Every developer has a localhost. This one is San Antonio.
San Antonio has an API. Three, actually: Bexar County, the City and VIA publish their data in the open, free, no key required. Every dot here is one record: a building from 1896, a permit from this year, a bus stop.
localhost:210 is DEVSA's open-data project, named for the port every developer knows and San Antonio's area code: starter code for each source, a guide to what they publish, and the three pieces below, built with them. Fork it and build something.
01 · Bexar County open data
Follow the water. San Antonio, 1718 to today.
Before San Antonio had streets it had acequias, irrigation ditches dug from the river and San Pedro Creek. Bexar County has mapped every one, with the year it was dug and the year it went dry, along with the fields and land grants they fed. Scroll, and three centuries pass over downtown: each ditch appears in the year the County dates it and fades in the year it was abandoned.
Before 1718
Before 1718
First, water.
Before there was a city there was the San Antonio River and San Pedro Creek, both fed by springs a few miles north of downtown. Everything that follows is about getting their water to where people lived.
1718
A presidio, a mission, and ditches.
In 1718 Spain founded the Presidio de Béxar and Mission San Antonio de Valero, later called the Alamo. The County dates the first acequias to that same year: the Acequia Principal and the San Pedro. A third, the Segundo, was abandoned a year later.
1720 – 1731
Down the river, four more missions.
Concepción, San José, San Juan and Espada lined the river to the south, each with its own acequia, dug by the Native people who lived and worked at the missions. Watch them reach out from the river one by one.
1731
The Canary Islanders.
In 1731 families from the Canary Islands arrived to found the Villa de San Fernando, San Antonio's first civil town, and were granted lots between the creek and the river. Hover a lot to read whose it was.
1734 – 1794
Ditches made fields.
The land along each acequia was split into long farm lots, the labores. The County maps 348 land grants, each with its grantee and year. Hover one.
1776 – 1912
The city covers the water.
The Upper Labor ditch, dug from 1776, was the last big one. As the city piped in its water, the ditches went dry one by one: Concepción's in 1869, the Upper Labor in 1896, the Principal and the Alamo's in 1905, the San Pedro in 1912. By 1896 the Sanborn map shows downtown built over them. Look at where the blocks bend.
Today
Geekdom's corner.
Ask the County
GET …/RullmanAcequia/FeatureServer/0/query
?geometry=-98.49337,29.42637&distance=400
&outFields=Name,YrCreate,YrAband
Build your own
The County publishes more than 300 map layers: the acequias, missions and land grants of the 1700s, cattle drives and railroads, 15,349 buildings from 1896, 4,200 places from 1897, and every district map from Congress to your voter precinct. The starter tells you which acequias ran near any point, and maps them all with a year slider.
Data: Bexar County Information Technology GIS (Tricentennial historical layers: river, acequias, labores, land grants, missions and presidio; 1896 Sanborn maps). Today: the DEVSA community calendar, as of October 25, 2026. Grantees are named as the County records them. A DEVSA project, not affiliated with Bexar County.
02 · City of San Antonio open data
Watch downtown get built. Every permit since January 2025.
Before anyone builds, remodels or rewires downtown, the City issues a permit, and it publishes every one. This is 2,864 of them, lit in the order they were issued, on the City's own map of its streets. Click a spot and the page asks the City's API what's being built there, live from your browser, and shows you the request.
What's being built?
Click anywhere on the map, or pick a place. You'll get every permit the City has issued there since January 2025, straight from its API: what the work is, when it was issued and how long that took.
Build your own
Every permit citywide, with its type, dates, declared value and square footage, and next to it 311 service calls, fire inspections, street and sidewalk projects and low-water crossings. The starter sends the same SQL as the map above for any point you give it, and says how long each permit took.
Data: City of San Antonio Open Data, CC BY 4.0 (permits issued, through October 23, 2026); street centerlines from Development Services and Public Works. Permits name a primary contact, often a private person; this page never asks for it, and shows homes by their block. A DEVSA project, not affiliated with the City of San Antonio.
03 · VIA open data
Outrun the 4. On VIA's real schedule.
VIA publishes every trip its buses make, stop by stop and to the second. Press Run and you're at Navarro & Houston, a block from Geekdom, with the next real Route 4 one stop behind you. The bus keeps its timetable, 24 times faster; you run 4% faster than it can average, so a clean run wins. Beat it up San Pedro to as many stops as you can.
Next stop…
To go0.22 mi
Route 4 · 0.26 mi behind you
How to play
Jump the cones, puddles and scooters. Each one you hit costs you a beat, and the bus doesn't wait. It's slow through downtown and fast up San Pedro, exactly as VIA schedules it, so build your lead early.
Build your own
6,098 stops, 88 routes and every scheduled trip through January 10, 2027, in GTFS, the format every transit app reads, plus where the buses are right now as GTFS-realtime. The starter tells you when the next bus leaves any stop.
Data provided by VIA Metropolitan Transit: the published GTFS schedule, version August 2026. Bus times are VIA's; the runner, the sidewalk and the speed-up are the game. A DEVSA project, not affiliated with VIA.
Build with us
Your turn. The data is open, and so is the code.
Each starter is one Python file that asks one source a real question. These three match the pieces above; the repo has more, from the 1897 city directory to 311 by district. Run one, change the question, and add what you make to the repo's showcase. SOURCES.md covers everything the three publish, and their terms.
Bexar County
Acequias. Which Spanish irrigation ditches ran near any point, when each was dug and when it went dry, and a map of all of them with a year slider.
starters/acequias
City of San Antonio
Permits near you. Every building permit around a point since 2025, biggest first, with how long each took to issue. One SQL query.
starters/permits-near-you
VIA
VIA next bus. Type part of a stop's name and get its next departures, from the published schedule.
starters/via-next-bus