never exposed to a dash-leading URL - this
is hardening for direct callers. Three tests pin it: the terminator is present,
a dash-leading argument fails closed end to end, and gate() never passes a
caller-supplied URL through to curl.
187 tests pass.
Claude-Session: https://claude.ai/code/session_01XTtiXab1yUFF2aL4s3fVY1
Co-authored-by: kgb <kevingblackman@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
* fix(web-research): stop treating a WebFetch 403 as a dead posting
WebFetch sends a bot user agent, and many bank and corporate sites answer
with HTTP 403 while serving the same page to a browser normally. Every
command treated that as "page unavailable" and degraded silently rather
than failing loudly:
- /rank marked live postings `expired`
- /apply fell back to search snippets, or to vague cover-letter prose
- /scrape stored listing-page `#fragment` URLs, which fetch fine and
return unrelated jobs, so every later /rank and /apply run on that
entry failed
Adds 09-web-research.md as the single reference: the trust boundary, a
curl browser-header retry with a tag-stripping extractor, a four-step
escalation order, the login-wall case, why the employer's own careers
posting beats an aggregator listing (the requisition ID and the grade
survive there), and the rule that a search-result snippet is a lead
rather than a source.
Wires it into /apply, /rank, /interview, /outcome, /notion-sync, the
job-scraper skill, and writing-style rule 5. Bumps 03-writing-style.md
to 1.2.0; 09-web-research.md starts at 1.0.0.
Aggregator examples are given generically (LinkedIn, Indeed, national
job boards) so the guidance holds in any market.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
* fix(web-research): gate the browser-header retry on robots.txt
Addresses review feedback on #277.
WebFetch identifies itself as Claude-User and honors robots.txt, so a 403 has
two very different causes and they must not be treated the same: a WAF default
on a site whose published policy allows access, or a site that has actually
declined. Retrying with browser headers in the second case circumvents the very
opt-out mechanism site owners are told they can rely on, and the core framework
cannot hold a looser standard than it asks of community forks.
The escalation now runs tools/robots_check.py before the retry. A disallow for
"*" or for "Claude-User" skips the retry entirely and goes to step 3 (find the
employer's own posting). The rule is stated plainly in 09-web-research.md so
later edits do not erode it: the retry exists to get past bot-filtering
firewalls on sites whose robots.txt permits access; it is never used to
override a site that has said no.
Two findings from testing the gate against live sites, both pinned by
tests/test_robots_check.py (15 offline cases):
- The WAF usually blocks robots.txt too. privatebank.barclays.com returns 403
on the policy file to Claude-User and 200 to a browser, so a naive gate would
block the retry on exactly the sites the retry is for. The checker reads the
policy as a browser when the honest request is refused, then obeys it
strictly - a policy you are prevented from reading cannot be honored, and
robots.txt is not the protected resource.
- urllib.robotparser cannot be used. It ends a record at a blank line and
matches rules in file order, so Barclays' real file (blank lines between
"User-agent: *" and its rules, "Allow: /" before "Disallow: /cs/") reads as
everything-allowed. That fails open, in the one direction that matters. The
checker implements RFC 9309 longest-match instead, with ties resolved to
Disallow rather than Allow.
Verified live: barclays /careers/ allowed and /cs/ blocked, ubs.com allowed,
jobup.ch /api/ blocked while /en/jobs/ stays allowed. 09-web-research.md
1.0.0 to 1.1.0.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
---------
Co-authored-by: kgb <kevingblackman@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
Oscar Madera