Creating a handoff

import { createHandoff } from "@0xsarwagya/handoff";
 
const handoff = createHandoff({
  receiveUrl: "https://app.example/receive",
});
 
const offer = await handoff.create({
  type: "draft",
  version: 2,
  text: "finish this on my phone",
});

The offer is everything you need to move the state:

offer.url;        // https://app.example/receive#handoff=ho1_…
offer.artifact;   // the bare ho1_… string — render it as a QR code
offer.size;       // serialized state size in bytes
offer.qrFriendly; // true while the artifact will scan reliably
offer.transport;  // "inline" — the state travels inside the artifact

Show offer.url as a link, copy it to the clipboard, or render offer.artifact as a QR code — those are three representations of the same transfer, not three transports.

Size limits

Inline transfer is for small state. create rejects anything whose JSON exceeds the limit (default 8 KiB) with PAYLOAD_TOO_LARGE — before generating an artifact nothing can scan:

await handoff.create(bigState, { limit: 16384 }); // explicit opt-up

offer.qrFriendly flips false past ~1,000 artifact characters — links still work fine there, but cameras stop cooperating. See size limits for the physical reality behind the numbers.

What state can travel

JSON-compatible values only: null, booleans, finite numbers, strings, arrays, plain objects. Dates, Maps, class instances, NaN, and cycles are rejected with ENCODING_FAILED instead of being silently reshaped — if JSON would corrupt it, Handoff refuses it.