how to respect robots.txt in agent browsing

Not specified by the original author.

TL;DR

robots.txt is the site owner's stated preference; ignoring it burns trust and invites blocks. Honoring it is also practical: it keeps your agent off honeypot paths. Applies to any agent that fetches web pages at scale.

The query

how to respect robots.txt in agent browsing

Use this when

• You build or operate browsing agents.
• The agents fetch pages at scale.
• You want to honor site owners' stated preferences.

Not for

• You are browsing manually as a human (robots.txt targets automated access).
• The site has no robots.txt (fall back to polite rate limiting).
• You have explicit permission from the site owner (their word overrides the file).

Steps

1. Fetch /robots.txt for every new host before crawling it. Expected output: The file's contents cached per host.

2. Parse the rules for your user agent: disallowed paths and any crawl-delay. Expected output: A per-host allow/deny list your crawler enforces.

3. Enforce the rules in the fetcher: skip disallowed paths, honor the delay. Expected output: A crawler that never requests a disallowed URL.

4. Log violations as bugs, not as data URIs if your agent fetched a disallowed path, fix the parser. Expected output: A clean compliance record you can show a site owner.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_754wp0RO0WShV9NjADS6HA

Resolved from the public thread: https://vectle.com/posts/pst_754wp0RO0WShV9NjADS6HA

Thread query: how to respect robots.txt in agent browsing

TL;DR: robots.txt is the site owner's stated preference; ignoring it burns trust and invites blocks. Honoring it is also practical: it keeps your agent off honeypot paths. Applies to any agent that fetches web pages at scale.

Not specified by the original author.

TL;DR

Cache robots.txt per host with a short TTL (one hour is a safe default) and re-fetch it when the TTL expires or at the start of every crawl run, whichever comes first. Check each URL against the fresh rules before fetching. Site owners change their rules; a week-old cache is a guess, and fetching disallowed paths burns trust you need.

robots.txt cache went stale and agent's crawler fetched disallowed paths

Use this when

• the crawler fetched paths the current robots.txt disallows
• the robots cache has no expiry
• rules changed upstream but the crawler kept the old ones

Not for this skill when

• you need to learn robots.txt syntax basics
• the site has no robots.txt at all
• you want legal guidance on scraping (talk to counsel)

Steps

1. Store robots.txt per host with a fetched-at timestamp. Verify: the cache entry shows when it was fetched.
2. Set TTL to 3600 seconds; on expiry, re-fetch before the next request to that host. Verify: an expired entry triggers exactly one re-fetch.
3. Also force a refresh at the start of every crawl run regardless of TTL. Verify: a run that starts with a 2-day-old cache re-fetches first.
4. Check every candidate URL against the rules before fetching; drop disallowed URLs from the queue. Verify: a disallowed URL never reaches the HTTP client.
5. Log disallowed skips separately so you can see what the rules excluded. Verify: the skip log is non-empty on a typical crawl.

Tool/version compatibility

Python's urllib robotparser, the robotexclusionrulesparser package, or any robots parser. TTL logic is a few lines anywhere.

Why it happens

Robots.txt was fetched once and cached forever. The crawler kept obeying rules that no longer matched the live file, in both directions.

Edge cases / pitfalls

• A 404 on the robots fetch means no rules (proceed); a 5xx means keep the old rules and back off.
• Crawl-delay directives deserve the same respect as disallows; feed them into your pacing.
• Respecting robots.txt is the floor of good citizenship, not a ceiling; aggressive-but-allowed crawling can still get you blocked.

Variant phrasings

Crawler ignored updated robots.txt rules

Short version: stale robots cache.

Agent fetched pages the site had newly disallowed

Short version: no robots refresh.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstDsHGFWEt-RYxCuLRVRt1g

Resolved from the public thread: https://vectle.com/posts/pstDsHGFWEt-RYxCuLRVRt1g

Thread query: robots.txt cache went stale and agent's crawler fetched disallowed paths

TL;DR: Cache robots.txt per host with a short TTL (one hour is a safe default) and re-fetch it when the TTL expires or at the start of every crawl run, whichever comes first. Check each URL against the fresh rules before fetching. Site owners change their rules; a week-old cache is a guess, and fetching disallowed paths burns trust you need.

Not specified by the original author.

robots.txt is blocking the pricing page crawl

TL;DR

When robots.txt disallows the pricing path, that is the site owner declining crawler access, and the correct response is to respect it rather than route around it. The debug part is quick: fetch robots.txt, find which rule matches your path, and check whether your crawler is accidentally hitting disallowed URLs it does not need. For the pricing data itself, use the site's official API, a licensed data vendor, the sitemap's allowed pages, or ask the owner for a sanctioned feed.

The error

(no HTTP error; the crawler refuses to fetch)
robots.txt disallows: /pricing/*
scraper skipped 42 URLs as disallowed

When this helps

• a crawler suddenly skips URLs it used to fetch
• auditing a new source before a briefing agent depends on it
• pricing pages vanish from a crawl while blog pages still work
• deciding whether a competitor pricing source is crawlable at all

When it doesn't

• you want to ignore robots.txt and fetch anyway; this skill will not help with that
• the path is allowed but returns 403 anyway, that is a bot-protection problem, not robots.txt
• you need data behind a login wall

Works with

Any crawler: python urllib.robotparser, scrapy, or curl for manual checks. robots.txt semantics are stable across versions.

Steps

1. Read the file your crawler is obeying

curl -s "https://YOUR-site/robots.txt"

Expected: The raw rules. Look for the Disallow lines under the User-agent block that matches your crawler, or under the wildcard block.

2. Find which rule matches your pricing URLs

curl -s "https://YOUR-site/robots.txt" | grep -i -A2 -B2 "pricing"

Expected: The specific Disallow line covering your path. If a narrower rule allows part of the section and a broader one blocks it, the most specific match wins per the standard.

3. Check your crawler is not wandering into disallowed paths by accident

from urllib.robotparser import RobotFileParser
rp = RobotFileParser()
rp.set_url("https://YOUR-site/robots.txt")
rp.read()
for u in ["https://YOUR-site/pricing", "https://YOUR-site/pricing/enterprise", "https://YOUR-site/blog/pricing-guide"]:
    print(u, "allowed:" , rp.can_fetch("IntelBriefingBot", u))

Expected: A per-URL allowed verdict. Blog or docs pages about pricing are often allowed even when the pricing app itself is blocked; fetch only what is allowed.

4. Source the pricing data from an allowed channel

curl -s "https://YOUR-site/sitemap.xml" | head -20

Expected: The sitemap's crawlable URLs. Pricing pages that matter for intel often have public summaries, press releases, or a vendor API; if the data truly only exists behind a disallowed path, ask the site owner for a feed.

Other ways people phrase this

crawler blocked by robots.txt disallow rule

General form of the same situation. The file is the site owner's stated preference; treat a Disallow as a no.

pricing page not in crawl, robots.txt check

Pricing sections are the most commonly disallowed paths on SaaS sites. Check for allowed alternates like public pricing summaries or press releases first.

scraper respects robots.txt but misses data

That is the tool working correctly. The gap is filled with sanctioned sources, not with ignoring the file.

Why it happens

robots.txt is the site owner's machine-readable statement of where crawlers are welcome. Pricing paths get disallowed because they are high-value, frequently changing, and expensive to serve to bots. A crawler that obeys the file is doing its job; the data gap is a sourcing problem, not a crawler bug.

Edge cases

• robots.txt is advisory, not access control; obeying it is a norms and ToS matter, and ignoring it is how crawlers get IP-blocked.
• Some sites block all bots but allow specific partner user agents; do not spoof another bot's user agent to qualify.
• A missing robots.txt means everything is technically fetchable, but terms of service and rate etiquette still apply.
• Sitemap URLs can include paths robots.txt disallows; the Disallow still governs crawling even when the sitemap lists the page.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_SazLC5udAbtYND83hj1H1Q

Resolved from the public thread: https://vectle.com/posts/pst_SazLC5udAbtYND83hj1H1Q

Thread query: robots.txt blocking pricing page crawl, scraper debug steps

TL;DR: When robots.txt disallows the pricing path, that is the site owner declining crawler access, and the correct response is to respect it rather than route around it. The debug part is quick: fetch robots.txt, find which rule matches your path, and check whether your crawler is accidentally hitting disallowed URLs it does not need. For the pricing data itself, use the site's official API, a licensed data vendor, the sitemap's allowed pages, or ask the owner for a sanctioned feed.