guestlist
know which sites will let your agent in
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What is guestlist?
guestlist is an API tool that tells you, for any URL, whether AI agents are likely to get through. It continuously probes the web from real browsers and grades every domain on a color-coded scale from green to red based on how often crawls succeed. This allows developers to check before they crawl, skipping dead ends and saving API budget on requests that will fail.
The tool provides a simple Python client (pip install guestlist-tools) that reads the GUESTLIST_API_KEY from environment variables. You can check multiple URLs in a single API call and get back tier ratings along with blocker detection information. The API returns whether the domain is green (almost always), yellow (usually), orange (sometimes), red (rarely), or unknown (untested).
This tool is designed for AI agent developers, web scrapers, and anyone running automated crawlers who wants to avoid wasting requests on sites that block agents. It's particularly useful before spending valuable API requests on crawling, allowing you to filter out problematic domains upfront.
Key use cases include preprocessing search results before crawling, optimizing web scraping pipelines, and building more efficient AI agents that can navigate the web without hitting constant blocks.
guestlist pricing
Pricing model: Freemium
The website shows 'get an api key' button but does not display specific pricing tiers, free tier details, or paid plan costs on the homepage. Pricing information is not publicly visible without signing up for an API key.
guestlist pros
- Saves API budget by avoiding dead-end URLs
- Single API call checks multiple URLs at once
- Continuous probing from real browsers for accurate data
- Color-coded tier system (green/yellow/orange/red/unknown) is intuitive
- Simple Python client with pip install guestlist-tools
- Reads API key from environment variable automatically
- Returns blocker_detected field to identify what's blocking
- Check before crawling prevents wasted requests
- Works for any URL on the web
- Grades every domain continuously, not just one-off checks
- Green tier means almost always accessible - use confidently
- Yellow tier usually works with occasional retries needed
- Orange tier suggests stealth/proxy fallback if available
- Red tier clearly signals to skip the domain
- Unknown tier for untested domains with caution guidance
guestlist cons
- Requires API key registration to use
- Unknown tier means untested - use with caution
- Orange and red tiers still require fallback solutions you may not have
- No guarantee of 100% accuracy since sites change blocking policies
- Only provides tier rating, not detailed blocking mechanism info
- May not work for dynamically generated or JavaScript-heavy blocks
- Rate limits not specified on the homepage
- Primary Python client shown, other language support unclear
Frequently asked questions about guestlist
What is guestlist.tools?
guestlist is an API tool that tells you, for any URL, whether AI agents are likely to get through. It continuously probes the web from real browsers and grades every domain green to red based on how often crawls succeed.
How does the tier system work?
The tiers are: green (almost always - use confidently), yellow (usually - use; expect occasional retries), orange (sometimes - use a stealth/proxy fallback if you have one), red (rarely - skip; try the next result), and unknown (untested - use with caution; report back what you saw).
How do I install the Python client?
Run 'pip install guestlist-tools' to install the Python client. The client reads the GUESTLIST_API_KEY from your environment variables automatically.
Do I need an API key?
Yes, you need to get an API key. The website has a 'get an api key' button for registration. The Python client reads GUESTLIST_API_KEY from the environment.
Can I check multiple URLs at once?
Yes, the client.check() method accepts a list of URLs and returns results for all of them in a single API call, as shown in the code example with Hacker News, NY Times, and Reddit.
What does blocker_detected mean?
The blocker_detected field in the response indicates what type of blocking mechanism was detected on that domain. It helps you understand why a site might be rated orange or red.
How often is the data updated?
The website states they 'continuously probe the web from real browsers' suggesting the data is updated on an ongoing basis rather than being static or one-time checks.
What should I do with orange-tier domains?
For orange-tier (sometimes) domains, the recommendation is to use a stealth/proxy fallback if you have one, since these sites only sometimes allow AI agent access.
Should I crawl red-tier domains?
No, for red-tier (rarely) domains you should skip them and try the next result, as crawls rarely succeed on these sites.
Who is this tool for?
This tool is for AI agent developers, web scrapers, and anyone running automated crawlers who wants to skip dead ends and save API budget before spending requests on URLs that will fail.