# Sus Change Plan

> Plan structural change while preserving behavior. Use when a refactor, rewrite, migration, upgrade, performance change, schema change, or wide architecture cleanup needs a proven baseline and staged transformation. Do not use for direct implementation, net-new feature design, or a single-seam lock-and-write.

- Skill: `jcosta33/sus-change-plan` (Agent Skill)
- Install (CLI): `npx skillmds@latest add jcosta33/sus-change-plan`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jcosta33/sus-change-plan/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: jcosta33 (https://skillmd.com/u/jcosta33)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/jcosta33/sus-change-plan

---


# Sus Change Plan

Unproven preservation is accidental destruction.

Ask required questions through the native picker, or numbered choices plus `Other`. Put the
recommendation first; offer three genuine options, two if binary; give each one plain reason and
cost.

## Method

Enter on explicit plan request or after the human selects a Suspec change-plan workflow.

Read project rules, durable decisions, current source, tests, and current-state maps. When wide change
lacks a proven map, map the unfamiliar or change-critical area as durable current state before
planning. Skip only when the change is isolated, the current map is proven, and no
behavior-preservation, staged-cutover, or rollback risk exists.

Resolve reversible conventions. Force material ambiguity into explicit human selection when it
concerns behavior, public contracts, security, cost, authority, or irreversible action. Block
dependent waves until selection.

## Artifact

Resolve `~/.agents/artifacts/<workspace>/` to an absolute path; derive `<workspace>` from the
repository or working-directory basename. Write there with `type: change-plan`, a unique `CHANGE-`
ID, and linked sidecars beside it. On collision or ambiguous workspace, present human-readable name
choices. On a blocked write, offer grant and retry, another agent-neutral user directory, or cancel.
Never overwrite or fall back to a repository, vendor directory, or temporary path.

Write local source references relative to the artifact. Use absolute paths only for runtime handoff.

### Shape

Use this minimal frontmatter shape:

```yaml
---
type: change-plan
id: CHANGE-{{slug}}
kind: refactor
preserves:
  - SPEC-feature#AC-001
  - PG-001
---
```

`preserves` is always a list. Use the full `SPEC-id#AC-NNN` for a governing requirement and
`PG-NNN` for a plan-local guarantee.

Write only load-bearing sections:

1. **Baseline:** current state, direct evidence, maps used.
2. **Target:** final structure, deliberate behavior changes, preserved behavior.
3. **Preservation guarantees:** `ID | Behavior | Verify with`.
4. **Transformation waves:** smallest ordered changes that leave build and tests green; each
   names affected surfaces, verification, and rollback point.
5. **Cutover / rollback:** observable entry, completion, abort, and restoration conditions.
6. **Task split:** dispatchable ownership and dependencies, or `None`.

Use frontmatter `kind` to name the transformation. Reuse full governing requirement refs under
`preserves`; mint plan-local `PG-NNN` only for preserved behavior with no requirement ID.

## Verify

- Demand golden, differential, or property checks that fail on drift. A green suite proves only its
  executed coverage.
- Give every compatibility shim a path, forward target, and mechanical removal condition.
- Count old call sites across source, tests, generated code, dynamic
  dispatch, registries, configuration, and reflection; completion targets zero outside named shims.
- Record every deliberate rewrite delta. Preserve everything else.
- Use one performance protocol before and after: workload, inputs, environment, warmup,
  samples, statistic, target, and regression ceilings.
- Use schema coexistence only when consumers cannot cut over atomically.

Verify the frontmatter and required sections, resolve every `preserves` ID against the source spec or
plan guarantees, and require each transformation wave to name verification.

## Output

Before handoff, cut repetition, softness, ceremony, and structural bloat without changing contracts,
identifiers, verbatim source text, evidence, or behavior. Rerun applicable checks. Return only
clickable Markdown links for the change plan and every sidecar, with compact `~/.agents/...` labels
and fully expanded absolute destinations. Explain only a blocker, failed creation, incomplete
verification, or irreversible-action confirmation.

## Close

Once fully actioned and no downstream step needs it, require one human disposition for the artifact
and its sidecars: Delete, Leave, or Promote. Promote moves transient material into project-owned
permanence. Delete every selected path and verify absence; survivors block close.