Errors

Callx reports problems in two ways:

• Results. Known outcomes of a command (rejected, timed out, unknown) resolve normally with a CommandResult whose error explains it.
• Exceptions. Validation and transport problems throw: CallxError in TypeScript, CallxException in Dart. Native rejections can also surface as the framework's own error types; read the code when present.

try {
  const result = await callx.answer(callId);
  if (result.status !== 'applied') handle(result.error);
} catch (error) {
  handleThrown((error as {code?: string}).code);
}

Error codes

Code	When	Retryable
invalidArgument	Malformed input, a limit exceeded, a deadline more than 30 s away, or a contract version mismatch between native and framework code	No
notConfigured	No native runtime is installed: the bootstrap did not run or failed	No
nativeUnavailable	The native module is missing (not rebuilt, web, Expo Go), or the platform reset before completing	Yes
callNotFound	No live call has this callId	No
busy	startCall while another call is live	No
invalidState	The call's state does not allow the command: answering a call that is not incoming, holding a call that is not active, starting a call with an ID that already ended	No
unsupported	The runtime lacks the capability, for example no outgoing-call starter on Android	No
platformRejected	CallKit or Core-Telecom refused the action. error.platform has the diagnostic {domain, code}	Depends
mediaNotReady	The media engine could not apply mute	Yes
deadlineExceeded	Paired with status timedOut	Reconcile first
conflict	The operationId was already used with different arguments	No
internal	An unexpected native failure	Report it
permissionDenied	Reserved; not emitted in this version
journalGap	Reserved; not emitted in this version

retryable on the error is authoritative. Retry with the same operationId.

Platform details

error.platform is for logs and diagnostics, not control flow. Domains include CallKit's CXErrorCodeRequestTransactionError and CXErrorCodeIncomingCallError codes on iOS and Core-Telecom's CallException codes on Android. They can change between OS versions.

Messages

error.message is English, for developers, and never contains personal data such as names, handles or tokens. Show your own text to users.