appRequestError (30)

The appRequestError message is sent to signal a problem during the handling of a Mini-App request that prevents the session from starting. This is for errors beyond a simple user rejection, such as the app not being installed or a parameter being invalid.

Core Data Types

• IxiBytes: See IxiBytes Encoding.
• IxiVarInt: See IxiVarInt Encoding.
• string: A standard UTF-8 encoded string.

Payload Structure

Field	Data Type	Min	Max	Description
sessionId	IxiBytes	*	*	The unique identifier from the original appRequest message.
errorCode	IxiVarInt	0	*	An application-defined integer code for the error.
errorMessage	string	0	*	Optional. A human-readable description of the error.

Behavioral Notes

• Usage: A client sends this if it receives an appRequest but cannot proceed for a technical reason (e.g., requested app is not installed, initial data payload is malformed).
• Session Termination: Like appRequestReject, this message definitively terminates the session setup process.