Function getMessagesSinceLastSummary

src/core/condense/index.ts:519–528

(messages: ApiMessage[])

 * so the first message since the last summary is guaranteed to be a user message.
 */
export function getMessagesSinceLastSummary(messages: ApiMessage[]): ApiMessage[] {
	const lastSummaryIndexReverse = [...messages].reverse().findIndex((message) => message.isSummary)

	if (lastSummaryIndexReverse === -1) {
		return messages
	}

	const lastSummaryIndex = messages.length - lastSummaryIndexReverse - 1
	return messages.slice(lastSummaryIndex)
}

/**
 * Filters the API conversation history to get the "effective" messages to send to the API.