shouldivibecodeit

Should I vibe codePortfolio Coach?

Family portfolio tracker with live valuations, UK planning tools, and AI reviews

Tracking your portfolio is fine. The moment it says “you should”, you have built advice.

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Their verdict, the AI credits price and the build-time estimate come from their entry, MIT-licensed. Checked 2026-08-03.

Can you build it?asked by canivibecodeit.com ↗KINDAweekend project · weekend for a local version, multi-day for the hosted product
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Our verdict, the regret score and everything below it. Editorial and unsponsored — nobody can pay to be moved.

Should you ship it?asked by usDEMO ONLYvibe the v0, throw it away.

The honest answer

why the verdict is what it is

Pulling valuations and charting them is a good project. Keep it descriptive: a homemade tool that makes planning recommendations is a tool you will trust more than it deserves.

What actually breaks

not "if". the specific failures.

  • The line between tracking and advice, which is a regulatory boundary rather than a product decision
  • Price data licensing, where market data feeds have redistribution terms and 'free API' rarely means free to show other people
  • Corporate actions — splits, dividends, mergers — which silently make a historical position wrong if unhandled
  • Tax logic, which is jurisdiction-specific, changes annually, and is the part people most want automated
  • Family access, so a spouse or an adviser can see holdings, which turns a personal tool into a multi-user one holding financial data
and then, at 3am

The tracker shows a healthy return. It has not handled the three-for-one split from March, so the historical cost basis is still per pre-split share while the current price is post-split — the position looks like it tripled. You make a decision based on it. The correction is arithmetic and takes a minute; the trade you already placed on the strength of the wrong number is not undone by fixing the display.

Is that you?

the verdict is a default, not a law

ship it if
  • It tracks and reports, and offers no suggestions about what to do
  • Positions are entered manually and prices are for your own display only
  • It is a single-user tool and you know the limits of its arithmetic
don’t ship it if
  • It recommends actions, allocations or rebalancing to anyone
  • Corporate actions are unhandled but historical returns are displayed
  • You are redistributing market data to other people
  • It calculates tax positions people would file from

If you build it anyway

the checklist, then the prompt that enforces it

  1. Draw the advice line explicitly and stay on the tracking side. Describing a portfolio is not the same activity as recommending changes to it, and the difference is regulatory.
  2. Read the licence on any market data source before displaying it to anyone but yourself. Redistribution is usually the restricted part.
  3. Handle splits, dividends and mergers or refuse to display historical returns. Half-handled corporate actions produce confidently wrong numbers.
  4. Label tax figures as estimates, cite the rule you applied, and tell people to check with an accountant.
  5. If anyone else can see it, that is multi-user financial data — authenticate properly and decide who sees what.
  6. Show the data's timestamp and source next to every valuation.
the guardrail prompt
Before you build a portfolio tracker, apply these and push back if I ask you to break them.

1. Ask me whether this will suggest what to do — buy, sell, rebalance,
   allocate. If yes, tell me that is the line between tracking and advice, that
   the line is regulatory in most jurisdictions, and recommend staying on the
   tracking side.
2. Check the licence terms of any market data source before displaying prices
   to anyone other than me. Explain that redistribution is normally the
   restricted right, and that a free API is often personal-use only.
3. Handle corporate actions — splits, reverse splits, dividends, mergers,
   spin-offs — before displaying any historical return. If they are not
   handled, refuse to show historical performance and say why.
4. Represent money and share quantities as integers or decimals, never floats,
   and store the currency with every amount.
5. Label all tax calculations as estimates, state which rule and which tax year
   was applied, and tell the user to verify with an accountant. Do not produce
   figures that look filing-ready.
6. Show the source and timestamp of every valuation next to the number.
7. If family members or an adviser will have access, treat this as multi-user
   financial data: real authentication, per-user visibility, and an audit of
   who saw what.
8. Never store brokerage credentials. Manual entry or file import only.
9. Out of scope unless I ask: automated trading, performance benchmarking
   against indices, retirement projections.
paste this before you build — not after something breaks24 lines · 1519 chars

That one keeps you out of trouble. For the prompt that actually builds it, canivibecodeit.com has one.

their build prompt ↗

Or don’t build it

the boring option, and the way back out

just pay for it

The corporate actions and licensed price data are the parts worth paying for, because both produce silently wrong numbers when done casually. A manual tracker that reports positions honestly and stops short of advice is a sound personal project.

your exit plan, if you already built it

Keep positions, transactions and corporate actions as exportable rows with dates and currencies — the transaction history is the asset, and prices can always be re-fetched. Anything the tool computes should be reproducible from that history rather than stored as a result.

prior art · someone already did this
Ghostfolio

Open-source wealth management software with portfolio analytics

Portfolio Performance

Open-source desktop portfolio tracker with detailed performance analysis

Questions

Where exactly is the line between tracking and advice?

Roughly: describing what you hold and what it is worth is tracking; suggesting what you should do about it is advice. Rebalancing prompts, allocation targets and 'you are overweight in X' sit on the advice side in many jurisdictions. The specifics vary, which is itself a reason for a personal project to stay well clear of the boundary.

Why do corporate actions cause such confident errors?

Because they change the meaning of historical data without changing its shape. After a split, old prices and quantities are still valid numbers — they are simply in different units from current ones. Nothing looks malformed, so no validation catches it, and the resulting return figure is plausible enough to act on.

did you build it?

Every week, someone ships something they shouldn’t have.

New verdicts, the worst thing that landed in the trap, and the occasional incident report. No other email, ever.

also on the regret index
YNABDEMO ONLY

Your own budget, your own rules, your own bug that told you you had money.

last reviewed 2026-08-03 · verdict is editorial and unsponsored · shared entry data from canivibecodeit under MIT · not legal advice