A plain-text file at app.onepassapps.com/llms.txt tells language models what this site is. I found it while probing the site for the surfaces a machine can read, and it is the first one I have written about: a file aimed at AI tools rather than browsers, served as text/plain, and - I will come back to this - not linked from our own pages.

I work on OnePassApps, the team behind app.onepassapps.com, so everything below is a measurement of our own live site on 4 November 2026, fetched over plain HTTPS with no JavaScript and no signed-in session.

What the request actually returns

The file answers HTTP 200 with the content type text/plain; charset=utf-8 and 6065 bytes across 62 lines. The response headers worth naming: cache-control: public, max-age=0, must-revalidate, etag: "8d5d467560c1c75e964f129b140f2274", no Last-Modified. It is a static file at the root of the host, one request, no redirect.

What the file says

The header is the plain sentence one would expect: Organise PDFs, build a résumé, chart CSV data and create designs in your browser. Use local tools without an account and explore OnePassApps membership.

Underneath it the file is organised into 7 sections - Live apps, Access and cost, App guides, Browser-local Studios, Platform information, Plans and prices, Terms of use sections - and 15 linked entries, each one a name, a URL and a short description:

  • NewsFlow - Read attributed stories, open original sources, listen to briefs and manage a session queue with NewsFlow.
  • MovieMatcherAI - Browse movies and TV series, keep Unwatched and Watched lists, and record private ratings, reviews and reactions after signing in.
  • All app guides - Supported tasks, steps, formats, and limitations.
  • How to read briefs and listen with NewsFlow - Use NewsFlow to read attributed stories, open original sources, listen to briefs, and manage a session listening queue.
  • How to track movies and TV in a private watchlist - Browse movies and TV series, keep Unwatched and Watched lists, and use private ratings and reactions in MovieMatcherAI.
  • Image Studio - Convert, compress, resize, crop and prepare images on this device. Tools: Convert, Compress, Resize, Crop, Remove background, Remove metadata, Images to PDF.
  • Audio Studio - Trim and convert local audio with formats checked against your browser. Tools: Convert, Compress, Trim, Extract.
  • File Studio - Create archives, compare hashes, rename copies and join split files. Tools: ZIP files, Unzip files, Batch rename, File hash, Find duplicates, Split file, Join parts.
  • Text Studio - Clean, compare, convert and inspect text in your browser. Tools: Clean, Case, Duplicate lines, Sort lines, Find & replace, Diff, Markdown, Base64.
  • Data Studio - View and transform CSV, JSON and YAML without sending data anywhere. Tools: CSV viewer, Sort / filter, Columns, Remove duplicates, Merge CSV, Split CSV, CSV to JSON, JSON formatter, JSON validator, JSON to CSV, JSON and YAML.
  • Icon Studio - Make favicon and app-icon files, resize images and work safely with SVG. Tools: SVG to PNG, PNG to ICO, Favicon pack, App icons, Resize set, Optimize SVG, Recolour SVG, Trim / padding.
  • Colour Studio - Sample colours, build palettes and check accessible contrast locally. Tools: Picker & converter, Contrast & gradient, Palettes, Image sampler.
  • Plans and pricing - OnePassApps free promotional period: Standard included for every account, with 100,000 credits every 30 days. No card or automatic paid subscription.
  • Terms of use - Read the OnePassApps terms of use, privacy notice, payment, cancellation and refund policy, and usage rules.
  • Vote on future apps - Review product ideas and help shape which practical apps OnePassApps builds next.

That is the whole idea of the format: a markdown outline of the site, written for a model to read before it decides whether to fetch anything else. No script, no JSON, no schema.

Every URL it lists, checked

I fetched each of the 15 URLs the file points at, one request each, and every one of them answers HTTP 200:

path status | /apps/movie-tracker | 200 | | /apps/newsflow | 200 | | /guides | 200 | | /guides/movie-tracker | 200 | | /guides/newsflow | 200 | | /plans | 200 | | /studios/audio | 200 | | /studios/colour | 200 | | /studios/data | 200 | | /studios/files | 200 | | /studios/icons | 200 | | /studios/image | 200 | | /studios/text | 200 | | /terms | 200 | | /voting | 200 |

A guide that points at a URL that does not answer is worse than no guide, so this is the part worth checking on any site that publishes one.

Nobody links to it

The llms.txt convention says the file should be reachable from the homepage, and ours is reachable - app.onepassapps.com/llms.txt answers 200 for anyone who asks for it. But on our own site, three places that could point at it do not:

  • sitemap.xml lists 16 URLs and llms.txt is not one of them
  • robots.txt does not mention llms.txt
  • the homepage HTML does not carry a link to it

That is a fact about discoverability rather than a bug: a crawler that reads robots.txt or the sitemap will not stumble across this file. The people who read it are the ones already told to look.

What this file is not

Some honest limits, because the format is young and easy to oversell:

  • It is advisory text. Nothing in the build enforces it, nothing reads it at runtime, and it is not a ranking factor for any search engine I can measure.
  • It does not replace the machine-readable surfaces the site already has - the XML sitemap, robots.txt, the JSON-LD graph on each page, the web app manifest. Those describe the site's structure; llms.txt describes the site's intent in prose.
  • The file describes nine apps and a membership. It does not claim numbers, reviews or features I did not check.
  • This is one build on one day, fetched from one network with Cloudflare in front of the origin. A different point of presence could answer differently.

The short version

The site serves a plain-text map of itself for AI tools at app.onepassapps.com/llms.txt. It is 6065 bytes, 7 sections, 15 entries, and every URL it lists answers 200 today. It is not in our sitemap, not in robots.txt, and not linked from the homepage - so if you want it found, ask for it by name.

If you want the same treatment for the tools themselves, the written walkthroughs are on the OnePassApps guides page, and the apps themselves are at app.onepassapps.com.

I work on OnePassApps - the studios process the file in the tab, not on a server.