~/blog $ cd gas-city/
[series · 7 parts]
Building with Gas City
This is a seven-part tutorial about building a working web app while learning Gas City. Each part adds something new on top of the last. By the end you have an RSS reader of your own and a mental model for how Gas City fits into a project.
If you have used coding agents in your editor (Claude Code, Cursor, Codex), you already have most of the muscle this tutorial asks for. Gas City sits one level above that: instead of one agent helping you in your editor, you orchestrate several agents from the command line, each with its own role, and watch them deliver a feature together.
What we are building
A minimalist Hacker-News-style RSS aggregator. It fetches the HN front-page feed, stores items in SQLite, renders them in a simple page, and ships small features along the way (per-source labels, search, a daily LLM-generated digest). The app is written by agents under your direction. The configs you write to direct them are the artifacts you keep.
- A small Hono app on Bun, with
bun:sqlite,hono/html, and HTMX. - Five agents in your city: a mayor (always-on coordinator), a backend specialist, a DBA specialist, a frontend specialist, and a code reviewer.
- Three scheduled jobs: a periodic feed fetch, a nightly database prune, and a daily AI-written digest.
The stack is deliberately self-contained: no build step, no bundler, no JSX transpilation, no Tailwind toolchain. Bun runs .ts files directly, bun:sqlite is built in, hono/html is server-rendered, HTMX adds interactivity without leaving the server. Less to configure means less for the agents to get wrong.
- 00 Installation and setup
Set up your Gas City workspace, install the toolchain, and verify everything is working before building a multi-agent RSS reader.
- 01 Starting the mayor and sending mail
Wake the mayor, write its prompt, and exchange your first piece of mail with a live agent.
- 02 Your first backend agent
Register a backend specialist, hand the mayor its first feature, and watch a polecat spawn, work, commit, and drain.
- 03 Multi-specialist chains and bead dependencies
Register DBA and frontend agents, hand the mayor a real multi-lane feature, and watch a bead dependency chain run hands-off.
- 04 Adding a code reviewer
Add a reviewer agent, optionally run it on Codex, wire a mandatory review bead at the end of every feature chain, and watch it catch a real defect.
- 05 Scheduled orders and custom formulas
Add scheduled orders, write a custom formula that generates a daily AI digest, and think through how this maps to a real deployment.
- 06 Full-text search, end to end
One handoff, no nudges. Watch all four specialists run a full-text search feature from decomposition to reviewer approval.