A deep dive into SpacetimeDB's TypeScript SDK and how to wire it into a Next.js 15 App Router application for live visitor tracking and realtime features.
3 min readCurrent systems
Active work,
live signals, and writing.
Featured builds, the latest ranked signal, and recent writing — all in one place.
Featured build
MAINFRAME
Open-source bash stdlib for AI agents. Signals systems-level engineering range. Shows open-source authorship.
Pure bash runtime · Agent working memory primitives
Latest ranked signal
Async I/O in Zig 0.16, today
Comments
LOBSTERS · 2h ago · score 62
Publishing system
Building Realtime Apps with SpacetimeDB and Next.js 15
A deep dive into SpacetimeDB's TypeScript SDK and how to wire it into a Next.js 15 App Router application for live visitor tracking and realtime features.
3 min read · spacetimedb · next.js
Open-source ecosystems
Projects I support
Small but important signal: I contribute to and support AI-native developer tooling beyond my own products.
✦ Selected Work
Systems I've Built
Ranked signal feed
Full feed →LOB· 2h ago↑ RISING
Async I/O in Zig 0.16, today
62
devsystemsSIMON· 6h ago↑ HOT
Warelay -> OpenClaw
68
aidevLOB· 8h ago↑ RISING
Subscription Bombing: Email under Attack
62
devsystemsTC AI· 6h ago↑ RISING
The haves and have nots of the AI gold rush
56
aitechSIMON· 10h ago↑ HOT
Quoting Julia Evans
68
aidevTC AI· 8h ago↑ RISING
Research repository ArXiv will ban authors for a year if they let AI do all the work
56
aitech✦ /now
What I'm Doing
Right Now
Building
ACTIVE
PropertyJunk.com — junk removal SaaS platform
ACTIVE
TaxScout.app — commercial real estate tax optimization
WIP
MAINFRAME — open source bash stdlib expansion
WIP
toddwatts.dev — this site
Reading
01Attention Is All You Need (re-read)
02The Pragmatic Programmer — 2nd ed.
03Designing ML Systems — Chip Huyen
Watching
▶
Andrej Karpathy
Neural nets: Zero to Hero
▶
Lex Fridman
Sam Altman ep.
▶
ThePrimeagen
Rust streams
My Setup
EditorVS Code + Claude Code
AIClaude Sonnet 4.5, Pi
RuntimeBun 1.2
DeployVercel






