Elaborate: Git Strategy

Elaborate: Git Strategy

Composable sub-skill for selecting the delivery strategy, source branch, and merge behavior for an intent. Used by single-stage and stage-elaborate mode sub-skills.

This sub-skill runs inline — it has access to AskUserQuestion and the full conversation context.

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Inputs (from calling context)

• INTENT_SLUG — the intent slug
• AUTONOMOUS_MODE — true or false
• UNITS — the list of units defined during elaboration (needed for hybrid strategy heuristics)

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Step 1: Resolve Default Branch

# Config is now read via MCP tools or settings file directly
REPO_ROOT=$(git worktree list --porcelain | head -1 | sed 's/^worktree //')
# Resolve default branch directly (no shell lib needed)
DEFAULT_BRANCH=$(git symbolic-ref refs/remotes/origin/HEAD 2>/dev/null | sed 's|refs/remotes/origin/||' || echo "main")

Use the resolved branch name (e.g. main, master, dev) to replace {DEFAULT_BRANCH} in the questions below.

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Step 2: Select Delivery Strategy

Autonomous mode: Default to intent strategy (change_strategy: intent, auto_merge: true) from the repo's default branch. No hybrid overrides. Do NOT ask. Skip to Output.

Interactive mode: Use AskUserQuestion:

Question 1: Delivery strategy

{
  "questions": [
    {
      "question": "How should completed units be delivered?",
      "header": "Delivery Strategy",
      "options": [
        {
          "label": "Build everything, then open one PR",
          "description": "Units merge into an intent branch as they complete. Dependent units start automatically once their dependencies are done. One final PR for the whole intent."
        },
        {
          "label": "Review each unit individually",
          "description": "Each unit opens its own PR. Dependent units wait until their dependencies are merged. Best when you want to validate each piece before moving on."
        },
        {
          "label": "Build everything on {DEFAULT_BRANCH}",
          "description": "Same as above, but all work happens directly on {DEFAULT_BRANCH}. No feature branches, no PR — relies on CI to gate quality."
        }
      ],
      "multiSelect": false
    }
  ]
}

Question 2: Source branch (asked for ALL strategies)

{
  "questions": [
    {
      "question": "Which branch should units be created from?",
      "header": "Source Branch",
      "options": [
        {
          "label": "Use {DEFAULT_BRANCH} (recommended)",
          "description": "Create unit/intent branches from {DEFAULT_BRANCH}."
        },
        {
          "label": "Use my current branch",
          "description": "Create branches from the branch you're currently on."
        }
      ],
      "multiSelect": false
    }
  ]
}

Auto-merge is implicit based on strategy — do NOT ask the user:

• intent strategy → auto_merge: true (units auto-merge into the intent branch)
• unit strategy → no auto_merge key (user merges their own PRs)
• trunk strategy → no auto_merge key (no branches to merge)

Map user selections to config values:

What You Want	Strategy Value
Build everything, then open one PR	intent
Review each unit individually	unit
Build everything on {DEFAULT_BRANCH}	trunk

• "Build everything, then open one PR" → intent + auto_merge: true
• "Review each unit individually" → unit (no auto_merge key)
• "Build everything on {DEFAULT_BRANCH}" → trunk (no auto_merge key)

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Step 3: Hybrid Per-Unit Strategy (Auto-Decided)

Skip entirely if the user selected "Review each unit individually" or "Build everything on {DEFAULT_BRANCH}" — per-unit overrides only make sense with the intent branch strategy.

If the user selected "Build everything, then open one PR" (intent strategy), evaluate whether any foundational units should use per-unit branching instead. This creates a hybrid strategy where one or more units get their own PR (merged directly to the default branch), while the remaining units merge into the intent branch.

Auto-decide using these heuristics:

• If a unit has depends_on: [] (no dependencies) AND other units depend on it AND it involves schema migrations, shared library setup, or infrastructure provisioning → set git: { change_strategy: unit } on that unit (it should land on the default branch first)
• If the dependency graph is linear (A → B → C) with no clear foundational boundary → keep all units on the intent branch (no hybrid)
• If a unit has discipline: infrastructure and is depended on by feature units → set it as per-unit

Only ask the user via AskUserQuestion when the heuristic is ambiguous — e.g., multiple units could qualify as foundational but it's unclear which ones genuinely need to land on the default branch first. In that case:

{
  "questions": [{
    "question": "Multiple units could be delivered individually to {DEFAULT_BRANCH} before the rest. Which foundational units should get their own PR?",
    "header": "Hybrid",
    "options": [
      {"label": "None — all into intent branch", "description": "Standard intent strategy, no hybrid overrides"},
      {"label": "{unit-slug-1}", "description": "{one-line description}"},
      {"label": "{unit-slug-2}", "description": "{one-line description}"}
    ],
    "multiSelect": true
  }]
}

Units selected get git: { change_strategy: unit } in their frontmatter.

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Output

The git strategy configuration is carried forward to the calling mode sub-skill:

git:
  change_strategy: intent  # or unit, trunk
  auto_merge: true         # implicit for intent strategy; omit for unit/trunk
  auto_squash: false       # default false

Plus any per-unit overrides for hybrid strategy.