infra-check

infra-check is a single-file command-line tool that inspects any domain for machine-readable infrastructure signals — the kind of things that determine how well a site can be understood by crawlers, AI agents, and automated clients. It runs five checks per domain and produces a binary PASS / FAIL verdict, with optional CSV or JSON export for batch runs.

What it checks

#	Check	What it looks for
1	JSON-LD	Presence of valid application/ld+json structured data on the homepage, and the @types it declares.
2	llms.txt	Whether the domain serves a non-trivial /llms.txt file at the root.
3	robots.txt	Whether /robots.txt exists, whether generic bots are allowed, and which known AI crawlers (GPTBot, ClaudeBot, Google-Extended, CCBot, …) are blocked.
4	Headers	HTTP status, a valid text/html content type, and the presence of common security headers (HSTS, X-Content-Type-Options, X-Frame-Options, CSP).
5	SSL/TLS	That the domain responds over HTTPS without certificate errors.

A domain passes when at least 3 of the 5 checks pass.

Installation

infra-check needs Python 3 and a single dependency:

pip install requests

Then grab the script and run it directly — no packaging or install step required:

python infra-check.py --help

Usage

Single domain

python infra-check.py example.com

Multiple domains

python infra-check.py example.com another.com third.org

Batch from a file

Provide a text file with one domain per line (blank lines and # comments are ignored):

python infra-check.py --file domains.txt

Export to CSV

python infra-check.py --file domains.txt --csv results.csv

Export to JSON

python infra-check.py --file domains.txt --json-out results.json

Quiet mode (verdict lines only)

python infra-check.py --file domains.txt --quiet

All options

Option	Description
domains	One or more domains to check (e.g. example.com).
--file, -f	Path to a text file with one domain per line.
--csv	Write full results to a CSV file.
--json-out	Write full results to a JSON file.
--quiet, -q	Only print the verdict lines.

Sample output

Checking 2 domain(s)...

✅  example.com  [PASS]  (4/5 checks passed)
   JSON-LD:     valid (Organization, WebSite)
   llms.txt:    missing
   robots.txt:  open
   Headers:     HTTP 200, security headers: yes
   SSL/TLS:     valid

❌  broken.example  [FAIL]  (1/5 checks passed)
   JSON-LD:     missing
   llms.txt:    missing
   robots.txt:  missing
   Headers:     unreachable
   SSL/TLS:     SSL error: certificate verify failed

==================================================
Total: 2 | Passed: 1 | Failed: 1

License

Released under the MIT License.

Author

Thorsten Litzki — Litzki Systems LLC