Errors and cancellation

The SDK separates browser transport failures from structured Keymaster rejections.

import {
  KeymasterProtocolError,
  KeymasterTransportError
} from "@keymaster/connect";

try {
  await keymaster.resume(sessionId);
} catch (error) {
  if (error instanceof KeymasterProtocolError) {
    console.log(error.code, error.message);
  } else if (error instanceof KeymasterTransportError) {
    console.log(error.code);
  }
}

Protocol rejection

KeymasterProtocolError means a valid result was received with ok: false. Switch on error.code; do not parse the English diagnostic message.

User cancellation, local payment failures, and several policy failures are intentionally collapsed so callers cannot infer sensitive wallet state.

Transport failure

KeymasterTransportError describes popup blocking, window closure, readiness timeouts, request timeouts, appView opener loss, or a local client shutdown. These errors do not imply that a persistent Connect session has been revoked.

AbortSignal

const controller = new AbortController();

const result = keymaster.request(
  "identity.get",
  params,
  { requestId: crypto.randomUUID(), signal: controller.signal }
);

controller.abort();

Aborting rejects the local promise immediately and sends a best-effort cancel control message. Keymaster can cancel queued or confirming work; executing work is not compensatable.