open-sprint

name	open-sprint
description	Open a new sprint by pulling WPs from BACKLOG into TASKS.md § Current, with BACKLOG removal enforced in the same phase. TRIGGER when user runs /open-sprint or asks to "open a sprint" / "start sprint N" / "pull items from backlog into a sprint". DO NOT TRIGGER mid-sprint, or on routine edits, or on wrap-up. Side-effecting on TASKS.md + BACKLOG.md, always proposes scope before applying.
argument-hint	[optional sprint number; defaults to next]
allowed-tools	Read, Write, Edit, Bash, Glob, Grep
disable-model-invocation	true

Open Sprint

Pull 3-6 WPs from BACKLOG.md into TASKS.md § Current, atomically removing them from the backlog.

Preconditions

Abort with a clear message if any of these fail:

• TASKS.md exists and has a ## Current: section header
• ## Current: is empty (no unchecked [ ] items under it). If open WPs remain → abort: "Current sprint has open items. Finish them or run /wrap-sprint first."
• BACKLOG.md exists and contains at least one WP (checkable lines matching ^- \*\*<ID>\*\* or similar)
• Working tree is clean (git status --porcelain empty except untracked artifacts). Wrap-up of prior sprint must have landed. "Commit or stash in-flight changes first; open-sprint will propose atomic edits across TASKS.md + BACKLOG.md."

Phase 1: Research

No edits. Build full context.

1. Read TASKS.md tail. Confirm the last sprint closed (session log entry present, Current empty). Note the next sprint number = last completed + 1.
2. Read BACKLOG.md in full. Enumerate open WPs grouped by section (A/C/F/G/H/I/J etc.). For each, note: ID, size (S/M/L), dependency arrows (← X / → Y), one-line intent.
3. Read CLAUDE.md § Hackathon Mission (if present) and the most recent memory via memory_search for hackathon deadline + judging weights. Confirm time remaining + ROI framing.
4. Scan recent git log (git log --oneline -10) to confirm the last sprint's commits are pushed and no uncommitted doc drift remains.
5. Check .claude/rules/*.md for any active guardrails relevant to the WPs you'll propose.

Done when: you can answer in one paragraph: what's open in BACKLOG, what's the next sprint number, and how much time remains to ship.

Phase 2: Propose sprint scope

Print a structured proposal to the user. Be terse.

Required elements:

• Sprint theme (one line, the "why of this sprint")
• 3-6 candidate WPs from BACKLOG, ranked by ROI against judging weights (Impact 30 / Demo 25 / Opus 4.7 Use 25 / Depth 20 for this repo). Size each (S/M/L).
• Dependencies resolved, if a proposed WP has ← X on an open BACKLOG item, either include X in this sprint or note why the dep is acceptable.
• Lane assignment, subagent lanes A/B/C vs main thread. Parallel where possible.
• Explicit cut list, what you're NOT pulling this sprint and why (brief).

Example proposal shape:

## Sprint N proposal, [theme]

Time check: [X hrs until build cutoff]. Judging-weight framing: [brief].

### Pulling (4 WPs)
1. I.5 (M) Managed Agents wrap, $5K side prize
2. G.7 (M) Per-server detail, judges can copy MCP config
3. J.2 (M) E2E Vercel verification
4. Playground UI validation through tunnel (from Sat deliverables)

### Not pulling (why)
- I.6 (L) Refine with Opus, chains after I.5, defer one sprint
- G.3 (L) Route designer, routes already work seeded; post-hackathon

### Lanes
- Main: I.5 (strategic)
- Subagent A: G.7
- Subagent B: J.2
- Subagent C: Playground validation

Reply with: `approved` | `1,3` (numbers to pull) | `cancel` | inline edits.

Wait for user approval. Silence is not approval. Auto mode is not blanket approval for scope.

Done when: user replies with an explicit set of WPs.

Phase 3: Execute atomically

Critical phase. Both files must be touched in the same logical step. Do NOT commit between TASKS.md edit and BACKLOG.md edit, they land together or not at all.

For each approved WP:

1. Add to TASKS.md § Current, unchecked bullet with size, ID, one-line intent, lane tag.
2. Remove from BACKLOG.md, delete the WP line entirely.

Order doesn't matter within the phase; what matters is that BOTH edits are complete before the phase ends.

Insert pattern for TASKS.md:

## Current: Sprint N, [theme] ([date])

[One-paragraph why, what judging signal / demo beat / dev friction this sprint buys]

- [ ] **N.1** (S|M|L) [intent]. (Main thread. | Subagent lane A.)
- [ ] **N.2** ...

Replace the entire existing ## Current: line (and anything between it and the next ##) with the new block.

Deletion pattern for BACKLOG.md:

Locate each pulled WP line via its ID (e.g. - **I.5** (M, P1 stretch)...) and delete the whole line. Do NOT leave empty section headers, if removing the last item under a heading empties the section, remove the heading too, or leave a placeholder: _(all pulled or shipped)_ to keep the structure visible.

Invariant enforcement: after both edits land, run a sanity grep:

for id in <pulled-ids>; do
  count=$(grep -c "\*\*${id}\*\*" BACKLOG.md)
  if [ "$count" -gt 0 ]; then
    echo "VIOLATION: ${id} still present in BACKLOG.md"
    exit 1
  fi
done

If any pulled ID is still in BACKLOG after Phase 3, stop and fix before proceeding to Phase 4. Do not leave the repo in an inconsistent state.

Done when: TASKS Current block is populated, BACKLOG has the pulled WPs removed, and the grep invariant passes.

Phase 4: Verify

1. git status --porcelain, show the user exactly which files changed. Expect TASKS.md + BACKLOG.md, nothing else.
2. git diff TASKS.md BACKLOG.md | head -60, print the delta so the user sees the atomic shape.
3. Remind the user:
   • Sprint is opened but NOT committed. They decide when to commit.
   • The pre-commit hook sprint-open-check.sh will warn if TASKS.md stages a new ## Current: block without BACKLOG.md deletions, a backstop for cases where this skill wasn't invoked.
4. Suggested next step: "Approve scope and I kick off WP plans per the Plan First rule in CLAUDE.md."

Done when: user sees a clean tree + atomic diff + knows the next action.

Edge cases

• User wants to add net-new WPs not in BACKLOG. Fine, add them to TASKS Current, but note that they bypassed the scoping rule. Don't touch BACKLOG for these. The hook will still warn on commit because BACKLOG has no deletions; the user can acknowledge and push through (warn, not block).
• User pulls a WP with an unlanded dep. Surface the dep in the proposal. Either include it or get explicit waiver.
• Mid-sprint "add one more WP". Open-sprint is for the initial scope. Mid-sprint additions happen in place (edit TASKS.md + remove from BACKLOG). The skill isn't needed for single-WP additions; the hook catches the hygiene.
• Sprint cancelled mid-flight. Return remaining open WPs to BACKLOG.md with updated notes, then run this skill cleanly for the next sprint.

Non-goals

• Not running /wrap-sprint, that's the sister skill for closing.
• Not planning individual WP implementation, that's the Plan First rule in CLAUDE.md (per-WP plan check-in before any Write/Edit).
• Not writing code, this skill only touches TASKS.md and BACKLOG.md.
• Not a replacement for human judgment on scope, the skill asks for explicit approval of the proposal before executing.