/evanflow-writing-plans

name: evanflow-writing-plans
description: Turn a spec or requirements into a bite-sized implementation plan. File-structure-first (deep modules), embedded grill to stress-test, no forced sub-skill chains. Use when you have a spec or clear requirements and are ready to plan execution.

EvanFlow: Writing Plans

Vocabulary

See `evanflow` meta-skill. Key terms: **deep modules**, **interface**, **vertical slice**, **deletion test**.

When to Use

• A spec or clear requirements exist
• Multi-step task that benefits from upfront decomposition
• About to touch ≥3 files

**SKIP when:** single-file change, typo fix, one-line config tweak. Just do it.

The Flow

1. Scope Check

If the spec covers multiple independent subsystems, suggest splitting into separate plans. Each plan should produce working, testable software on its own.

2. File Structure First

Before any tasks, name the files that will be created or modified, with a one-line responsibility for each. This locks in decomposition decisions.

Example (adapt the paths to your project's structure):

<backend>/routers/foo.ts          — API router; thin, delegates to service
<backend>/services/foo.ts         — business logic; pure where possible
<backend>/services/foo.test.ts    — vertical-slice tests
<frontend>/pages/foo.tsx          — UI; consumes the API

Apply the **deletion test**: if a file would just shuffle complexity to its callers, fold it into the caller.

2.5. Parallelization Check (offer coder-overseer if applicable)

After the file structure is sketched, ask: **does this plan have 3+ truly independent units that share a common interface contract?**

If YES — offer `evanflow-coder-overseer` to the user as the execution path:

> "This plan has [N] independent units sharing [contract]. We could execute it sequentially via `evanflow-executing-plans`, or in parallel via `evanflow-coder-overseer` (one coder per unit + per-coder overseer + integration overseer + executable contract via integration tests). Parallel is faster for big plans and adds independent QA, but only works if the units are truly independent. Which?"

Signals that favor coder-overseer:

• 3+ files/modules that don't import each other
• A clear shared interface contract (types, naming, invariants)
• Integration touchpoints that can be expressed as named integration tests
• Plan would otherwise be tedious to execute serially

Signals that favor sequential `executing-plans`:

• Tasks have hidden dependencies (one's output feeds the next)
• Fewer than 3 units
• No shared contract surface — units don't need to interoperate
• Risk-averse work (auth, payments, migrations) where a single careful pass beats parallelism

If the user picks coder-overseer, structure the plan with a per-coder section and the cohesion contract upfront. If sequential, continue to step 3 normally.

3. Embedded Grill

Stress-test the structure before writing tasks:

• "Where does this go wrong if the user does X?"
• "What happens if this fails halfway? What's the recovery?"
• "Is there an existing service in the project that already does part of this?"
• "Does the file structure follow project conventions documented in CLAUDE.md or visible in similar existing files?"
• "Are we introducing or changing domain terms? Update `CONTEXT.md` first?"

4. Bite-Sized Tasks

Each task is one focused unit (~15-30 min of work). Within each task, list bite-sized steps (~2-5 min each):

### Task 1: [Component Name]

**Files:** Create `path/to/foo.ts`, modify `path/to/bar.ts:123-145`, test `path/to/foo.test.ts`

- [ ] Write the failing test (one behavior — see evanflow-tdd)
- [ ] Run test, confirm it fails for the right reason
- [ ] Write minimal implementation
- [ ] Run test, confirm it passes
- [ ] Run the project's quality checks (typecheck / lint / test) — exact commands are project-specific; see CLAUDE.md or the project's README

After all tasks complete, the executor hands off to `evanflow-iterate` for self-review, then **stops and reports**. The plan does NOT include staging or committing — the user controls those.

5. Plan Header (lighter than upstream)

# [Feature Name] Plan

**Goal:** [one sentence]
**Architecture:** [2-3 sentences]
**Files:** [list from step 2]

---

**No "REQUIRED SUB-SKILL" header.** Sub-skills are suggestions documented inline at hand-off points, not mandates baked into the plan format.

6. Save the Plan

Default location: `docs/plans/YYYY-MM-DD-<topic>.md`. If the user has a different preference, honor it. Don't write to any vendor-specific path unless explicitly asked.

Hard Rules

• **Never include staging or commit steps in the plan.** Plans end at "verified, await user direction." The user decides when to stage, commit, push, merge.
• **No forced sub-skill chain.** No "must use using-git-worktrees" or "must use subagent-driven-development" header.
• **Plans live where the user wants.** Default `docs/plans/` only if no preference stated.
• **TDD by default.** Every code task is structured as test-first. Exceptions (configs, schemas, prototypes) are flagged inline.

Hand-offs

• Plan written → `evanflow-executing-plans`
• Need to design an API surface first → `evanflow-design-interface`
• Architecture concerns surfaced → `evanflow-improve-architecture` first, then back here