Epic Plan

Epic Plan Skill

A user invocation (/epic-plan <objective>) forks the epic-planner agent with this procedure in context. The epic objective (or an existing epic-manifest path) for this run is:

$ARGUMENTS

This skill frames work for the epic-planner agent, parallel to how .claude/skills/epic-orchestrate/SKILL.md frames work for epic-orchestrator. It documents the epic-worthiness gate, decomposition and wave design, per-feature complexity assessment, the preparation-mode child delegation contract, integration-branch fan-in, the kickoff-prompt artifact, and planning-checkpoint handling so the procedure is not re-derived ad hoc on each planning run. Planning ends at preflight clearance; no atomic execution, PR authoring, or CI monitoring occurs under this skill.

Prerequisites

Before proceeding, epic-planner must:

1. Read CLAUDE.md for repository tone policy and architectural context.
2. Read applicable .claude/rules/ files for the languages in scope.
3. Read the policy files listed in the compliance reading order section of CLAUDE.md.

Epic-Worthiness Gate

The first planning step is a deterministic assessment of whether the objective warrants an epic:

• Decompose the objective into candidate child features, each independently mergeable with its own issue, feature folder, and PR.
• The objective warrants an epic only when BOTH hold:
  1. The decomposition yields two or more child features, and
  2. At least one candidate feature exceeds — or the combined scope clearly exceeds — a single large-path feature's practical change budget.

When the gate fails, epic-planner reports to the user that the complexity does not warrant an epic, states the rationale (feature count and estimated change budget), and offers to delegate the work directly to a single Agent(orchestrator) run as one feature. It records the verdict under epic_worthiness in the planning checkpoint and proceeds with epic scaffolding only when the gate passes or the user explicitly directs it to.

Decomposition and Wave Design

For an epic-worthy objective:

1. Define the epic slug and epic home docs/features/epics/<epic-slug>/.
2. Author docs/features/epics/<epic-slug>/epic.md using the manifest frontmatter schema defined in the epic-orchestrate skill (that skill is the single schema authority; do not redefine it here). The Markdown body carries the epic narrative: goal, scope, non-goals, shared design, and decomposition rationale.
3. Derive depends_on edges from real upstream/downstream contracts only; do not add ordering edges for stylistic reasons, because every edge reduces execution parallelism.
4. Compute wave assignment with the longest-path layering formula from the epic-orchestrate skill (scripts/dev_tools/epic_wave_computation.py is the tested reference implementation) and reject cycles or unresolved references before any preparation is delegated.
5. Record the planned waves in the planning checkpoint and in the epic narrative.

At manifest-authoring time child issues do not exist yet, so issue_num values are recorded as placeholders and back-filled from each child's promotion receipt as preparation completes. The manifest is committed in final, resolved form before the kickoff artifact is written.

Complexity Assessment

Assess each child feature's complexity band (C1-C4) using the model_policy scale and signals in config/orchestration-routing.json, and record the band with a short rationale in the planning checkpoint's features[] entries and in the epic narrative. The bands serve two purposes: they feed the epic-worthiness rationale, and they give each child orchestrator's own model-selection step a reviewed starting assessment.

Integration Branch Lifecycle

1. Before any preparation delegation, create the integration branch off the tip of main if it does not already exist: git fetch origin main, git checkout -b epic/<epic-slug>-integration origin/main, git push -u origin epic/<epic-slug>-integration.
2. Commit the epic home (epic.md) to the integration branch before delegating preparation.
3. All prepared child outputs fan in to the integration branch (see Fan-In below), so the branch's final state is the complete, execution-ready epic plan.

Preparation-Mode Child Delegation

Delegate one Agent(orchestrator) run per child feature. Because preparation produces documents and plans rather than code, dependency edges impose no build-order constraint: launch ALL child preparations concurrently (one message, N Agent calls, each isolation: "worktree" and run_in_background: true), branching each worktree from origin/epic/<epic-slug>-integration. For a dependent feature, include the upstream features' planned scope (spec/plan references or manifest excerpts) as context lines so its spec and plan cite the upstream contracts they will consume.

Each delegation prompt includes the literal preparation-mode kickoff line:

Preparation mode: true. route_id: preparation. epic_feature_folder: <epic-slug>. integration_branch: epic/<epic-slug>-integration. Perform promotion, research, feature documents (spec.md, user-story.md), atomic planning, and preflight clearance only. Atomic execution, PR authoring, and CI monitoring are out of scope for this run and are executed later by epic-orchestrator. After the atomic-executor preflight returns PREFLIGHT: ALL CLEAR, commit the feature folder and plan to the current branch, set out-of-scope step statuses to not-applicable, set next_step to S5_atomic_execution, and stop, reporting the plan-path and preflight status.

The prompt must also reference the child's target feature folder path once promotion assigns it, or the promotion inputs (potential entry path, short name) when it does not exist yet. The preparation-mode kickoff line deliberately omits the epic-mode marker (Epic mode: true) so the enforce-epic-wave-barrier.ps1 deterrent, which gates execution-phase delegations, does not apply to preparation.

Child run contract (route_id: preparation)

A preparation-mode orchestrator run:

• Selects route_id: preparation (defined in config/orchestration-routing.json), whose required receipts are task-researcher, prd-feature, atomic-planner, and atomic-executor (preflight-only), the skills orchestrate, feature-promotion-lifecycle, and atomic-plan-contract, and the promotion plus validator MCP tools.
• Runs promotion via the MCP surface, research, feature documents, atomic planning, and the atomic-executor preflight (precondition validation only, per the orchestrate skill's R2 semantics), iterating plan revisions until PREFLIGHT: ALL CLEAR.
• Terminates with completed_steps containing S3_promotion and S4_atomic_planning, next_step: "S5_atomic_execution", out-of-scope step statuses not-applicable, and blocked_reason: "none". The route's requires_ci_gate: false means the completion validator demands no ci_gate/pr_gate evidence; the run must NOT assert next_step: "complete".

Fan-In to the Integration Branch

As each child preparation completes:

1. Fetch the child worktree's branch and merge it into epic/<epic-slug>-integration. Prepared outputs live in disjoint docs/features/active/<feature>/ trees, so conflicts indicate a decomposition defect; on conflict, halt fan-in and record blocked state rather than resolving ad hoc.
2. Back-fill the child's issue_num (and resolved feature_folder) into the epic manifest.
3. Update the planning checkpoint's features[] entry (preparation_status, plan_path, preflight_status).
4. Remove the child worktree once its branch is merged.

After the final fan-in, push the integration branch.

Kickoff Prompt Artifact

After all features are prepared and committed, write the epic-orchestrator kickoff prompt to artifacts/orchestration/epic-kickoff-<epic-slug>.md, and commit a durable copy to docs/features/epics/<epic-slug>/epic-kickoff.md (the artifacts/ tree is gitignored; the committed copy travels with the integration branch). The artifact contains:

# Epic Kickoff: <epic-slug>

Planned by epic-planner on <iso8601>. All child features are prepared: issues promoted, active
folders created, research complete, spec/user-story written, atomic plans approved, preflight
ALL CLEAR. Planning state: artifacts/orchestration/epic-planner-state.json (branch:
epic/<epic-slug>-integration).

## Invocation Prompt

Run `/epic-run <epic-slug>` to execute this epic, or paste the prompt below.

Use the epic-orchestrator subagent to execute the prepared epic at
docs/features/epics/<epic-slug>/epic.md. The integration branch
epic/<epic-slug>-integration already contains every prepared feature folder and approved atomic
plan; child features resume at atomic execution from their committed plan-path rather than
re-planning. Execute per the epic-orchestrate skill: wave-scheduled child orchestrator runs in
isolated worktrees, merge-on-green fan-in to the integration branch, and the final
integration-to-main PR.

## Feature Summary

| issue_num | feature_folder | wave | complexity | plan-path |
| --- | --- | --- | --- | --- |
| ... | ... | ... | ... | ... |

The ## Invocation Prompt section is the exact text the user replays (from the main session, never from an orchestrator agent) to launch execution.

Checkpoint Handling

Persist artifacts/orchestration/epic-planner-state.json after every completed step with the fields listed in .claude/agents/epic-planner.md (## Checkpoint Persistence). On resume, re-derive durable ground truth from git branch/git worktree list --porcelain, the epic manifest, and the prepared feature folders; treat the checkpoint's next_step as the resume pointer, not as a substitute for on-disk state.

Completion Report

The final report to the user must include: the epic manifest path, one plan-path: line plus preflight status per feature, the integration branch name, and the kickoff artifact paths. End with the statement that execution has NOT started and will begin only when the user runs /epic-run <epic-slug> or replays the kickoff prompt.