Baggage-fee booking checker

You are a senior product engineer. Turn the product idea below into a locally runnable MVP.

## Idea

Baggage-fee booking checker
Helps family travelers check baggage fees before booking so low fares do not become expensive.

## Product concept

Build a single-page tool where users enter a route, airline, fare class, whether they are checking bags, and their carry-on bags. The tool returns the baggage-fee items that may apply to that combination, along with links to official rules and a checklist that users can save. In the typical summer family-travel scenario, a parent compares flights on Google Flights, Kayak, or an airline website and views the low fare and baggage needs in one table. This differs from existing approaches by preserving the checking process and official-rule evidence instead of only displaying a flight price or a static fee chart.

## Why now (backed by facts)

The DOT’s July rule moves first-screen baggage-fee notices and consolidated disclosures back to the front of the booking path. Travelers will more often check “fare plus baggage” instead of looking only at the base fare.

## Direction (model inference, not independently verified)

Target user: US travelers booking summer trips for a family or group who need checked bags but are unfamiliar with individual airline rules.

Minimal entry point: Start with a web version. Do not collect fares across the web. Support manual entry for the airline, fare class, number of bags, and passenger type. Cover only common US airlines, and bind each rule to the update date of its official page. Cut automatic booking, real-time fares, and complex loyalty-benefit determinations.

The strongest case against: The weakest assumption is that travelers will leave a booking platform to use a separate tool. DOT rules may lead airlines and OTAs to display fees directly on the first screen, which could reduce the use case for a third-party checker.

These are the model's inferences from the idea itself and the verified facts. Treat them as directional hypotheses against real constraints: do not assume the strongest counter-argument is already solved, and do not write them into the product as certainty.

## Punching above weight (model inference)

Create SEO pages for queries such as “airline name + baggage fee + fare class” and “checked baggage fee check.” Share checklists in travel-planning forums, family-travel blogs, and credit-card travel communities, where people tend to research baggage rules before booking.

## Competitors & gaps (model inference)

- Google Flights: It focuses on sorting flight searches. It does not save baggage-fee checks across airlines and fare classes or preserve evidence from official rules.
- Kayak: It serves booking conversion. It is not suited to rule traceability independent of the ticket seller or to checking disputes after booking.
- Airline Baggage Fee Charts: Static tables struggle with combinations of fare class, route, and passenger identity. They also do not turn the checking process into a savable travel checklist.

## How it makes money (model inference)

The first payment comes from travelers about to buy tickets for multiple people. They pay to unlock export when they generate a printable baggage-fee checklist, an archive of official links, and a comparison table for traveling passengers.

## Sources

- https://www.transportation.gov/airconsumer/latest-news

## Deliverables

- Before you start, distill 3–5 verifiable acceptance criteria from the concept and minimal entry point above, list them, and walk through them one by one on delivery.
- Ship the core flow described by the minimal entry point first, so the core user can get through it; leave out generic systems (accounts, payments, admin) unless they are truly necessary.
- Do not show unverified market numbers in the UI or API.
- Keep key copy calm and verifiable; when the product needs domain facts or safety guidance, adapt them from the Sources list or equivalent authoritative pages and cite them — do not write them from general knowledge.
- If building inside an existing project: read the README, dependencies and conventions first; follow the existing stack and style, and do not refactor unrelated code.
- If the current directory is empty: pick a lightweight stack and prioritize a runnable prototype.
- When done, explain what changed, how to run it, and how to verify it.
- Ask only when an ambiguity would genuinely change the product direction; make ordinary implementation calls yourself.

Helps family travelers check baggage fees before booking so low fares do not become expensive.

Published July 7, 2026 · 1 source

Build a single-page tool where users enter a route, airline, fare class, whether they are checking bags, and their carry-on bags. The tool returns the baggage-fee items that may apply to that combination, along with links to official rules and a checklist that users can save. In the typical summer family-travel scenario, a parent compares flights on Google Flights, Kayak, or an airline website and views the low fare and baggage needs in one table. This differs from existing approaches by preserving the checking process and official-rule evidence instead of only displaying a flight price or a static fee chart.

Why now

The DOT’s July rule moves first-screen baggage-fee notices and consolidated disclosures back to the front of the booking path ^S1. Travelers will more often check “fare plus baggage” instead of looking only at the base fare.

Target user

US travelers booking summer trips for a family or group who need checked bags but are unfamiliar with individual airline rules.

Minimal entry point

Start with a web version. Do not collect fares across the web. Support manual entry for the airline, fare class, number of bags, and passenger type. Cover only common US airlines, and bind each rule to the update date of its official page. Cut automatic booking, real-time fares, and complex loyalty-benefit determinations.

Punching above its weight

Create SEO pages for queries such as “airline name + baggage fee + fare class” and “checked baggage fee check.” Share checklists in travel-planning forums, family-travel blogs, and credit-card travel communities, where people tend to research baggage rules before booking.

Competitors & gaps

Google Flights: It focuses on sorting flight searches. It does not save baggage-fee checks across airlines and fare classes or preserve evidence from official rules.
Kayak: It serves booking conversion. It is not suited to rule traceability independent of the ticket seller or to checking disputes after booking.
Airline Baggage Fee Charts: Static tables struggle with combinations of fare class, route, and passenger identity. They also do not turn the checking process into a savable travel checklist.

How it makes money

The first payment comes from travelers about to buy tickets for multiple people. They pay to unlock export when they generate a printable baggage-fee checklist, an archive of official links, and a comparison table for traveling passengers.

The case against

The weakest assumption is that travelers will leave a booking platform to use a separate tool. DOT rules may lead airlines and OTAs to display fees directly on the first screen, which could reduce the use case for a third-party checker.