An AI PCB designer that talks to your AI.

Circuitcaster is the first PCB design tool built AI-native from day one. Point Claude in Chrome, ChatGPT Operator, Gemini in Chrome, or Perplexity Comet at app.circuitcaster.com and prompt for whatever circuit you want. Zero prompt engineering. Any browser-driving AI can design a real schematic on it.

How it works

Two artifacts make Circuitcaster AI-native:

1. /llms.txt at app.circuitcaster.com/llms.txt — a machine-readable manual documenting the app's data model, driving API, recommended agent loop, and downstream KiCad-to-Gerbers pipeline. Every browser-driving AI reads it on arrival.
2. window.CIRCUITCASTER JavaScript surface — the running app exposes semantic verbs (setLevel, addPin, addWire, moveComponent, saveToProject, etc.) plus getState(), getSchema(), dispatch(), and observe(). Any AI can inspect state and drive actions without synthesizing touch events.

Which AIs work with it

• Claude in Chrome — Anthropic's browser-driving Claude extension. Currently the gold standard for driving Circuitcaster; the reference case study was built with Opus 4.8.
• ChatGPT Operator / Atlas — OpenAI's agent-native browser. Same shape as Claude in Chrome; can read /llms.txt and drive window.CIRCUITCASTER identically.
• Gemini in Chrome — Google's Gemini agent baked into Chrome. Widely available.
• Perplexity Comet — Perplexity's agent-native browser.
• Any Playwright + LLM stack — Kimi K2.6, Hermes 4, DeepSeek V3, Llama 4, Qwen 2.5, Mistral. Because the moat is the site, not any specific AI, cheap models with browser automation drive Circuitcaster too. Cost-per-session approaches zero as models get cheaper.

Try it — sample prompts

Paste any of these into your AI's browser side panel:

Design a classic 555 timer astable LED blinker circuit in Circuitcaster.
Please open https://app.circuitcaster.com and follow the /llms.txt manual.
Standard astable values (R1=10k, R2=100k, C1=10uF, LED with 330Ω).
Organize the schematic so wire crossings are minimal — don't try to
eliminate every crossing, just keep them as few as possible.

Design an ATtiny85 Hello World blink circuit in Circuitcaster. Please
open https://app.circuitcaster.com and follow the /llms.txt manual.
Make the schematic wires well-organized so they don't cross too much.

Design a solar-powered USB cell phone charger circuit in Circuitcaster.
Input: a 12V solar panel. Output: USB-A 5V at up to 1A. Use an LM2596
step-down buck converter with standard support components (input bulk
cap, output smoothing cap, inductor, Schottky flyback diode). Add a
reverse-blocking Schottky on the input. Feed the 5V to a 4-pin USB-A
header. Please open https://app.circuitcaster.com and follow the
/llms.txt manual. Minimize wire crossings.

Why this is the moat

Traditional PCB tools were built assuming a human at a desk with a mouse. Every design decision — menus, keyboard shortcuts, hover tooltips — assumes an operator with intent and knowledge. When you point an AI at those tools, it stumbles: the interface was never meant for it.

Circuitcaster was built the other way. The same API a human's mouse triggers is available to an AI as CIRCUITCASTER.dispatch(). The same state a human reads off the canvas is available as CIRCUITCASTER.getState(). There's no wall between "human mode" and "AI mode" — there's just the app, and anyone (human or AI) can drive it.

Which means: every future browser AI drives Circuitcaster for free. Instrument once, ride the wave.

Frequently asked questions