Guided build · an evening

Exam countdown & study plan

Breaks a big exam into a day-by-day plan that fits your time.

You will build this by describing what you want in plain words, in your own language. Claude writes the code; your job is to describe the result well and check it. Here is the whole path, start to finish.

ℹWhat you'll have at the end

Breaks a big exam into a day-by-day plan that fits your time.

First, how to actually talk to the agent

  1. 1Describe the RESULT, not the tech: what's on screen, what each button does, what gets saved. The agent handles the 'how'.
  2. 2Be concrete about screens and fields — 'a form with amount, category and date' beats 'let me add expenses'.
  3. 3Ask for the smallest working version first. You grow it by talking afterwards — that's Step 2, not the first message.
  4. 4Decide what's YOURS, not the agent's: name the categories, colours, rules. Don't make it guess what only you know.

Step 1 — Build it live

Prompting for this kind of tool

  1. 1For an exam planner, nail THREE things: the SETUP inputs (exam date plus a pasted list of topics), what the HOME screen shows (a big 'days left' number, a progress bar, then a day-by-day plan), and the killer RULE — when you tick a topic done, the unfinished ones automatically rebalance over the days still left.
  2. 2Decide the busy-day behaviour yourself: you can mark some days as busy and it schedules nothing on them, packing the rest tighter. Say this plainly or you'll get a rigid plan that ignores real life.
  3. 3Make the rebalancing automatic and explicit: 'I never re-plan by hand — ticking a topic or marking a day busy reshuffles everything left on its own.' That's the whole point of the tool.
  4. 4End with: 'build the whole thing, check that it works, and tell me exactly how to open it.'
Start Claude
claude

Open the terminal and run this (if Claude is already running, type /exit first). Then ask it to make a folder for this project and work inside it.

The wrong ask vs. the right ask
✕ what most people type
you ▸ pass the exam for me
✓ what actually works — copy it, or better, say it in YOUR words
you ▸ Build me an exam countdown planner. A setup screen where I enter the exam date and paste my list of topics. The home screen shows a big 'days left' number and a progress bar, then a day-by-day plan that spreads the topics across the remaining days. I tick topics done, and the unfinished ones automatically rebalance over the days still left. Let me mark some days as busy so it schedules nothing on them. Everything saves on my device, clean readable theme. Build the whole thing, check that it works, and tell me exactly how to open it.
✦✦

Say it in YOUR language — Russian, Spanish, anything. Claude understands.

Build it now — tick as you go

0/6

Step 2 — It's built. Now make it yours

ℹClaude said 'open localhost…' — now what?

Don't panic at the techy link. Claude tells you one of two things. Either a file like index.html — find it in your project folder and double-click it; it opens in your browser. Or a web address starting with http://localhost — copy it into your browser's address bar and press Enter. 'localhost' just means 'this is running on your own computer right now'. That's your tool. It's real.

Now tweak it until YOU like it — just talk

This is the part that makes it YOURS. Don't accept the first version — change it by saying what you want, right there in the same chat. Claude rebuilds and you refresh. Keep going until it fits how you actually work. For this tool, try things like:

you ▸ let me mark days I'm busy so it puts nothing on them and packs the rest
you ▸ show a big 'days left' number and a progress bar at the top
you ▸ mark some topics as harder so they get two days instead of one
✦How I (Evgenii) actually do this

I don't type long messages. I open voice-to-text (the mic in ChatGPT, or your phone keyboard), and just TALK through everything I think about what it built — what's wrong, what I want next — then select-all, copy, and paste the whole brain-dump into Claude Code. Messy spoken thoughts work fine; the agent sorts them out. It's several times faster than writing.

Step 2.5 — Test it like a real thing (it won't be perfect first try)

The truth no one tells beginners: the first build is a DRAFT. The agent makes something, you run it, you find what's off, you tell it — and THAT loop is the actual work. Don't read the code. Use the tool like a stranger would and watch where it lets you down. For this tool, check exactly this:

  1. 1Open it (Claude gives a localhost link or an index file — see Step 2), set an exam date about two weeks out and paste in eight to ten topics.
  2. 2Check the top: does 'days left' show the right number, and does the plan actually spread your topics across the days up to the exam — not dump them all on day one?
  3. 3Tick two topics done. Do the remaining ones rebalance over the days still left, and does the progress bar move? If the plan sits frozen, that's your first fix.
  4. 4Mark one day as busy. Does it clear that day's topics and push them onto the other days? An ignored busy-day flag is your next fix.
  5. 5Refresh the page (F5 / Cmd-R). Are your date, topics and ticked-off progress still there? If they vanish, 'saves on my device' isn't wired up — fix that next.

Found something wrong? Say it like this

You fix nothing yourself — you DESCRIBE what's wrong in plain words and the agent fixes it. Be specific: what you saw vs. what you expected. Real examples for this tool:

you ▸ 'when I tick a topic done the plan doesn't change — rebalance the unfinished topics over the days that are still left'
you ▸ 'marking a day busy still schedules topics on it — put nothing on busy days and pack them onto the free days instead'
you ▸ 'when I refresh the page my exam date and progress disappear — save everything on my device so it stays'

Don't stop at v1 — grow it

A tool you built in ten minutes is a starting point, not the finish line. The people who get hooked keep saying 'now also…'. Each line below is one sentence you paste into the same chat to level this tool up:

you ▸ 'let me mark some topics as harder so they get two days instead of one' — heavy topics shouldn't share a slot with easy ones.
you ▸ 'add a daily checklist view that shows only today's topics' — on the day, you want one short list, not the whole map.
you ▸ 'warn me in red if there are more topics left than days remaining' — an early heads-up that you need to cut scope or cram.
you ▸ 'show a second bar comparing planned days against days you actually studied' — honest feedback on whether you're keeping up.

Step 3 — Connect it to the world (optional)

Free data & APIs for this one

An API is just how your tool pulls in outside data or sends things out — many are free. You rarely need to research them yourself; the move that works for ANY idea is to ask the agent to find them:

  1. 1You need NO external API — the countdown, the day-by-day split and the rebalancing are all date math that runs locally on your device.
  2. 2If you later want each study day pushed into your phone's calendar, that's a Google Calendar connection (free tier) — but it's optional and not needed to start.
  3. 3Reusable move for ANY idea: ask Claude — 'look up free or open APIs that fit an exam study planner and tell me which actually need a key.' It will list them; you pick.

About paying for the AI parts

  1. 1Building the tool with Claude Code is covered by your Claude plan (Pro, Max, Team or Enterprise) within its usage limits.
  2. 2If the finished tool itself should call Claude (for example to write texts for you), it needs its own API key from the Claude Console, and that use is paid separately, per use.
  3. 3Prices change; check claude.com/pricing before you plan anything that runs often.
ℹWhich keys this tool can use

This tool needs no keys to be great — it runs entirely on your computer. Add one only if you later want it to reach out to a service.

Step 4 — Put it online (only if someone else needs it)

ℹStep 4 — Put it online (only if someone else needs it)

Just for you, on your computer? You're already done — skip this step with a clear conscience. Put it online only if someone ELSE should open it, or you want to reach it from your phone away from home.

Step 6 — Stay safe (two easy habits)

  1. 1Back up anything you'd hate to lose. If the tool holds real data (your budget, health log, client list), ask Claude early: 'add an export/backup button' — one click saves your data to a file. Do it before you ever rebuild from scratch or move the folder.
  2. 2Don't hand Claude the keys to dangerous rooms. Keep it pointed at this project's own folder. Never connect a learning project to your bank, your crypto, or anything irreversible. Receipts and calendars — yes. Savings — no.
  3. 3Think before you ask. Claude does what you say in the folder you're in. 'Optimize my photos' optimizes them; it won't delete them — unless you ask for something reckless. Sane requests, clean workspace, and there's simply nothing scary left.

The mistakes that stop most people

  1. 1Asking for something vague ('make me an app') and getting something vague back. Name the screens, the buttons, what gets saved.
  2. 2Cramming in ten features at once. Ask for the tiniest working version first — then grow it with follow-up requests.
  3. 3Stopping at the first error. An error isn't failure — paste it to Claude or describe what you see, and it fixes it. That loop IS the work.
  4. 4Deciding you need to 'learn programming first'. You don't need to understand the code Claude writes. You need to describe the result.
  5. 5Not saying what 'done' means. End the request with how you will check it, for example 'done when I can add an item and it is still there after I reload the page'.
  6. 6Building for an imaginary audience. Build the version YOU will open tomorrow. Polish never; use immediately.
!If something breaks

Normal. Tell Claude what's wrong in plain words ('the button does nothing', 'the page is blank') or paste the red error text. It finds and fixes it. You check. Repeat until it works.

checkpoint

That's it. You built a real tool.

You described the tool in words, Claude built it, and you checked it yourself. That is the whole loop, and it works the same for bigger tools.