dsh-session-tree

Append-only, multi-branch conversation trees for DeepSeek-Harness — branch from any earlier prompt, clone a branch into a new session, and browse the whole lineage as one merged WebUI graph. Old history is never edited or deleted.

Four commands:

Command	What it does
/tree	Open the merged lineage graph: every non-subagent session and node; selecting a node moves the tree cursor
/fork	Branch from an earlier user prompt — the fork appears in the graph and as an inline menu under its source session
/clone	Duplicate the current conversation into an independent new session under the same project
/session	Print the current session's tree status and surface mode

Screenshots

Tree panel (light and dark) with the sidebar's inline fork-branch menu:

The inline /fork branch menu beneath its source session:

Published as four npm packages under the @robiteame scope:

Package	Role
@robiteame/dsh-session-tree	Carrier Bundle: one install mounts everything below through its composition layer
@robiteame/dsh-pi-agent-session-tree	Host domain service: the SessionTree/SessionTreeStore domain model and the sessionTree Remote
@robiteame/dsh-tool-session-tree	Agent surface: the session_tree tool and the /tree /fork /clone /session commands
@robiteame/dsh-client-ui-session-tree	WebUI tree panel: a native tab in the Harness 0.2 right Sidebar, with an additive overlay fallback for older official builds

Install (users)

Desktop: Settings → Plugins → Add plugin, choose the official npm registry, install @robiteame/dsh-session-tree@0.7.4, then restart. CLI (0.2.1-rc.3 or newer):

dsh plugin --profile <profile> add @robiteame/dsh-session-tree@0.7.4

Requires DeepSeek-Harness 0.2.x and Node.js 22+, with no install scripts. Full steps, the mainland mirror that only serves 0.7.0, verification, and uninstall: INSTALL.md.

Edit the latest prompt

In the browser or desktop app, choose Edit beside Copy on the latest user message. The host cancels the current run and its running subagents before opening the editor, and parks queued input. Edit the text and choose Resend (or press Ctrl/Cmd+Enter). The corrected turn starts in a child session with the preceding history and original attachments. The original prompt and its replies remain available in the session tree; the corrected turn does not include them in its model context.

Canceling the editor leaves the source stopped. Other sessions and the ordinary composer draft are unaffected. If another client advances the source while the editor is open, reopen the editor before resending. For a newer prompt that is still queued, use the native queue's edit action; the plugin reports that case instead of changing an earlier prompt.

Commands

/tree — open the tree panel

/tree opens the right-side panel as one merged graph for the current session's lineage: ancestors, forks, and clones appear in a single git-style view, with user messages, assistant replies, tool calls, and model switches shown as connected nodes. Shared copied prefixes are deduplicated, fork points carry session badges, and the current session's path stays highlighted. Selecting a node moves the tree cursor; selecting a node owned by another session opens that session first. Collapse individual subtrees or whole session branches to focus the graph.

/fork — branch from a user prompt

/fork picks an earlier user prompt and grows a new branch from there: the conversation continues along the new path while the original one stays intact. The new session opens with that prompt ready to edit and keeps the completed turns before it. Selecting the first prompt starts with an empty history. The child keeps its parent session link. The plugin adds the new branch to the merged graph and also renders it as an inline collapsible menu directly beneath its source session's row. Both views follow the official reactive session list, so new branches appear without a refresh.

Remove a fork from the session list

Click the trash button on the right of an inline fork row to remove it from the session list. This uses Harness's native archiving: history is retained and the session can be restored through the host's archived-session controls. Child forks remain visible under the nearest unarchived ancestor, and restoring the parent restores their original nesting. Failed removals show an error and can be retried. Hosts without native archiving omit the button.

/clone — duplicate into a new session

/clone copies the current conversation — through its root path — into an independent Session under the same project. The source history stays read-only; the clone is yours to continue separately.

/session — inspect the current tree

/session prints the current session's tree status: node, message, and branch counts, the cursor and active branch, token usage, and the surface mode (native or projection).

Branch switching and graceful degradation

The plugin never modifies Harness core files. It capability-detects the optional branch-selection engine API at runtime:

• Native mode — on a checkout carrying dev/session-branch-surface.patch (Session.selectMessageSurface()), jumping switches the model-visible history directly: the next turn starts from the selected node.
• Projection mode — on official Harness builds, clicking a node moves the tree cursor and leaves the conversation history intact. Use /fork to continue from an earlier user prompt in a new session. The tree cursor and branches are saved under $DSH_HOME/storages/session-tree/.

Move the raw session.jsonl.zstd between machines together with the matching sidecar file to retain the tree state.

How it works

• Append-only — every node is immutable; branching and jumping only move the cursor. Old branches are never edited or deleted.
• Every entry is a node — messages, tool calls, model switches, compaction records, and branch summaries all become typed nodes; each has a unique nodeId and a parentId (root is null). A node may have multiple children — that is the fork.
• Cursor navigation — jumping moves the active leaf to a historical node; the next append grows a new branch from there. Sibling branches stay intact.
• LLM context — the selected path becomes model history in native mode or in a new session created by /fork.

Development (contributors)

The repository is a pnpm workspace building the three implementation packages standalone (no Harness checkout needed):

pnpm install
pnpm verify      # build + typecheck (host & client) + pack dry-run + vitest
pnpm pack:all    # produce the four tarballs

Tests use vitest from the repository root against the published Harness packages (0.2.1-rc.5). Earlier releases were also verified against 0.2.1-rc.2 and 0.2.1-rc.3. The browser spec in packages/client/ui-session-tree exercises both the 0.2 native right-Sidebar registration and the older overlay fallback.

Source integration against a Harness checkout

For debugging against the dsh-v0.2.1-rc.2 Harness source tag (native branch switching and source integration):

dev/install.sh /path/to/deepseek-harness     # applies both dev patches + copies packages
cd /path/to/deepseek-harness && pnpm install && pnpm run build

See dev/README.md for what each patch does. This flow is for contributors only; the source patches have not been validated against 0.2.1-rc.5. User installs never touch a Harness checkout.

License

MIT.