--- title: Branching description: Explore alternative conversation paths without losing context --- Branching lets you fork a conversation at any message and explore another direction without replacing the original path. Editing a message or generating another response creates a sibling that you can return to later. Navigating between conversation branches ## How it works Every message has a parent, which forms a conversation tree. ChatJS displays one root-to-message path at a time while keeping the other branches available. ```mermaid flowchart TD U1[User: Plan a launch] --> A1[Assistant: Start with architecture] A1 --> U2[User: Make it technical] U2 --> A2[Assistant: Define service indicators] U2 --> A3[Assistant: Use staged environments] ``` The selected message is the cursor. Sending a message continues from that cursor, so selecting an earlier node before sending creates a new branch. ## Navigate branches When a message has siblings, arrow controls show the current position, such as `2/3`. Use the arrows to move to the previous or next branch. Switching branches: - changes the active conversation path - preserves responses that are still streaming on other branches - clears transient data that belongs to the previous path - closes an open artifact when its message is not in the selected path - follows the selected branch to its latest descendant ## Edit a message Editing creates a replacement branch. The original message and all of its descendants remain in the tree, so you can switch back with the same sibling controls. ## Data model Messages are persisted with a parent message ID. Root messages have no parent. The client uses `useThread` to project the selected path and to keep each active assistant response attached to its own reserved node. See [useThread](../threads) for the tree, cursor, active-path, and run model. ## Related - [Parallel Responses](./parallel-responses) - [Architecture](../core/architecture)