Function forkSession

forkSession(
_sessionId: string,
_options?: ForkSessionOptions,
): Promise<ForkSessionResult>
Fork a session into a new branch with fresh UUIDs.

Copies transcript messages from the source session into a new session file, remapping every message UUID and preserving the parentUuid chain. Supports upToMessageId for branching from a specific point in the conversation.

Forked sessions start without undo history (file-history snapshots are not copied).
Parameters
- _sessionId: string
- Optional_options: ForkSessionOptions
Returns Promise<ForkSessionResult>
{ sessionId } — UUID of the new forked session
- Defined in node_modules/@anthropic-ai/claude-agent-sdk/sdk.d.ts:487