diff --git a/packages/docs/development/kiwi-package-plan.md b/packages/docs/development/kiwi-package-plan.md
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@@ -0,0 +1,144 @@
+# `@open-pencil/kiwi` extraction plan
+
+`@open-pencil/kiwi` should be the first file-format package split after `@open-pencil/dom-css`. The first migration must keep `.fig` import/export behavior inside `@open-pencil/core` while moving only scene-graph-agnostic Kiwi runtime code behind a standalone package boundary.
+
+## Scope boundary
+
+### Move first
+
+| Current path | Target path | Why it belongs in `@open-pencil/kiwi` | Preconditions |
+|---|---|---|---|
+| `packages/core/src/kiwi/schema-runtime/**` | `packages/kiwi/src/schema-runtime/**` | Pure Kiwi schema parsing, validation, binary encode/decode, byte-buffer utilities. Imports only local runtime modules. | Add package-local schema runtime tests and dist smoke. |
+| `packages/core/src/kiwi/fig/codec/schema/fig.kiwi` | `packages/kiwi/src/fig/schema/fig.kiwi` | Static Figma Kiwi schema text. It is data, not SceneGraph policy. | Keep raw-md bundler support in the new package build. |
+| `packages/core/src/kiwi/fig/codec/schema/index.ts` | `packages/kiwi/src/fig/schema.ts` | Parses and validates the static schema. Currently only depends on schema runtime plus raw schema text. | Rewrite imports to package-local runtime paths. |
+| `packages/core/src/kiwi/fig/codec/protocol.ts` | `packages/kiwi/src/fig/protocol.ts` | Low-level Figma multiplayer/Kiwi container byte inspection. No SceneGraph dependency. | Add fixtures for message-type and compression detection. |
+| `packages/core/src/kiwi/fig/codec/variable-bindings.ts` | `packages/kiwi/src/fig/variable-bindings.ts` | Low-level variable binding binary encode/decode helper. It should not need SceneGraph. | Replace `#core/bytes/hex` / `#core/types` imports with local helpers/types. |
+| `packages/core/src/kiwi/fig/codec/index.ts` | `packages/kiwi/src/fig/codec.ts` | Encodes/decodes Figma Kiwi messages. Mostly schema/runtime/protocol logic. | Remove `#core/color` dependency or make color parsing caller-owned; replace core shared types with local exported structural types. |
+
+### Keep in `@open-pencil/core` for now
+
+| Current path | Reason it stays |
+|---|---|
+| `packages/core/src/kiwi/fig/import.ts` | Creates `SceneGraph`, imports variables/components/pages, applies OpenPencil source metadata. |
+| `packages/core/src/kiwi/fig/lazy-import.ts` | Stores lazy import context in `SceneGraph` weak maps. |
+| `packages/core/src/kiwi/fig/node-change/**` | Converts between Figma `NodeChange` records and OpenPencil `SceneNode`, text, vector, paint, font, and layout types. This is `.fig` policy, not raw Kiwi. |
+| `packages/core/src/kiwi/fig/instance-overrides/**` | Resolves Figma component/instance override semantics into `SceneGraph`. |
+| `packages/core/src/kiwi/fig/parse/**` | `parse/core.ts` can move later to `@open-pencil/fig`; `transfer.ts` and `worker.ts` serialize `SceneGraph`, so they stay until `.fig` package extraction. |
+| `packages/core/src/kiwi/fig/container/**` | `.fig`/Kiwi container framing policy. Move later with `@open-pencil/fig`, unless a pure byte-container helper is split out deliberately. |
+| `packages/core/src/kiwi/fig/file.ts` | Re-export of core `.fig` I/O. |
+| `packages/core/src/io/formats/fig/**` | App/CLI-facing `.fig` read/write policy and renderer-backed export behavior. |
+
+## Dependency blockers to remove before moving
+
+- `fig/codec/index.ts` imports `parseColor` from `#core/color` for convenience factories. Options:
+  - remove string color parsing from the low-level package, or
+  - accept a caller-supplied `parseColor` option, or
+  - move only structural encode/decode first and leave convenience constructors in core.
+- `fig/codec/index.ts` and `variable-bindings.ts` import `Color`, `GUID`, `Matrix`, and `Vector` from `#core/types`. The Kiwi package should define minimal structural types locally and let core adapt them.
+- `variable-bindings.ts` imports `hexToBytes` from `#core/bytes/hex`. Copy a tiny local helper or expose it from the Kiwi package; do not depend on core.
+- Raw `.kiwi` loading currently relies on the root raw markdown/schema tooling. The new package build must prove raw schema import works from `packages/kiwi` in build and smoke tests.
+
+## Initial package shape
+
+```text
+packages/kiwi/
+  package.json
+  tsconfig.json
+  tsconfig.test.json
+  tsdown.config.ts
+  scripts/smoke-dist.ts
+  src/
+    index.ts
+    schema-runtime/
+    fig/
+      codec.ts
+      protocol.ts
+      schema.ts
+      schema/fig.kiwi
+      variable-bindings.ts
+      types.ts
+  tests/
+    schema-runtime.test.ts
+    fig-schema.test.ts
+    fig-codec.test.ts
+    protocol.test.ts
+    variable-bindings.test.ts
+```
+
+Public exports should stay narrow at first:
+
+```json
+{
+  ".": "./dist/index.js",
+  "./schema-runtime": "./dist/schema-runtime/index.js",
+  "./fig": "./dist/fig/index.js"
+}
+```
+
+`@open-pencil/core/kiwi` should keep compatibility re-exports during the first migration so app, CLI, MCP, and external consumers do not need to change immediately.
+
+## Package-local test plan
+
+Add these tests in `packages/kiwi/tests/**` before moving production callers:
+
+1. **Schema runtime smoke**
+   - Parse a small inline Kiwi schema.
+   - Validate field numbers and enum values.
+   - Compile it, encode a message, decode it back.
+
+2. **Bundled Figma schema guard**
+   - Validate the bundled `fig.kiwi` schema.
+   - Assert stable high-value facts already covered in `tests/engine/kiwi/schema-runtime.test.ts`:
+     - definition count is `605`
+     - `NodeChange` exists
+     - `InteractiveSlideElementChange` exists
+     - `Paint.colorVar` field number is `21`
+     - `NodeChange.pageType` field number is `397`
+     - `VariableField.OVERRIDDEN_SYMBOL_ID` enum value is `37`
+
+3. **Protocol helpers**
+   - `isZstdCompressed()` returns true for Zstd magic bytes and false for Kiwi payload bytes.
+   - `getKiwiMessageType()` reads a message type from a minimal encoded payload.
+   - Malformed payloads fail predictably without throwing unexpected internal errors.
+
+4. **Variable binding binary helpers**
+   - Varint encode/decode round-trips representative values: `0`, `1`, `127`, `128`, `255`, `16384`.
+   - GUID hex/byte conversion round-trips a known Figma GUID.
+   - Color variable binding encode output stays byte-stable for a known fixture.
+
+5. **Figma message codec**
+   - `initCodec()` is idempotent.
+   - `getSchemaBytes()` returns non-empty stable schema bytes.
+   - A minimal `FigmaMessage` encode/decode round-trips.
+   - A `NodeChange` with variable bindings uses the custom node-change path and decodes back to equivalent data.
+
+6. **Dist smoke**
+   - Import `@open-pencil/kiwi` built output from `dist`.
+   - Validate schema, initialize codec, encode/decode one minimal message.
+   - Assert no import of `@open-pencil/core` is required by the package dist.
+
+Repo-level tests under `tests/engine/io/fig/**`, `tests/engine/kiwi/serialize-fixes/**`, and Figma oracle fixtures should remain in place. Package-local tests prove package isolation; repo-level tests prove OpenPencil `.fig` behavior did not regress.
+
+## Migration sequence
+
+1. Add `packages/kiwi` with copied runtime/schema files and package-local tests, but do not update production imports yet.
+2. Make `@open-pencil/core/kiwi` re-export from `@open-pencil/kiwi` for schema runtime and codec-only APIs.
+3. Update internal core imports that only need schema runtime or codec APIs to public `@open-pencil/kiwi` exports.
+4. Keep `.fig` import/export, node-change conversion, and instance override policy in core until `@open-pencil/fig` exists.
+5. Run:
+
+```sh
+cd packages/kiwi && bun run check
+bun test tests/engine/kiwi/schema-runtime.test.ts tests/engine/io/fig/roundtrip/basic.test.ts
+bun run check
+```
+
+6. Only after the package is stable, start the `@open-pencil/fig` split for `.fig` container/read/write and SceneGraph conversion policy.
+
+## Do not do yet
+
+- Do not move `NodeChange` ⇄ `SceneNode` conversion into `@open-pencil/kiwi`.
+- Do not make `@open-pencil/kiwi` depend on `@open-pencil/core`.
+- Do not widen app/CLI imports to private package source paths.
+- Do not guess or rewrite Figma schema fields during the split.
+- Do not remove `@open-pencil/core/kiwi` compatibility exports in the first migration.
diff --git a/packages/docs/development/package-split.md b/packages/docs/development/package-split.md
index 230b2f7d9..0ae0c1c0b 100644
--- a/packages/docs/development/package-split.md
+++ b/packages/docs/development/package-split.md
@@ -15,6 +15,8 @@ OpenPencil currently keeps file-format internals in `@open-pencil/core` while `@
 - `@open-pencil/dom-css` owns DesignDOM, CSS runtimes, HTML/JSX/Tailwind projection, and SceneGraph ⇄ DesignDOM conversion.
 - App, CLI, MCP, and Vue SDK consume packages through public workspace exports only.
 
+See [`kiwi-package-plan.md`](./kiwi-package-plan.md) for the detailed `@open-pencil/kiwi` inventory, dependency blockers, and package-local test plan.
+
 ## Candidate packages
 
 ### `@open-pencil/kiwi`