## Decision Desk forking Eli wants to explore another direction while keeping the original conversation available\. A fork is useful for that\. It separates conversation identity and future journal ownership\. It does not isolate workspace changes\. ### Milestone\: Fork the current conversation **Need\.** Keep the original Lantern Board discussion while creating another conversational starting point\. **Obstacle\.** The word “fork” can suggest a Git branch\, a file snapshot\, or a previous\-message picker\. The supplied `/fork` does none of those things\. Use the complete [Decision Desk recipe]() and its [state ledger]()\. Create a **new** disposable lab for this story\. Preserve the previous receipt separately if you still need it\. **Terminal shell — Decision Desk preparation\, from extracted `examples/`\:** ~~~sh bun return-desk/lab.ts '{"version":1,"op":"discover"}' RECEIPT=$(mktemp -t continuity-decision-receipt) bun return-desk/lab.ts '{"version":1,"op":"act","action":"create"}' | tee "$RECEIPT" ~~~ Stop on `ok: false`\. Then retain its paths and the intended executable\: **Terminal shell — read the successful Decision Desk receipt\:** ~~~sh LAB=$(jq -r '.root' "$RECEIPT") SOURCE=$(jq -r '.yesterday' "$RECEIPT") SESSIONS=$(jq -r '.sessions' "$RECEIPT") PROJECT=$(jq -r '.cwd' "$RECEIPT") OMP_BIN=$(command -v omp) ~~~ The same prerequisites and stop rules from [Return Desk lab setup]() apply\. Record the parent and workspace before opening OMP\: **Terminal shell — read\-only baseline\:** ~~~sh shasum -a 256 "$SOURCE" jq -s 'map(select(.type == "session") | {id,parentSession,cwd,title})' "$SOURCE" cat "$PROJECT/today.txt" jq -r '.commands.resumeExplicitPath' "$RECEIPT" ~~~ Run the complete printed resume command\. Stop if it requires model\/auth setup\. Do not submit a prompt\. Inside the idle fictional conversation\: **Human OMP slash command — create the conversational fork\:** ~~~text /fork ~~~ Then inspect the child\: **Human OMP slash commands — inside the fork\, one at a time\:** ~~~text /session info /dirs ~~~ Keep the child active for the reset sequence in the next chapter\. ### The fork ledger A successful interactive fork has these source\-backed effects\: | Field | Expected result | | --- | --- | | Persistent identity | A new journal ID\. | | Transcript path | A new JSONL path\. | | Parent metadata | `parentSession` records the previous persistent ID\. | | Title and cwd | Retained from the current session\. | | Live conversation | Retained\. | | Ordinary steering\/follow\-up queues | Retained by this fork path\. | | Journal entries | All existing non\-header entries are carried into the new journal—not only the currently visible messages\. | | Workspace files | Still the same files in the same workspace\. | | Session artifacts | Copied recursively where available\, best\-effort\. | For this public source\, the child’s parent ID should be\: `11111111-1111-4111-8111-111111111111` The current registry description mentions a fork “from a previous message\.” The implementation route is more specific\: `handleForkCommand` calls `AgentSession.fork()` immediately\. **This is a current\-state fork\, not a previous\-message picker\.** A copied journal can retain older branches and pre\-clear entries that are not in current model context\. Forking is therefore not a way to reduce the disclosure content of a later export\. ### Artifacts are not a verified backup `copySessionArtifacts` derives the artifact directory by removing `.jsonl` from the transcript filename\. - Missing sources are ignored\. - Other copy errors are logged rather than thrown from that helper\. - The fork can therefore exist without every expected artifact having copied\. That copy does not cover arbitrary workspace files\, remote copies\, previously generated exports elsewhere\, or a guaranteed complete backup of every dependency\. **Recorded checks\.** The real SDK\/registry\/controller fork check created a new identity with parent metadata\, retained messages and ordinary queues\, preserved parent bytes around the fork call\, and copied one ordinary artifact\. The same test then wrote a fictional file in the shared workspace and confirmed that the parent manager saw the changed file at the same cwd\. The write was a test action\, not something `/fork` performed\. A separate real `copySessionArtifacts` check encountered a regular file blocking the destination directory\. It returned without throwing and did not copy the artifact\. That supports the best\-effort warning\; it is not broad filesystem coverage\. **Failure and recovery\.** Interactive `/fork` refuses while streaming\. An in\-memory session cannot fork through this path\. A before\-switch hook can veto it\. After any refusal or error\, inspect the actual file and identity before proceeding\. **Self\-check\.** If Eli later changes a workspace file while working in the fork\, will resuming the parent undo that file change\? **Answer\:** No\. The conversation identities differ\; the workspace is shared\. ### Interactive and startup forks differ This is a source\-backed comparison\, not another executed scenario\: | Boundary | Interactive `/fork` | Startup `--fork` | | --- | --- | --- | | Source | Current session | Explicit path or resolved native identity | | Cwd | Existing active cwd | Launch cwd supplied to startup | | Conversation | Retains current live messages | Rebuilds from copied journal history | | Parent\-process queues | Ordinary queues remain on the active fork path | No parent\-process steering\/follow\-up queues are cloned | | Journal | New identity\; original retained | New identity\; source retained | | Artifacts | Best\-effort copy | Best\-effort copy by default | | Workspace isolation | None | None | Full forks may inherit a provider prompt\-cache identity\. That is separate from journal identity and from provider request identity\. Changing the startup model\, thinking\, prompt\, or tool shape can suppress automatic inheritance\; explicit provider\/cache overrides are separate controls\. You do not need to tune those controls for this workbook\. The important conclusion is simpler\: **a new journal is not proof of a cold provider cache\, and a fork is not `/fresh`\.** **Source anchors\:** `packages/coding-agent/src/slash-commands/builtin-session.ts` — `fork` entry\; `packages/coding-agent/src/modes/controllers/command-controller.ts` — `handleForkCommand`\; `packages/coding-agent/src/session/agent-session.ts` — `fork`\; `packages/coding-agent/src/session/session-manager.ts` — `fork`\, `forkFrom`\, `copySessionArtifacts`\; `packages/coding-agent/src/main.ts` — `createSessionManager`\, `buildSessionOptions`\.