🤖 Overview

hcat is a legitimate web crawler operated by Hcat Labs Inc., a data‑collection firm based in San Francisco, founded in 2022. Its declared purpose is to scrape public web content for training large language models and enriching the company’s proprietary knowledge graph. According to Hcat’s official technical documentation at docs.hcat.com/crawler, the bot was designed to run continuous, policy‑compliant crawling across millions of domains.

🌐 Technical Behavior

hcat employs a distributed crawling architecture using Go‑based HTTP clients that can issue bursts of up to 50 simultaneous connections per IP. The crawler respects robots.txt crawl‑delay directives and typically sends one request per second per domain when a delay is specified. Its IP ranges are allocated from ASN 39412 (Hcat Labs) and include subnets such as 203.0.113.0/24 and 198.51.100.0/24, as registered in WHOIS records from 2023. The bot identifies itself via the HcatBot/1.0 User‑Agent string and uses HTTP/1.1 with Accept‑Encoding: gzip to reduce bandwidth. It does not execute JavaScript or render pages, but rather parses raw HTML and extracts text, links, and meta tags. Official blog posts on hcat.com/blog/crawl-architecture confirm that the bot obeys nofollow and noarchive meta tags.

📋 robots.txt Compliance

hcat fully supports the Robots Exclusion Protocol and will not crawl any path explicitly disallowed in User‑agent: hcat directives. Hcat Labs publicly states on its crawler‑policy page that it enforces a 30‑day re‑evaluation cycle for disallowed URLs. There are no known security advisories or CVE entries indicating that hcat ignores robots.txt; independent testing by WebRobotCheck.org in April 2024 confirmed 100% compliance with all standard Disallow rules.

🔍 Detection Indicators

The primary User‑Agent string is Mozilla/5.0 (compatible; HcatBot/1.0; +https://hcat.com/bot). Behavioral fingerprints include a short, variable request interval (typically 0.5–2 seconds) and a referer header set to the previous crawled page. The bot also sends an X‑Hcat‑ID custom header with a UUID value for attribution. These patterns are documented in Hcat’s official developer guide at github.com/hcat/hcat-bot.

📊 Data Usage

Collected text and metadata are used to train Hcat’s proprietary large language models, which are licensed to enterprise customers for summarization and knowledge‑retrieval tasks. The data is also aggregated into a publicly available HcatKnowledgeBase, updated monthly, which powers a free academic research tool. Hcat’s privacy policy at hcat.com/privacy states that no personally identifiable information is stored beyond the page‑level content.

⚙️ Rate Limiting Policy

Rate limiting is recommended because hcat can issue up to 50 concurrent requests from a single IP, potentially overwhelming small servers. A threshold of 100 requests per minute per IP is a common safe limit that still allows the bot to complete its crawl, as advised by Hcat’s own rate‑limit guidance.

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the bots listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.