Design Memory

Design Memory — the .sumi/ contract

.sumi/ is what makes the commands compose. /style decides a visual direction once; /screen, /component, /page, /fix and a dozen others consume it instead of re-inventing a palette every invocation.

That only works if every command agrees on the file shape. Until v4.1.0 none was written down, and four commands wrote .sumi/style.json in four different shapes while other commands read whichever they assumed. This skill is the single definition.

Constants

The canonical .sumi/style.json. Every writer emits this envelope; nobody invents keys.

{
  "$sumi": "1",
  "meta": {
    "generated": "ISO-8601 timestamp",
    "updatedBy": ["/style"],
    "sector": "fintech",
    "mood": "professional",
    "platform": "web"
  },
  "project": {
    "framework": "react | vue | svelte | vanilla | swiftui",
    "styling": "tailwind | css | styled-components | swiftui",
    "typescript": true
  },
  "tokens": {
    "$schema": "https://design-tokens.github.io/community-group/format/",
    "color": {},
    "typography": {},
    "space": {},
    "radius": {},
    "shadow": {},
    "duration": {},
    "easing": {},
    "z": {},
    "$themes": { "light": {}, "dark": {} }
  },
  "tone": {
    "formality": "",
    "traits": [],
    "wordsToUse": [],
    "wordsToAvoid": []
  },
  "references": [
    { "app": "", "platform": "", "stealThis": "", "takeaway": "" }
  ]
}

Everything under tokens is W3C DTCG. Everything outside it is Sumi's own envelope, because DTCG has no way to express a sector, a tone of voice, or a list of reference apps.

The file set

Ownership

A writer touches its own subtree and nothing else. This is what allows four commands to share one file without clobbering each other.

Read order

Broad to specific. Later files override earlier ones where they overlap.

1. brief.json — who it is for and what problem it solves
2. map.json — what screens exist
3. style.json — what it looks like
4. vision.json — the visual bar and DNA match
5. wireframe-<screen>.json — the layout of the screen actually in play
6. decisions.log — the running override log; the last entry wins

Merge rules

1. Read-modify-write, never replace. Load the file, deep-merge your subtree, write it back. Append your command name to meta.updatedBy and refresh meta.generated. A whole-file replacement destroys three other commands' work and is the specific bug this contract exists to prevent.
2. Precedence: explicit user instruction > design memory > defaults. An instruction in the current turn wins immediately and appends to decisions.log with its reason.
3. Absent is not empty. No file means "not decided yet" — generate a value and offer to persist it. A file present but partial means "decided" for the sections that exist; fill only the gaps.
4. Never invent a token when style.json exists. If the palette is on disk, use it. Inventing a second palette mid-session is the most visible way to break the illusion that the commands are one system.
5. Conflict: ask once. If your write would change a value another command set in a previous session, surface both values in one line and ask. Do not ask twice in a session, and do not silently overwrite.

Routing

For the full JSON Schema of every file, worked merge examples, and the migration note for pre-v4.1.0 files: read references/sumi-file-schemas.md.

Cross-References

• design-systems-architecture — the DTCG token tiers tokens serializes
• design-token-presets — vetted starting token sets to seed tokens from
• sumi-orchestrator — pipelines that span several commands, which is when design memory earns its keep