Configuration

Field	Type	Description
environment	'sandbox' | 'production'	Required. Selects sandbox.safaricom.co.ke or api.safaricom.co.ke.
consumerKey	string	Required. From your Daraja app.
consumerSecret	string	Required. From your Daraja app.
passkey	string	The Lipa na M-Pesa Online passkey. Required for stkPush.
initiator	Initiator	The API operator. Required for B2C, Transaction Status, Account Balance and Reversal. See Certificates.
tokenStore	TokenStore	Where access tokens are cached. Defaults to memory. See Token store.
timeoutMs	number	Per-request timeout. Defaults to 30 000.
fetch	typeof fetch	The fetch implementation. Defaults to the global fetch.
onWarning	(message: string) => void	Receives non-fatal warnings, such as an expired certificate.

createMpesa validates the configuration and throws a ValidationError listing every problem.