plan

cys:plan

Write an implementation plan a zero-context engineer could execute: bite-sized tasks, exact paths, complete code, TDD, frequent commits. The plan doubles as machine input — the parallel-plan-executor parses its task blocks into a dependency graph, so format discipline is load- bearing, not cosmetic.

Announce at start: "Using cys:plan to write the implementation plan."

Save plans to: docs/cys/plans/YYYY-MM-DD-<feature-name>.md (user preferences for location override this default).

Plan header

Every plan MUST start with:

# [Feature Name] Implementation Plan

> **For agentic workers:** execute this plan with the
> parallel-plan-executor Workflow (cys:run / the /cys:run-plan command).
> Steps use checkbox (`- [ ]`) syntax for tracking.

**Goal:** [one sentence]

**Architecture:** [2-3 sentences]

**Tech Stack:** [key technologies]

## Global Constraints

[Project-wide requirements, one line each, exact values copied
verbatim from the spec. Every task implicitly includes this section.]

---

Task format — the parser contract

### Task N: [Component Name]

**Files:**
- Create: `exact/path/to/file.js`
- Modify: `exact/path/to/existing.js`
- Test: `tests/exact/path/to/test.js`

**Interfaces:**
- Consumes: [backticked symbols from earlier tasks — exact signatures]
- Produces: [backticked symbols later tasks rely on]

Hard rules (the executor's parser depends on them):

• Task headers are exactly ### Task N: Title — sequential integer ids, never duplicated.
• Only backticked symbols count in Consumes/Produces; loose prose is ignored by the parser. Backtick every real interface (createWidget(), src/db.js); never backtick filler words.
• One entry per line in Consumes/Produces — a value wrapping onto a second line is silently lost by the parser.
• Consumes: None means an empty list; write it when a task is independent. Both the **Files:** and **Interfaces:** headers themselves must always be present, even for a task with an empty list — omitting either entirely (e.g. a typo like **Interface:** or **File:**) silently drops that task from the corresponding inference (symbol-based dependencies, or file-based serialization); the parser warns when a header is missing, but write the section explicitly rather than relying on that warning.
• Two tasks touching the same file are automatically serialized by the executor; design task boundaries so files are disjoint whenever possible — disjoint tasks run in parallel.