RuleDost

Oct 26, 5:00pm EDT is 2:30 AM Tuesday in Jaipur. Paste a hackathon's rules and RuleDost shows your real deadline, whether you can enter and what to submit, each with its source sentence.

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Try it: https://ruledost.vercel.app · Demo video (2:36): https://youtu.be/p5daJsw4q28 · Code (MIT): https://github.com/Thanatos9404/ruledost

Inspiration

This hackathon's rules page says "Deadline: Oct 26, 2026 @ 5:00pm EDT". In Jaipur, where I study, that is 2:30 AM on Tuesday, 27 October. The real cutoff is the middle of Monday night.

My list for October 2026 had 13 hackathons. Their deadlines used seven time-zone labels: EDT, EST, PDT, PST, MSK, UTC and IST. Eligibility changes too: one event excludes Italy and China, another is open only to members of a company program. I was converting times in my head and sometimes finding a requirement late.

What it does

RuleDost ("dost" means friend in Hindi) reads a pasted rules page and answers three questions:

  • When is it really due? The deadline in your time zone (from your browser, so IST in India), a live countdown, and a warning when the date shifts or the deadline lands between midnight and 6 AM.
  • Can I enter? Age, country and membership rules, checked against your details: Looks eligible, Check these or Not eligible.
  • What must I submit? A tickable checklist: video, repo, licence, new-code rule, required files and more. The prize is shown in USD and rupees.

Every row has a Receipt toggle that quotes the sentence it came from, with the deciding phrase highlighted. A tracker only stores dates you type in, and a chatbot summary is hard to check. RuleDost shows its source, so you can check it instead of trusting it.

My hackathons sorts saved events by your real deadline, and an .ics export adds reminders 1 day and 3 hours before. It runs in your browser: no server, no account, no AI call at runtime.

Try ruledost.vercel.app/#sample=northern, a fictional US-and-Canada-only challenge. It comes back Not eligible for India, with the sentence that says why.

Limits: it is tuned for Devpost-style pages, and other formats get more Check rows. It reads "age of majority" as 18, which is right for India. It shows evidence, not legal advice.

Who it is for

Indian college students who enter several online hackathons at once, most of them run from the US. The first user is me.

How I built it

I started from an empty folder with the Devpost Learn skill pack and built RuleDost with Claude Code, an AI coding agent, from a written brief. It followed the skills in order (scope, PRD, spec, build) and wrote the docs and the code. The spec named one key unknown: can pattern matching handle real rules pages, or is this a toy? The devpost/ folder records which decisions I delegated and where the build changed the plan.

The build went in five tested slices. Later I had the front end rebuilt in React, Vite, TypeScript and Tailwind CSS on my shared design kit, disclosed in the README. The decoder is dependency-free JavaScript on the built-in Intl time-zone data, with 54 unit tests.

No LLM at runtime was a choice. A pattern either matches a sentence or it does not, so every answer has a receipt. It is free, needs no network once loaded, and can misread a sentence but not make one up. The cost is lower coverage outside the Devpost template.

Challenges I ran into

  • Devpost's exclusion sentence mentions "the U.S. Treasury", so a naive match marked US students as excluded. Such phrases are now ignored.
  • "Pacific Time" is PDT in October and PST in December, so generic wording follows real daylight-saving rules.

Accomplishments that I am proud of

I answered the spec's question with numbers. The decoder ran on 39 saved copies of real Devpost pages (three tabs each from 13 hackathons, Rules pages included). It found a deadline in all 39, and all 13 Rules-page deadlines were correct when checked by hand.

Smaller things: the verdict badges pass WCAG AA contrast, and the app works at 375 px.

What I learned

  • Write the main promise as a test first. The first test was the EDT-to-IST deadline above.
  • Real pages find bugs that clean test text misses, like the Treasury one.
  • With an AI agent, a clear brief and written-down decisions are what let me check its work.

What is next

  • Paste a URL instead of text, through a small proxy.
  • Hindi explanations of checklist items.
  • An optional LLM fallback for unusual formats that must still quote its sentences.

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