Where to Get Data for Vibe Coding: 9 Free Public Data API Sources

TL;DR: When building apps or automations with AI, the most common bottleneck isn’t coding. It’s “Where do I get the data?” Six Korean public data portals and three API collections cover the data most ideas need, for free. I personally checked that every site listed here was accessible at the time of writing.

Contents

1. You Get Stuck on Data, Not Ideas
2. 6 Public Data Portals in Korea
3. 3 API Collections and Marketplaces
4. Pro Tip: Let AI Pick from the List
5. 3 Things to Know Before You Start

You Get Stuck on Data, Not Ideas

The point where people trying to build something with vibe coding actually stall is surprisingly consistent. They have something they want to make, but they don’t know where to find the data to fill it. Ideas like “neighborhood apartment price alerts,” “outfit suggestions based on the weather,” and “farm produce price tracking” all depend on data as the raw material. You can’t start cooking without ingredients.

Fortunately, Korea has well-organized public data. If you know the list below, most of the ingredient worries disappear.

6 Public Data Portals in Korea

Name	Address	What data	Notes
Public Data Portal (data.go.kr)	data.go.kr	Public data across Korea in general, including weather, transportation, real estate, and population	The gateway to Korean public data. Free; requires an authentication key
Seoul Open Data Plaza	data.seoul.go.kr	Seoul transportation, Ttareungyi (Seoul’s public bike-sharing system), commercial areas, population	Limited to Seoul, but the data is dense
KOSIS (Korean Statistical Information Service)	kosis.kr	Nationally approved statistics on population, employment, prices, and more	Statistical tables are provided as APIs themselves
KMA API Hub (Korea Meteorological Administration)	apihub.kma.go.kr	Current conditions, forecasts, and past weather observations	Start here for weather ideas
Bank of Korea ECOS	ecos.bok.or.kr	Economic statistics such as interest rates, exchange rates, and money supply	The classic source for economic indicator visualizations
KAMIS (agricultural product distribution information)	kamis.or.kr	Wholesale and retail prices of farm, livestock, and fishery products	Useful for grocery and price-alert ideas

All six are free. Most require you to sign up and get an authentication key (API key), but you only need to do this once.

3 API Collections and Marketplaces

For data that isn’t on the portals, look in the collections.

Name	Address	Use
public-apis-4Kr	github.com/yybmion/public-apis-4Kr	A repository of APIs that work with Korean services. Start here when looking for Korean APIs
public-apis	github.com/public-apis/public-apis	The de facto standard list of free overseas APIs. Use it when you need global data
RapidAPI	rapidapi.com	A marketplace for free and paid APIs. Search and test on one screen

Pro Tip: Let AI Pick from the List

The real value of this list is something else. Give the addresses above to an AI (Claude, ChatGPT, etc.) and try asking:

“I’m building ○○. Find the right API for it in this list. Also summarize whether it’s free, what the call limit is, and what data it provides.”

You don’t have to dig through each API doc. The AI will narrow down candidates and organize them into a comparison table. Handing off the search for data sources to AI itself is what a vibe-coding start looks like. If you don’t have a development environment ready to call the API you choose, first set up the Claude Code CLI.

3 Things to Know Before You Start

1. Some API keys take time to issue. Some are issued immediately, but others take a day or two to approve. Apply the day before you start building so your momentum doesn’t stop.
2. Check the call limits. Most free APIs cap calls per day. That’s enough for personal projects, but automations that call repeatedly need to be designed within the limit.
3. Read the terms of use once. Public data can mostly be used freely, but some come with attribution requirements.

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If you want to talk about what to build with this data, drop by the open KakaoTalk chat room Making a Living with AI. (KakaoTalk is South Korea’s dominant messaging app.) Members are sharing experiments built on these data sources.