sidequest

name	sidequest
description	Fork the current Claude Code session at this moment so divergent work can be picked up later in a separate session, without disturbing the trunk. One command, two behaviours auto-detected from the work-log folder: missing → create a new fork snapshot; exists → resume the saved one. Writes/reads work-log/<parent>/forks/<forkName>/session-1.md.

Sidequest

A sidequest is a checkpoint written at a fork point in the current Claude Code session. The current session (the parent / trunk) keeps going as if nothing happened. The sidequest file is a saved jumping-off point that a different future Claude Code session can pick up.

The router passes any text after sidequest as $ARGUMENTS. Use that to dispatch (see Step 0).

One command, two behaviours — dispatched automatically based on what's already on disk:

Situation	Mode
No forks/<forkName>/ folder anywhere under work-log/	Create
forks/<forkName>/ folder already exists	Resume
/mosaic-buddy sidequest (no args)	Ask the user

When users create sidequests

Two archetypal triggers — name them in §1 of the snapshot when they apply:

1. Second-order effect surfaced mid-work. The trunk is doing X; along the way the user noticed Y is worth doing but is tangential. They fork Y off so the trunk stays focused on X.
2. New opportunity built on the trunk's output. The trunk just produced something (a schema, an API, a doc) that enables a different direction the user wants to explore. They fork off the new direction without losing trunk momentum.

The user picks how to work the sidequest after it's created — same branch, fresh branch, or a separate worktree for physical isolation. The sidequest snapshot itself is just a saved jumping-off point. Don't presume an answer; record the starting state and let the resumer choose.

Step 0: Dispatch

Parse the input first.

• If $ARGUMENTS is empty → follow Step 0a (interactive mode select).
• Else, strip a leading new if present (backward-compat with 3.5.0 syntax — just treat it as the name). The remaining text is forkName.
• Normalise forkName against ^[a-z0-9][a-z0-9-]*$: lowercase, replace spaces/underscores with -, strip other chars. Confirm with the user if normalisation materially changed the input. Forbid the literal name new (it would be ambiguous with the strip rule).

Then dispatch by searching for the fork folder:

PROJECT_ROOT="$(git rev-parse --show-toplevel 2>/dev/null || pwd)"
MATCHES=$(find "$PROJECT_ROOT/work-log" -mindepth 3 -maxdepth 3 -type d \
  -name "$FORK_NAME" -path '*/forks/*' 2>/dev/null)

if [ -z "$MATCHES" ]; then
  MODE=create
else
  MODE=resume
fi
echo "Dispatched: MODE=$MODE"

Tell the user which mode you picked, in one short line — e.g. "No existing fork by that name — creating a new one." or "Found an existing fork — resuming it."

If multiple matches come back (same forkName under different parents), list the parents via AskUserQuestion and let the user pick which one to resume.

Step 0a: No args — ask the user

Ask via a single AskUserQuestion:

• Question: "Create a new sidequest, or resume an existing one?"
• Header: "Sidequest"
• Options:
  • "Create new" → ask follow-up for a kebab-case name (suggest 2–3 derived from the actual exploration the user just described, not generic placeholders), then enter CREATE mode
  • "Resume existing" → list current forks as the options (find "$PROJECT_ROOT/work-log" -mindepth 3 -maxdepth 3 -type d -path '*/forks/*'), then enter RESUME mode

---

CREATE mode

C1: Resolve the parent session name

The fork lives under the parent session's work-log folder, so we need the parent's name. This is the current Claude Code session's title.

SESSION_ID="$CLAUDE_CODE_SESSION_ID"
PROJECT_ROOT="$(git rev-parse --show-toplevel 2>/dev/null || pwd)"
PROJECT_SLUG="$(echo "$PROJECT_ROOT" | sed 's|/|-|g')"
SESSION_JSONL="$HOME/.claude/projects/$PROJECT_SLUG/$SESSION_ID.jsonl"

CURRENT_TITLE=$(grep -m1 '"type":"custom-title"' "$SESSION_JSONL" 2>/dev/null \
  | python3 -c 'import sys,json; print(json.loads(sys.stdin.read()).get("customTitle",""))' 2>/dev/null)

echo "Parent session title: ${CURRENT_TITLE:-<unnamed>}"

• If non-empty → PARENT = CURRENT_TITLE. Continue to C2.
• If empty → trunk is unnamed. Ask the user via a single AskUserQuestion:
  • Question: "This Claude Code session isn't named yet. What should we call the trunk so the sidequest can live under work-log/<trunk>/forks/<forkName>/?"
  • Header: "Trunk name"
  • Options (2–3): sensible kebab-case suggestions derived from the actual work this session has been doing (scan the transcript) — not generic placeholders. Always include a "Skip naming" option that falls back to unnamed-YYYY-MM-DD (current date).
  • Normalise the chosen name against ^[a-z0-9][a-z0-9-]*$ (lowercase, replace spaces/underscores with -, strip other chars). Set PARENT to the result and continue.

After resolving PARENT, tell the user to run /rename so the Claude Code session title matches the work-log folder (slash commands can't be invoked from inside a skill):

Run this now so the session title matches the sidequest's parent folder:

/rename <PARENT>

Proceed regardless of whether the user runs it — the fork file uses the resolved PARENT either way.

C2: Confirm there's no collision

Step 0's dispatcher already verified forks/<forkName>/ doesn't exist anywhere under work-log/. This step is a belt-and-braces re-check in case the user picked a name in Step 0a that happens to collide under the current parent:

FORK_DIR="$PROJECT_ROOT/work-log/$PARENT/forks/$FORK_NAME"
if [ -d "$FORK_DIR" ]; then
  echo "COLLISION"
  ls "$FORK_DIR"
fi

If $FORK_DIR already exists (rare — only possible if dispatch was via Step 0a):

• Do not overwrite. Stop.
• List the parent's existing sidequests (ls "$PROJECT_ROOT/work-log/$PARENT/forks/") so the user can pick a non-colliding name.
• Suggest a few alternative names derived from the user's described exploration.

Names only need to be unique within the same parent. The same forkName under a different parent is fine.

C3: Ensure work-log/ is gitignored

GITIGNORE="$PROJECT_ROOT/.gitignore"
if git -C "$PROJECT_ROOT" rev-parse --git-dir >/dev/null 2>&1; then
  if ! grep -Eq '^[[:space:]]*/?work-log/?[[:space:]]*$' "$GITIGNORE" 2>/dev/null; then
    [ -s "$GITIGNORE" ] && [ "$(tail -c1 "$GITIGNORE" 2>/dev/null)" != "" ] && printf '\n' >> "$GITIGNORE"
    printf '\n# Claude Code handoff/sidequest snapshots (local-only)\nwork-log/\n' >> "$GITIGNORE"
    echo "Added work-log/ to $GITIGNORE"
  fi
fi

mkdir -p "$FORK_DIR"
TARGET="$FORK_DIR/session-1.md"

If .gitignore was modified, mention it in the Step C6 report.

C4: Gather grounding facts (parallel)

Same as /mosaic-buddy handoff:

git status
git diff --stat
git log --oneline -20
git branch --show-current

Then scan the transcript for the three things that matter most to a sidequest:

• Divergence reason — why is the user forking here and not just continuing? This is the soul of the file.
• What the trunk is doing — so the resumed fork knows what it should NOT duplicate.
• What the fork is for — the specific spike / experiment / alternate approach being explored.

C5: Write the fork snapshot

Use this template. Be concrete — file paths, line numbers, exact commands. A future agent reading only this file should be able to act without re-deriving anything.

# Sidequest — <forkName>

**Parent session:** <PARENT>
**Forked at:** <YYYY-MM-DD HH:MM>
**Claude Code session id at fork:** <CLAUDE_CODE_SESSION_ID>
**Branch:** <branch>
**Working directory:** <project root>

---

## 1. Why this fork exists

<1–3 sentences. The user's reason for branching off here. Quote them when
possible. Without this, the resumer has no idea why the trunk wasn't enough.>

## 2. Trunk context (what the parent was doing at fork time)

<1–3 sentences summarising the parent's refined agenda at the moment of fork.
Do not restate the parent's full handoff — the resumer can read it directly
under work-log/<parent>/session-N.md. Just enough so the fork knows where it
diverged.>

## 3. Fork agenda (what THIS sidequest should accomplish)

<Specific. Bounded. "Try X without committing to it." "Spike Y on a throwaway
branch." "Explore alternative Z and report back.">

## 4. Starting state

**Files & symbols the fork should start from:**
- `path/to/file.ts:42-110` — <why it matters>

**Uncommitted state at fork time:**
```
<git status -s output>
```

**Useful commands:**
```bash
<actual commands, not placeholders>
```

## 5. Constraints / non-goals

<What this sidequest should NOT do. Scope boundaries. Anything the user
explicitly said is out of bounds for this exploration. If none, write "None.">

## 6. Open questions for the user

<Anything the resumer needs answered before work can continue. "None." if
nothing.>

## 7. Git state at fork

```
<paste output of `git status` and `git log --oneline -5`>
```

C6: Report

Tell the user in 2–3 lines:

• Path written: work-log/<parent>/forks/<forkName>/session-1.md
• One-sentence summary of the fork's purpose
• Resume command (run in a new Claude Code session): /mosaic-buddy sidequest <forkName> (no new keyword — the skill auto-detects)
• Reassurance: the trunk session (this one) continues unaffected.
• If .gitignore was modified in C3, mention it.

Do not offer to commit the file. The user decides when (and whether) to commit work-log/ entries.

---

RESUME mode

R1: Locate the fork

Step 0's dispatcher already found the fork(s). If multiple matches existed (same forkName under different parents), Step 0 disambiguated via AskUserQuestion. By this point you should have a single $FORK_DIR and $PARENT extracted from the path:

# $FORK_DIR should be set from Step 0's match
PARENT=$(basename "$(dirname "$(dirname "$FORK_DIR")")")

R2: Read the fork snapshot

• Always read the latest session-N.md in the fork dir in full. That's the active snapshot.
• If earlier session-*.md files exist (the fork itself has been handed off before), skim oldest → newest for: closed threads, decisions superseded, gotchas still relevant. Latest is the source of truth.
• Also Read the parent's latest session-N.md if it exists, but only for trunk context — the fork's own §1–§5 are authoritative.

Use the Read tool, not cat.

R3: Verify repo state

The fork was a snapshot in time. Confirm the world is still close:

git status
git log --oneline -10
git branch --show-current

Compare to the fork's "Git state at fork" section. Surface divergence before proposing next steps:

• Branch has changed
• Commits have been added or removed since the fork
• Files cited as key reading no longer exist or have moved
• Uncommitted state at fork is now committed (or gone)

If anything diverged materially, ask the user to confirm the sidequest is still the right starting point.

R4: Optionally suggest renaming this session

If $CLAUDE_CODE_SESSION_ID is set and the current session has no custom-title record in its jsonl, gently suggest:

Run /rename <forkName> to label this resumed session so further /mosaic-buddy handoff or /mosaic-buddy sidequest new calls keep this work under a consistent name.

Don't nag if the session is already named (the user may want a distinct label).

R5: Brief the user

Short, structured briefing (not the full file — they can read it themselves):

Resuming sidequest: <forkName>  (forked from <parent>, <date>)

Why this fork exists:
  <§1, 1–2 lines>

Fork agenda:
  <§3>

Constraints / non-goals:
  - <§5 bullets>

Starting state:
  - <key file/line from §4>

Repo state check:
  <"matches fork point" OR brief list of differences>

Open questions for you:
  <from §6 — only if non-empty>

End with: "Ready to take the sidequest. Want me to start, or somewhere else?"

---

Rules

1. Forks are snapshots. Resume mode never modifies the fork's session-1.md. If the resumed work later needs its own checkpoint, that's a regular /mosaic-buddy handoff (which writes session-2.md into the fork dir — fine, mirrors the handoff layout).
2. If the trunk is unnamed, ask (don't refuse). Use AskUserQuestion to resolve a parent name, then tell the user to run /rename so the session title matches.
3. Never overwrite an existing fork. Create mode aborts on collision and lists alternatives.
4. The trunk session is unaffected when creating a sidequest — no branches, no worktrees, no commits, no edits to the parent's work-log files. Just a new file under forks/.
5. Project-local only. Everything lives under <projectRoot>/work-log/. Never ~/.claude/ or sibling projects.
6. Don't auto-execute the fork's agenda on resume — report it, wait for the user's go-ahead.
7. Don't quote /compact — sidequest is independent of context compaction.
8. Don't write custom-title jsonl records directly — only the user, via /rename, should do that.