What is GemmaPod?

The one-paragraph version

GemmaPod is an open-source SDK for building portable AI agents. You describe an agent in a TOML file (its persona, system prompt, model preference, allowed tools), sign it with an Ed25519 key, and the CLI turns it into a single self-contained HTML file the recipient can open in any browser. The pod knows how to phone home to a Gemma 4 model running on your machine, and if you're offline it knows how to run Gemma 4 entirely in the visitor's browser via WebGPU.

You can think of it as the vCard for AI agents — except the agent is you (or your product, or your assistant), and the vCard runs a real language model.

What's actually inside a .html pod

Three inlined assets:

1. Signed manifest (~3 KB) — Ed25519 signature over a CBOR-encoded manifest body. Identity, persona, system prompt, model preference, transport config, allowed tools.
2. WASM core (~228 KB) — Rust compiled to WebAssembly. Signature verification, manifest parsing, DARTC byte signing. The exact same WASM runs in the browser AND in Node (@gemmapod/toolkit and @gemmapod/signal use it server-side too).
3. Shim (~342 KB) — Preact widget + GemmaPodRuntime (event bus, state store, capability registry) + three transports (WebRTC, in- browser fallback, direct HTTP for dev). The WASM is inlined as a data:application/wasm;base64 URL inside the shim, so a single <script> tag carries the entire runtime.

Total: ~960 KB. Email-attachable, CDN-cacheable, fits in a tweet about its own size.

What happens when you open one

1. The browser loads the .html.
2. The shim initialises the WASM core (no network).
3. The WASM verifies the signed manifest. If it doesn't pass, the page shows a red gemmapod refused to mount error — no persona, no prompt, nothing the attacker can use.
4. The runtime walks the transport list: try WebRTC to the owner's origin, then in-browser WebGPU fallback, then a direct HTTP endpoint (dev only).
5. The first transport whose handshake succeeds wins. Chat begins.

What this SDK is, and isn't

It is an SDK for shipping portable AI agents — one Rust/WASM crypto core, one TypeScript runtime, one Preact widget, one CLI, one signaling broker. Take what you need; the surface is intentionally small.

It isn't an inference engine. Gemma 4 inference happens via Ollama (on the owner's box) or transformers.js + WebGPU (in the visitor's browser). The SDK is the envelope and the courier.

It isn't a chat platform. There's no "GemmaPod cloud" you're forced to use. The reference signaling broker (@gemmapod/signal) runs on your VM in 30 lines of code. The default registry is in-memory; the production registry is whichever storage backend you want behind the four-method Registry interface.

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