chore(lint): reject broad unknown type assertions

- Add AST-based lint checks for broad unknown object assertions and local JsonObject aliases
- Centralize JsonObject in core and package-local MCP RPC JSON typing
- Replace baseline Record<string, unknown> assertions with named shared/domain types

lint/plugin.js

@@ -1609,7 +1609,111 @@ const noSiblingDomainPrefixedFiles = createProgramFilenameRule({
   }
 })
 
+function typeParameterNodes(node) {
+  return node?.typeParameters?.params ?? node?.typeArguments?.params ?? []
+}
+
+function isRecordStringUnknownType(node) {
+  if (node?.type !== 'TSTypeReference') return false
+  if (node.typeName?.type !== 'Identifier' || node.typeName.name !== 'Record') return false
+  const params = typeParameterNodes(node)
+  return params[0]?.type === 'TSStringKeyword' && params[1]?.type === 'TSUnknownKeyword'
+}
+
+function hasAstChild(node, predicate, seen = new WeakSet()) {
+  if (!node || typeof node !== 'object') return false
+  if (seen.has(node)) return false
+  seen.add(node)
+  if (predicate(node)) return true
+
+  for (const [key, value] of Object.entries(node)) {
+    if (key === 'parent' || key === 'range' || key === 'loc') continue
+    if (Array.isArray(value)) {
+      if (value.some((child) => hasAstChild(child, predicate, seen))) return true
+    } else if (value && typeof value === 'object' && hasAstChild(value, predicate, seen)) {
+      return true
+    }
+  }
+  return false
+}
+
+function containsRecordStringUnknownType(node) {
+  if (isRecordStringUnknownType(node)) return true
+  if (node?.type === 'TSArrayType') return isRecordStringUnknownType(node.elementType)
+  if (node?.type === 'TSUnionType') return node.types?.some(containsRecordStringUnknownType) ?? false
+  return false
+}
+
+function isUnknownArrayType(node) {
+  return node?.type === 'TSArrayType' && node.elementType?.type === 'TSUnknownKeyword'
+}
+
+function hasInlineUnknownArrayProperty(node) {
+  if (node?.type !== 'TSTypeLiteral') return false
+  return (node.members ?? []).some((member) => {
+    const typeNode = member.typeAnnotation?.typeAnnotation
+    return isUnknownArrayType(typeNode)
+  })
+}
+
+function containsInlineUnknownObjectType(node) {
+  return hasAstChild(node, hasInlineUnknownArrayProperty)
+}
+
+const noBroadUnknownTypeAssertions = {
+  meta: {
+    docs: {
+      description:
+        'Disallow broad unknown object type assertions. Add a named domain type or a type guard instead.'
+    }
+  },
+  create(context) {
+    function check(node) {
+      if (containsRecordStringUnknownType(node.typeAnnotation)) {
+        context.report({
+          node,
+          message:
+            'Do not cast to Record<string, unknown>. Add a named domain type or a type guard.'
+        })
+        return
+      }
+      if (containsInlineUnknownObjectType(node.typeAnnotation)) {
+        context.report({
+          node,
+          message: 'Do not cast to an inline unknown object shape. Add a named domain type.'
+        })
+      }
+    }
+
+    return {
+      TSAsExpression: check,
+      TSTypeAssertion: check
+    }
+  }
+}
+
+const noLocalJsonObjectAliases = {
+  meta: {
+    docs: {
+      description: 'Disallow local JsonObject aliases — import the shared type instead'
+    }
+  },
+  create(context) {
+    return {
+      TSTypeAliasDeclaration(node) {
+        if (node.id?.name !== 'JsonObject') return
+        if (!isRecordStringUnknownType(node.typeAnnotation)) return
+        context.report({
+          node,
+          message: 'Import JsonObject from @open-pencil/core/types instead of declaring a local alias.'
+        })
+      }
+    }
+  }
+}
+
 const noFlatKiwiModules = createProgramFilenameRule({
+
   description: 'Disallow flat top-level Kiwi modules — group code under Kiwi subdomains',
   check(file) {
     const marker = '/packages/core/src/kiwi/'
@@ -1664,6 +1768,8 @@ const plugin = {
     'no-direct-storage-access': noDirectStorageAccess,
     'no-broad-double-cast': noBroadDoubleCast,
     'no-unknown-record-double-cast': noUnknownRecordDoubleCast,
+    'no-broad-unknown-type-assertions': noBroadUnknownTypeAssertions,
+    'no-local-json-object-aliases': noLocalJsonObjectAliases,
     'no-ts-suppression-comments': noTsSuppressionComments,
     'no-function-type': noFunctionType,
     'no-reflect-delete-global-this-outside-tests': noReflectDeleteGlobalThisOutsideTests,

oxlint.json

@@ -174,6 +174,8 @@
     "open-pencil/no-deep-parent-relative-imports": "error",
     "open-pencil/no-broad-double-cast": "error",
     "open-pencil/no-unknown-record-double-cast": "error",
+    "open-pencil/no-broad-unknown-type-assertions": "error",
+    "open-pencil/no-local-json-object-aliases": "error",
     "open-pencil/no-ts-suppression-comments": "error",
     "open-pencil/no-reflect-delete-global-this-outside-tests": "error",
     "open-pencil/no-core-browser-globals": "error",

packages/core/src/clipboard/openpencil.ts

@@ -1,6 +1,7 @@
 import { deflateSync, inflateSync } from 'fflate'
 
 import type { SceneGraph, SceneNode } from '#core/scene-graph'
+import type { JsonObject } from '#core/types'
 
 // --- Internal copy/paste (OpenPencil ↔ OpenPencil) ---
 
@@ -40,7 +41,7 @@ export function parseOpenPencilClipboard(html: string): OpenPencilClipboardData
   return null
 }
 
-function restoreTextPictures(nodes: Array<Record<string, unknown>>): void {
+function restoreTextPictures(nodes: JsonObject[]): void {
   for (const node of nodes) {
     if (typeof node.textPicture === 'string') {
       node.textPicture = Uint8Array.fromBase64(node.textPicture)
@@ -92,7 +93,7 @@ function collectNodeTree(
   nodes: SceneNode[],
   graph: SceneGraph,
   textPictureBuilder?: TextPictureBuilder
-): Array<Record<string, unknown>> {
+): JsonObject[] {
   return nodes.map((node) => {
     const children = graph.getChildren(node.id)
     const serialized: Record<string, unknown> = { ...node }

packages/core/src/design-jsx/props-overrides.ts

@@ -1,6 +1,7 @@
 import { colorToFill, parseColor } from '#core/color'
 import { TRANSPARENT } from '#core/constants'
 import type { GridTrack, LayoutMode, SceneNode, Stroke } from '#core/scene-graph'
+import type { JsonObject } from '#core/types'
 
 const WEIGHT_MAP: Record<string, number> = {
   normal: 400,
@@ -83,7 +84,7 @@ function normalizeStyleProps(props: Record<string, unknown>): Record<string, unk
   const style = props.style
   if (style === null || typeof style !== 'object' || Array.isArray(style)) return props
 
-  const source = style as Record<string, unknown>
+  const source = style as JsonObject
   const normalized = { ...props }
   const copyIfUnset = (from: string, to: string, convert?: (value: unknown) => unknown): void => {
     if (normalized[to] !== undefined || source[from] === undefined) return

packages/core/src/design-jsx/tree.ts

@@ -15,6 +15,8 @@ export function isTreeNode(x: unknown): x is TreeNode {
   )
 }
 
+type FunctionComponent = (props: Record<string, unknown>) => unknown
+
 interface ReactElement {
   type: unknown
   props: Record<string, unknown>
@@ -35,10 +37,8 @@ export function resolveToTree(element: unknown, depth = 0): TreeNode | null {
   if (!isReactElement(element)) return null
 
   if (typeof element.type === 'function') {
-    return resolveToTree(
-      (element.type as (p: Record<string, unknown>) => unknown)(element.props),
-      depth + 1
-    )
+    const component = element.type as FunctionComponent
+    return resolveToTree(component(element.props), depth + 1)
   }
 
   if (typeof element.type === 'string') {

packages/core/src/editor/text/session.ts

@@ -2,6 +2,7 @@ import type { Paragraph } from 'canvaskit-wasm'
 
 import type { SceneNode, StyleRun } from '#core/scene-graph'
 import { copyStyleRuns } from '#core/scene-graph/copy'
+import type { JsonObject } from '#core/types'
 
 export type TextEditSizeSnapshot = Partial<Pick<SceneNode, 'width' | 'height'>>
 
@@ -103,8 +104,8 @@ function deepEqual(a: unknown, b: unknown): boolean {
     if (!Array.isArray(a) || !Array.isArray(b) || a.length !== b.length) return false
     return a.every((item, index) => deepEqual(item, b[index]))
   }
-  const aRecord = a as Record<string, unknown>
-  const bRecord = b as Record<string, unknown>
+  const aRecord = a as JsonObject
+  const bRecord = b as JsonObject
   const aKeys = Object.keys(aRecord)
   const bKeys = Object.keys(bRecord)
   if (aKeys.length !== bKeys.length) return false

packages/core/src/kiwi/fig/instance-overrides/index.ts

@@ -13,6 +13,7 @@ export type {
 import { guidToString } from '#core/kiwi/fig/node-change/convert'
 import type { SceneGraph, SceneNode } from '#core/scene-graph'
 import { copyFills, copyStyleRuns } from '#core/scene-graph/copy'
+import type { JsonObject } from '#core/types'
 
 import { applyComponentProperties } from './component-props'
 import { applyConstraintScaling } from './constraints'
@@ -44,7 +45,7 @@ function buildKiwiPropertyNodes(
 ): Set<string> {
   const result = new Set<string>()
   for (const [nodeId, change] of changedNodeEntries(changeMap, guidToNodeId)) {
-    const nc = change as Record<string, unknown>
+    const nc = change as JsonObject
     const node = graph.getNode(nodeId)
     if (!node?.componentId) continue
     const comp = graph.getNode(node.componentId)

packages/core/src/kiwi/fig/instance-overrides/symbol/patches.ts

@@ -1,6 +1,10 @@
 import type { GUID } from '#core/kiwi/fig/codec'
 import type { OverridePatch } from '#core/kiwi/fig/instance-overrides/patches'
-import type { OverrideContext, SymbolOverride } from '#core/kiwi/fig/instance-overrides/types'
+import type {
+  OverrideContext,
+  SymbolOverride,
+  SymbolOverrideFields
+} from '#core/kiwi/fig/instance-overrides/types'
 import { guidToString, VARIABLE_BINDING_FIELDS_INVERSE } from '#core/kiwi/fig/node-change/convert'
 import { applyStyleRefsToFields } from '#core/kiwi/fig/node-change/style-refs'
 
@@ -61,21 +65,16 @@ function resolveFloatVariable(
 
 function applyVariableRadiusOverrides(
   ctx: OverrideContext,
-  fields: Record<string, unknown>,
+  fields: SymbolOverrideFields,
   props: ReturnType<typeof convertOverrideToProps>
 ): void {
-  const entries = (fields.variableConsumptionMap as { entries?: unknown[] } | undefined)?.entries
+  const entries = fields.variableConsumptionMap?.entries
   if (!entries?.length) return
   const assetRefs = buildAssetRefMap(ctx)
   for (const entry of entries) {
-    if (!entry || typeof entry !== 'object') continue
-    const variableEntry = entry as {
-      variableField?: string
-      variableData?: { value?: { alias?: AliasRef } }
-    }
-    const variableField = variableEntry.variableField
+    const variableField = entry.variableField
     if (!variableField || !VARIABLE_RADIUS_FIELDS.has(variableField)) continue
-    const alias = variableEntry.variableData?.value?.alias
+    const alias = entry.variableData?.value?.alias
     const id = alias ? resolveAliasId(alias, assetRefs) : undefined
     const value = id ? resolveFloatVariable(ctx, id, assetRefs) : undefined
     if (typeof value !== 'number') continue
@@ -98,11 +97,14 @@ export function patchFromSymbolOverride(
     patch.swapComponentId = ctx.guidToNodeId.get(swapGuid)
   }
 
-  const { guidPath: _, overriddenSymbolID: _s, componentPropAssignments: _c, ...fields } = ov
+  const fields: SymbolOverrideFields = { ...ov }
+  delete fields.guidPath
+  delete fields.overriddenSymbolID
+  delete fields.componentPropAssignments
   if (Object.keys(fields).length > 0) {
     applyStyleRefsToFields(ctx.changeMap, fields)
-    const props = convertOverrideToProps(fields as Record<string, unknown>)
-    applyVariableRadiusOverrides(ctx, fields as Record<string, unknown>, props)
+    const props = convertOverrideToProps(fields)
+    applyVariableRadiusOverrides(ctx, fields, props)
     if (Object.keys(props).length > 0) patch.props = props
   }
 

packages/core/src/kiwi/fig/instance-overrides/types.ts

@@ -1,4 +1,4 @@
-import type { GUID, NodeChange } from '#core/kiwi/fig/codec'
+import type { GUID, NodeChange, VariableConsumptionEntry } from '#core/kiwi/fig/codec'
 import type { SceneGraph } from '#core/scene-graph'
 import type { Matrix, Vector } from '#core/types'
 
@@ -8,6 +8,12 @@ export interface SymbolOverride {
   guidPath?: { guids?: GUID[] }
   overriddenSymbolID?: GUID
   componentPropAssignments?: ComponentPropAssignment[]
+  variableConsumptionMap?: { entries?: VariableConsumptionEntry[] }
+  [key: string]: unknown
+}
+
+export interface SymbolOverrideFields {
+  variableConsumptionMap?: { entries?: VariableConsumptionEntry[] }
   [key: string]: unknown
 }
 

packages/core/src/kiwi/fig/node-change/convert.ts

@@ -543,10 +543,20 @@ function componentPropValueToString(value: unknown): string {
   return propValue.guidValue ? guidToString(propValue.guidValue) : ''
 }
 
+interface RawComponentPropDef {
+  id?: GUID
+  name?: string
+  type?: string
+  initialValue?: unknown
+}
+
+interface RawSymbolData {
+  symbolOverrides?: unknown[]
+  uniformScaleFactor?: number
+}
+
 function extractComponentPropertyDefs(nc: NodeChange): ComponentPropertyDefinition[] {
-  const defs = nc.componentPropDefs as
-    | Array<{ id?: GUID; name?: string; type?: string; initialValue?: unknown }>
-    | undefined
+  const defs = nc.componentPropDefs as RawComponentPropDef[] | undefined
   if (!defs?.length) return []
   const result: ComponentPropertyDefinition[] = []
   for (const def of defs) {
@@ -852,9 +862,7 @@ function extractFigmaSymbolMetadata(
   | 'derivedSymbolDataLayoutVersion'
   | 'uniformScaleFactor'
 > {
-  const sd = nc.symbolData as
-    | { symbolOverrides?: unknown[]; uniformScaleFactor?: number }
-    | undefined
+  const sd = nc.symbolData as RawSymbolData | undefined
   return {
     symbolOverrides: preserveFigmaPayloadBlobs(sd?.symbolOverrides ?? [], blobs) as unknown[],
     componentPropAssignments: preserveFigmaPayloadBlobs(

packages/core/src/kiwi/fig/node-change/export-node.ts

@@ -141,11 +141,36 @@ const SUPPORTED_VARIABLE_DATA_TYPES = new Set([
   'PROP_REF'
 ])
 
-function isSupportedVariableMapEntry(value: unknown): boolean {
-  if (!value || typeof value !== 'object') return false
-  const entry = value as {
-    variableData?: { dataType?: string; value?: { propRefValue?: unknown } }
+interface FigmaPayloadVariableMap {
+  entries?: unknown[]
+}
+
+interface FigmaPayloadVariableMapEntry {
+  variableData?: { dataType?: string; value?: { propRefValue?: unknown } }
+}
+
+interface ColorVarCarrier {
+  colorVar?: {
+    value?: {
+      alias?: {
+        guid?: GUID
+        assetRef?: { key: string; version?: string }
+      }
+    }
   }
+}
+
+function isFigmaPayloadVariableMap(value: unknown): value is FigmaPayloadVariableMap {
+  return !!value && typeof value === 'object' && !Array.isArray(value) && 'entries' in value
+}
+
+function isFigmaPayloadVariableMapEntry(value: unknown): value is FigmaPayloadVariableMapEntry {
+  return !!value && typeof value === 'object' && !Array.isArray(value)
+}
+
+function isSupportedVariableMapEntry(value: unknown): boolean {
+  if (!isFigmaPayloadVariableMapEntry(value)) return false
+  const entry = value
   const dataType = entry.variableData?.dataType
   return (
     (typeof dataType === 'string' && SUPPORTED_VARIABLE_DATA_TYPES.has(dataType)) ||
@@ -154,10 +179,8 @@ function isSupportedVariableMapEntry(value: unknown): boolean {
 }
 
 function isPropRefVariableMapEntry(value: unknown): boolean {
-  if (!value || typeof value !== 'object') return false
-  const entry = value as {
-    variableData?: { dataType?: string; value?: { propRefValue?: unknown } }
-  }
+  if (!isFigmaPayloadVariableMapEntry(value)) return false
+  const entry = value
   return entry.variableData?.dataType === 'PROP_REF' || !!entry.variableData?.value?.propRefValue
 }
 
@@ -167,8 +190,8 @@ function materializeSafeVariableMap(
   options: MaterializeFigmaPayloadOptions,
   predicate: (value: unknown) => boolean
 ): unknown {
-  if (!value || typeof value !== 'object' || Array.isArray(value)) return undefined
-  const entries = (value as { entries?: unknown[] }).entries?.filter(predicate) ?? []
+  if (!isFigmaPayloadVariableMap(value)) return undefined
+  const entries = value.entries?.filter(predicate) ?? []
   if (entries.length === 0) return undefined
   return { entries: entries.map((entry) => materializeFigmaPayload(entry, blobs, options)) }
 }
@@ -362,16 +385,13 @@ function applyRawFigmaNodeFields(
  */
 function convertColorVarAssetRefs<T>(paints: T, assetRefToVarGuid: Map<string, GUID>): T {
   if (!Array.isArray(paints)) return paints
-  const result = paints.map((paint: Record<string, unknown>) => {
-    const colorVar = paint.colorVar as Record<string, unknown> | undefined
-    if (!colorVar) return paint
-    const value = colorVar.value as Record<string, unknown> | undefined
-    if (!value) return paint
-    const alias = value.alias as Record<string, unknown> | undefined
-    if (!alias) return paint
-    // If alias already has guid, nothing to convert
+  const result = paints.map((paint: ColorVarCarrier) => {
+    const colorVar = paint.colorVar
+    const value = colorVar?.value
+    const alias = value?.alias
+    if (!colorVar || !value || !alias) return paint
     if (alias.guid) return paint
-    const assetRef = alias.assetRef as { key: string; version?: string } | undefined
+    const assetRef = alias.assetRef
     if (!assetRef?.key) return paint
     // Look up by key@version first, then by key alone
     const lookupKey = assetRef.version ? `${assetRef.key}@${assetRef.version}` : assetRef.key

packages/core/src/kiwi/fig/node-change/serialize.ts

@@ -4,6 +4,7 @@ import { buildDerivedTextData as buildSharedDerivedTextData } from '#core/text/d
 import { normalizeFontFamily, weightToFigmaStyle, weightToStyle } from '#core/text/fonts'
 import { getGlyphOutlineMetricsSync } from '#core/text/opentype'
 import { encodeVectorNetworkBlob, buildStyleOverrideTable } from '#core/vector'
+
 export {
   buildFigKiwi,
   decompressFigKiwiData,
@@ -15,7 +16,7 @@ export { buildFontDigestMap } from './font/digests'
 
 import type { NodeChange, Paint, VariableConsumptionEntry } from '#core/kiwi/fig/codec'
 import type { SceneGraph, SceneNode } from '#core/scene-graph'
-import type { Color, GUID, Matrix } from '#core/types'
+import type { Color, GUID, JsonObject, Matrix } from '#core/types'
 
 import { guidToString, stringToGuid, VARIABLE_BINDING_FIELDS } from './convert'
 import {
@@ -234,8 +235,7 @@ function serializeCornerRadii(node: SceneNode, nc: KiwiNodeChange): void {
     // the raw Figma data. Figma may emit per-corner radii without setting the
     // independent flag (preserve rectangleCornerRadiiIndependent).
     const rawIndependent = node.source.id
-      ? (node.source.fig.rawNodeFields as Record<string, unknown> | undefined)
-          ?.rectangleCornerRadiiIndependent
+      ? (node.source.fig.rawNodeFields as JsonObject | undefined)?.rectangleCornerRadiiIndependent
       : undefined
     nc.rectangleCornerRadiiIndependent =
       typeof rawIndependent === 'boolean' ? rawIndependent : node.independentCorners

packages/core/src/kiwi/fig/parse/core.ts

@@ -40,6 +40,10 @@ interface FigKiwiPayload {
   version: number
 }
 
+interface CompiledKiwiSchema {
+  decodeMessage(data: Uint8Array): unknown
+}
+
 export function parseFigKiwiContainer(data: Uint8Array): FigKiwiPayload | null {
   const header = new TextDecoder().decode(data.slice(0, 8))
   if (header !== 'fig-kiwi') return null
@@ -124,7 +128,7 @@ export function parseFigBuffer(buffer: ArrayBuffer): FigParseResult {
 
   const schemaBytes = inflateSync(payload.schemaDeflated)
   const schema = decodeBinarySchema(new ByteBuffer(schemaBytes))
-  const compiled = compileSchema(schema) as { decodeMessage(data: Uint8Array): unknown }
+  const compiled = compileSchema(schema) as CompiledKiwiSchema
   const message = compiled.decodeMessage(payload.dataRaw) as FigmaMessage
 
   const nodeChanges = message.nodeChanges

packages/core/src/tools/ai-adapter.ts

@@ -10,6 +10,7 @@ import type { ToolSet, tool as createTool } from 'ai'
 import type * as valibot from 'valibot'
 
 import type { FigmaAPI } from '#core/figma-api'
+import type { JsonObject } from '#core/types'
 
 import type { ToolDef, ParamDef, ParamType } from './schema'
 
@@ -194,7 +195,7 @@ export function toolsToAI(
             value: [{ type: 'media' as const, mediaType: r.mimeType, data: r.base64 }]
           }
         }
-        return { type: 'json' as const, value: output as Record<string, unknown> }
+        return { type: 'json' as const, value: output as JsonObject }
       }
     }
 

packages/core/src/tools/stock-photo/apply.ts

@@ -9,6 +9,10 @@ export interface PhotoRequest {
   orientation?: 'landscape' | 'portrait' | 'square'
 }
 
+interface NodeWithChildren {
+  children: unknown[]
+}
+
 export interface PhotoResult {
   id: string
   photo?: {
@@ -29,7 +33,7 @@ export async function applyPhoto(
   const node = figma.getNodeById(req.id)
   if (!node) return { id: req.id, error: 'Not found' }
 
-  const children = 'children' in node ? (node as { children: unknown[] }).children : []
+  const children = 'children' in node ? (node as NodeWithChildren).children : []
   if (children.length > 0) {
     return { id: req.id, error: `"${node.name}" has children — use a leaf shape` }
   }

packages/core/src/types.ts

@@ -30,3 +30,8 @@ export interface Rect {
   width: number
   height: number
 }
+
+export type JsonPrimitive = string | number | boolean | null
+export type JsonValue = JsonPrimitive | JsonObject | JsonArray
+export type JsonObject = { [key: string]: unknown }
+export type JsonArray = unknown[]

packages/mcp/src/browser-rpc.ts

@@ -2,6 +2,8 @@ import { randomUUID } from 'node:crypto'
 
 import type { WebSocket } from 'ws'
 
+import type { RpcJsonObject } from '#mcp/json'
+
 const RPC_TIMEOUT = 30_000
 
 const APP_NOT_CONNECTED_MESSAGE =
@@ -34,7 +36,7 @@ function stripEnvelope(msg: BrowserMessage): Record<string, unknown> {
 
 function responsePayload(result: unknown): Record<string, unknown> {
   if (result && typeof result === 'object' && !Array.isArray(result)) {
-    return result as Record<string, unknown>
+    return result as RpcJsonObject
   }
   return { result }
 }

packages/mcp/src/json.ts

@@ -0,0 +1 @@
+export type RpcJsonObject = { [key: string]: unknown }

packages/mcp/src/server.ts

@@ -5,6 +5,8 @@ import { resolveCommand } from 'package-manager-detector/commands'
 import { detect, getUserAgent } from 'package-manager-detector/detect'
 import { WebSocketServer } from 'ws'
 
+import type { RpcJsonObject } from '#mcp/json'
+
 import packageJson from '../package.json' with { type: 'json' }
 import { bearerToken, isAuthorized, mcpRequestToken } from './auth'
 import { createBrowserRpcBridge } from './browser-rpc'
@@ -130,8 +132,8 @@ export function startServer(options: ServerOptions = {}) {
       return c.json({ error: 'Invalid request body' }, 400)
     }
     try {
-      body = preprocessRpc(body as Record<string, unknown>)
-      const result = await sendToBrowser(body as Record<string, unknown>)
+      body = preprocessRpc(body as RpcJsonObject)
+      const result = await sendToBrowser(body as RpcJsonObject)
       return c.json(result)
     } catch (e) {
       const msg = e instanceof Error ? e.message : String(e)

packages/mcp/src/tool/registration.ts

@@ -5,6 +5,7 @@ import { z } from 'zod'
 
 import { ALL_TOOLS, CODEGEN_PROMPT } from '@open-pencil/core/tools'
 
+import type { RpcJsonObject } from '#mcp/json'
 import { fail, ok } from '#mcp/result'
 
 import { resolveSafePath, writeToolOutput } from './output'
@@ -37,7 +38,7 @@ export function registerTools(mcpServer: McpServer, options: RegisterToolsOption
           const result = await sendRpc({ command: 'tool', args: { name: def.name, args } })
           const res = result as { ok?: boolean; result?: unknown; error?: string }
           if (res.ok === false) return fail(new Error(res.error))
-          const r = res.result as Record<string, unknown> | undefined
+          const r = res.result as RpcJsonObject | undefined
           const filePath = typeof args.path === 'string' ? args.path : null
           if (r && filePath && resolvedRoot) {
             const written = await writeToolOutput(def.name, r, filePath, resolvedRoot)

scripts/check-locales.ts

@@ -2,6 +2,8 @@
 import { readFileSync, readdirSync } from 'node:fs'
 import { join } from 'node:path'
 
+import type { JsonObject } from '@open-pencil/core/types'
+
 const MESSAGES_PATH = 'packages/vue/src/i18n/messages.ts'
 const LOCALES_DIR = 'packages/vue/src/locales'
 
@@ -23,7 +25,7 @@ for (const file of localeFiles) {
   const extra: string[] = []
 
   for (const [ns, keys] of enKeys) {
-    const localeNs = (data[ns] ?? {}) as Record<string, unknown>
+    const localeNs = (data[ns] ?? {}) as JsonObject
     for (const key of keys) {
       if (!(key in localeNs)) missing.push(`${ns}.${key}`)
     }

src/app/ai/acp/map-update.ts

@@ -1,6 +1,8 @@
 import type { SessionUpdate } from '@agentclientprotocol/sdk'
 import type { UIMessageChunk } from 'ai'
 
+import type { JsonObject } from '@open-pencil/core/types'
+
 export interface MapResult {
   chunks: UIMessageChunk[]
   textStarted: boolean
@@ -86,14 +88,12 @@ export function mapUpdate(update: SessionUpdate, textId: string, textStarted: bo
   return { chunks, textStarted }
 }
 
-export function textFromContent(
-  content: Record<string, unknown>[] | undefined
-): string | undefined {
+export function textFromContent(content: JsonObject[] | undefined): string | undefined {
   if (!content) return undefined
   const parts: string[] = []
   for (const c of content) {
     if (c.type !== 'content') continue
-    const inner = c.content as Record<string, unknown> | undefined
+    const inner = c.content as JsonObject | undefined
     if (inner?.type === 'text' && typeof inner.text === 'string') {
       parts.push(inner.text)
     }

src/app/ai/debug/index.ts

@@ -2,6 +2,7 @@ import type { UIMessage } from 'ai'
 
 import { buildDebugLog } from '@open-pencil/core/tools'
 import type { ToolDebugLog, ToolLogEntry } from '@open-pencil/core/tools'
+import type { JsonObject } from '@open-pencil/core/types'
 
 import { getStepUsages, getToolLogEntries } from '@/app/ai/tools'
 
@@ -154,7 +155,7 @@ export function formatDiagnostics(log: ToolDebugLog): string {
 }
 
 function formatToolPart(part: Record<string, unknown>): string {
-  const inv = part.toolInvocation as Record<string, unknown> | undefined
+  const inv = part.toolInvocation as JsonObject | undefined
   if (inv) {
     const lines = [`  [tool] ${String(inv.toolName)} (${String(inv.state)})`]
     if (inv.args) lines.push(`    args: ${JSON.stringify(inv.args)}`)
@@ -181,7 +182,7 @@ function formatMessageStats(messages: UIMessage[]): string {
     if (msg.role === 'user') userMessages++
     else if (msg.role === 'assistant') assistantMessages++
     for (const part of msg.parts) {
-      const p = part as Record<string, unknown>
+      const p = part as JsonObject
       if (p.type === 'text') {
         totalTextLength += typeof p.text === 'string' ? p.text.length : 0
       } else if (
@@ -244,7 +245,7 @@ export function serializeChatLog(messages: UIMessage[]): string {
     const parts: string[] = []
 
     for (const part of msg.parts) {
-      const p = part as Record<string, unknown>
+      const p = part as JsonObject
       if (p.type === 'text') {
         parts.push(`  ${p.text as string}`)
       } else if (p.type === 'reasoning') {

src/app/automation/bridge/tool-handlers.ts

@@ -2,6 +2,7 @@ import { renderTreeNode } from '@open-pencil/core/design-jsx'
 import type { FigmaAPI } from '@open-pencil/core/figma-api'
 import { computeAllLayouts } from '@open-pencil/core/layout'
 import { ALL_TOOLS } from '@open-pencil/core/tools'
+import type { JsonObject } from '@open-pencil/core/types'
 
 import type { EditorStore } from '@/app/editor/active-store'
 import { ensureGraphFonts } from '@/app/editor/fonts'
@@ -60,18 +61,14 @@ export function createAutomationToolHandler(makeFigma: FigmaFactory) {
 
 function extractNodeIds(result: unknown): string[] {
   if (!result || typeof result !== 'object') return []
-  const obj = result as Record<string, unknown>
+  const obj = result as JsonObject
   if (typeof obj.deleted === 'string') return []
   const ids: string[] = []
   if (typeof obj.id === 'string') ids.push(obj.id)
   if (Array.isArray(obj.results)) {
     for (const item of obj.results) {
-      if (
-        item &&
-        typeof item === 'object' &&
-        typeof (item as Record<string, unknown>).id === 'string'
-      )
-        ids.push((item as Record<string, unknown>).id as string)
+      if (item && typeof item === 'object' && typeof (item as JsonObject).id === 'string')
+        ids.push((item as JsonObject).id as string)
     }
   }
   return ids

src/components/ChatPanel.vue

@@ -18,6 +18,7 @@ import { useI18n } from '@open-pencil/vue'
 
 import type { Chat } from '@ai-sdk/vue'
 import type { UIMessage } from 'ai'
+import type { JsonObject } from '@open-pencil/core/types'
 
 const IS_DEV = import.meta.env.DEV
 
@@ -43,7 +44,7 @@ const isThinking = computed(() => {
   if (last.role !== 'assistant') return true
   const parts = last.parts
   if (parts.length === 0) return true
-  const lastPart = parts[parts.length - 1] as Record<string, unknown>
+  const lastPart = parts[parts.length - 1] as JsonObject
   if (lastPart.type === 'step-start') return true
   if ('toolCallId' in lastPart && lastPart.state === 'output-available') return true
   if ('toolCallId' in lastPart && lastPart.state === 'output-error') return true

tests/engine/figma/api/serialization.test.ts

@@ -2,6 +2,10 @@ import { describe, expect, test } from 'bun:test'
 
 import { createAPI } from './helpers'
 
+interface SerializedNodeWithChildren {
+  children?: unknown[]
+}
+
 describe('serialization', () => {
   test('toJSON returns clean object', () => {
     const api = createAPI()
@@ -20,7 +24,7 @@ describe('serialization', () => {
     const frame = api.createFrame()
     const rect = api.createRectangle()
     frame.appendChild(rect)
-    const json = frame.toJSON() as { children?: unknown[] }
+    const json = frame.toJSON() as SerializedNodeWithChildren
     expect(json.children).toBeDefined()
     expect(json.children?.length).toBe(1)
   })

tests/engine/io/fig/export/text.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, setDefaultTimeout, test } from 'bun:test'
 
 import { exportFigFile, initCodec, parseFigFile, SceneGraph } from '@open-pencil/core'
+import type { JsonObject } from '@open-pencil/core/types'
 
 import { expectDefined } from '#tests/helpers/assert'
 import { parseFixture } from '#tests/helpers/fig-fixtures'
@@ -95,7 +96,7 @@ describe('text node export', () => {
     const dataRaw = inflateSync(chunks?.[1] ?? new Uint8Array())
     const message = compiled.decodeMessage(dataRaw)
 
-    const nodeChanges = message.nodeChanges as Array<Record<string, unknown>>
+    const nodeChanges = message.nodeChanges as JsonObject[]
     const textNc = nodeChanges.find((nc) => nc.type === 'TEXT')
     expect(textNc).toBeDefined()
 
@@ -149,19 +150,19 @@ describe('text node export', () => {
       decodeMessage(data: Uint8Array): Record<string, unknown>
     }
     const message = compiled.decodeMessage(inflateSync(chunks?.[1] ?? new Uint8Array()))
-    const nodeChanges = message.nodeChanges as Array<Record<string, unknown>>
+    const nodeChanges = message.nodeChanges as JsonObject[]
     const textNc = expectDefined(
       nodeChanges.find((nc) => nc.type === 'TEXT'),
       'text node change'
     )
-    const derivedTextData = textNc.derivedTextData as Record<string, unknown>
+    const derivedTextData = textNc.derivedTextData as JsonObject
     const fontMetaData = expectDefined(
-      derivedTextData.fontMetaData as Array<Record<string, unknown>> | undefined,
+      derivedTextData.fontMetaData as JsonObject[] | undefined,
       'font metadata'
     )
 
-    expect((textNc.fontName as Record<string, unknown>).style).toBe('Semi Bold')
-    expect((fontMetaData[0].key as Record<string, unknown>).style).toBe('Semi Bold')
+    expect((textNc.fontName as JsonObject).style).toBe('Semi Bold')
+    expect((fontMetaData[0].key as JsonObject).style).toBe('Semi Bold')
   })
 
   test('auto-layout text children export height auto-resize for Figma rendering', async () => {
@@ -200,7 +201,7 @@ describe('text node export', () => {
       decodeMessage(data: Uint8Array): Record<string, unknown>
     }
     const message = compiled.decodeMessage(inflateSync(chunks?.[1] ?? new Uint8Array()))
-    const nodeChanges = message.nodeChanges as Array<Record<string, unknown>>
+    const nodeChanges = message.nodeChanges as JsonObject[]
     const textNc = expectDefined(
       nodeChanges.find((nc) => nc.type === 'TEXT'),
       'text node change'
@@ -249,16 +250,14 @@ describe('text node export', () => {
     const dataRaw = inflateSync(chunks?.[1] ?? new Uint8Array())
     const message = compiled.decodeMessage(dataRaw)
 
-    const nodeChanges = message.nodeChanges as Array<Record<string, unknown>>
+    const nodeChanges = message.nodeChanges as JsonObject[]
     const textNc = nodeChanges.find((nc) => nc.type === 'TEXT')
 
-    const derivedTextData = textNc?.derivedTextData as Record<string, unknown> | undefined
-    const fontMetaData = derivedTextData?.fontMetaData as Array<Record<string, unknown>> | undefined
+    const derivedTextData = textNc?.derivedTextData as JsonObject | undefined
+    const fontMetaData = derivedTextData?.fontMetaData as JsonObject[] | undefined
     expect(fontMetaData?.length).toBe(2)
 
-    const families = (fontMetaData ?? []).map(
-      (m) => (m.key as Record<string, unknown>)?.style as string
-    )
+    const families = (fontMetaData ?? []).map((m) => (m.key as JsonObject)?.style as string)
     expect(families).toContain('Bold')
     expect(families).toContain('Regular')
   })

tests/engine/io/fig/roundtrip/exhaustive.test.ts

@@ -11,6 +11,7 @@ import {
   type SceneGraph,
   type SceneNode
 } from '@open-pencil/core'
+import type { JsonObject } from '@open-pencil/core/types'
 
 import {
   type Mismatch,
@@ -169,8 +170,8 @@ function deepCompare(
   for (const k of allKeys) {
     if (depth === 0 && SKIP_KEYS.has(k)) continue
     deepCompare(
-      (a as Record<string, unknown>)[k],
-      (b as Record<string, unknown>)[k],
+      (a as JsonObject)[k],
+      (b as JsonObject)[k],
       key ? `${key}.${k}` : k,
       path,
       opts,
@@ -240,13 +241,7 @@ function compareSceneProps(
     for (const k of new Set([...Object.keys(aNode as object), ...Object.keys(bNode as object)])) {
       if (SKIP_KEYS.has(k)) continue
       if (k === 'source') continue
-      deepCompare(
-        (aNode as Record<string, unknown>)[k],
-        (bNode as Record<string, unknown>)[k],
-        k,
-        p,
-        opts
-      )
+      deepCompare((aNode as JsonObject)[k], (bNode as JsonObject)[k], k, p, opts)
     }
   }
   if (errors.length > 0) throw new Error(`${label} scene props:\n${summarize(errors)}`)
@@ -278,12 +273,12 @@ function compareRawNodeFields(
   for (const [p, aNode] of aNodes) {
     const bNode = bNodes.get(p)
     if (!bNode) continue
-    const aRaw = (aNode as Record<string, unknown>).source as Record<string, unknown> | undefined
-    const bRaw = (bNode as Record<string, unknown>).source as Record<string, unknown> | undefined
-    const aFig = aRaw?.fig as Record<string, unknown> | undefined
-    const bFig = bRaw?.fig as Record<string, unknown> | undefined
-    const aFields = aFig?.rawNodeFields as Record<string, unknown> | undefined
-    const bFields = bFig?.rawNodeFields as Record<string, unknown> | undefined
+    const aRaw = (aNode as JsonObject).source as JsonObject | undefined
+    const bRaw = (bNode as JsonObject).source as JsonObject | undefined
+    const aFig = aRaw?.fig as JsonObject | undefined
+    const bFig = bRaw?.fig as JsonObject | undefined
+    const aFields = aFig?.rawNodeFields as JsonObject | undefined
+    const bFields = bFig?.rawNodeFields as JsonObject | undefined
     if (!aFields && !bFields) continue
     deepCompareRaw(aFields, bFields, '', p, opts)
   }
@@ -319,8 +314,8 @@ function deepCompareRaw(
     b !== null &&
     !Array.isArray(a)
   ) {
-    const aObj = a as Record<string, unknown>
-    const bObj = b as Record<string, unknown>
+    const aObj = a as JsonObject
+    const bObj = b as JsonObject
     const allKeys = new Set([...Object.keys(aObj), ...Object.keys(bObj)])
     for (const k of allKeys) {
       const vfn2 = opts.verifiers.get(k)
@@ -386,8 +381,8 @@ function deepCompareRaw(
     return
   }
 
-  const aObj = a as Record<string, unknown>
-  const bObj = b as Record<string, unknown>
+  const aObj = a as JsonObject
+  const bObj = b as JsonObject
   const allKeys = new Set([...Object.keys(aObj), ...Object.keys(bObj)])
   for (const k of allKeys) {
     const fullKey = key ? `${key}.${k}` : k

tests/engine/io/fig/roundtrip/helpers.ts

@@ -1,4 +1,5 @@
 import type { SceneGraph, SceneNode } from '@open-pencil/core'
+import type { JsonObject } from '@open-pencil/core/types'
 
 import { verifyComponentPropDefs, verifyDerivedTextData } from './raw-verifiers/helpers'
 
@@ -193,17 +194,20 @@ function verifyVariableConsumption(
   verifyBEntries(aEntries, bEntries, ctx)
 }
 
+interface VariableConsumptionMapShape {
+  entries?: Array<{
+    variableData?: { value?: { alias?: { guid?: unknown; assetRef?: unknown } } }
+    variableField?: string
+  }>
+}
+
 function verifyVarAlias(a: unknown, b: unknown): boolean {
-  const aVal = a as Record<string, unknown> | undefined
-  const bVal = b as Record<string, unknown> | undefined
+  const aVal = a as JsonObject | undefined
+  const bVal = b as JsonObject | undefined
   if (!aVal && !bVal) return true
   if (!aVal || !bVal) return false
-  const aAlias = (aVal.value as Record<string, unknown>)?.alias as
-    | Record<string, unknown>
-    | undefined
-  const bAlias = (bVal.value as Record<string, unknown>)?.alias as
-    | Record<string, unknown>
-    | undefined
+  const aAlias = (aVal.value as JsonObject)?.alias as JsonObject | undefined
+  const bAlias = (bVal.value as JsonObject)?.alias as JsonObject | undefined
   const aGuid = aAlias?.guid
   const bGuid = bAlias?.guid
   const aRef = aAlias?.assetRef
@@ -229,7 +233,7 @@ export const RAW_VERIFIERS = new Map<string, Verifier>([
     'letterSpacing',
     (ctx) => {
       if (isIdempotent(ctx)) return JSON.stringify(ctx.a) === JSON.stringify(ctx.b)
-      const g1raw = ctx.b as Record<string, unknown> | undefined
+      const g1raw = ctx.b as JsonObject | undefined
       const node = ctx.aNodes.get(ctx.path)
       if (!node || node.fontSize == null) return true
       const expected = node.letterSpacing
@@ -248,7 +252,7 @@ export const RAW_VERIFIERS = new Map<string, Verifier>([
     'lineHeight',
     (ctx) => {
       if (isIdempotent(ctx)) return JSON.stringify(ctx.a) === JSON.stringify(ctx.b)
-      const g1raw = ctx.b as Record<string, unknown> | undefined
+      const g1raw = ctx.b as JsonObject | undefined
       const node = ctx.aNodes.get(ctx.path)
       if (!node || node.lineHeight == null) return true
       const expected = node.lineHeight
@@ -260,22 +264,8 @@ export const RAW_VERIFIERS = new Map<string, Verifier>([
     'variableConsumptionMap',
     (ctx) => {
       if (isIdempotent(ctx)) return JSON.stringify(ctx.a) === JSON.stringify(ctx.b)
-      const ga = ctx.a as
-        | {
-            entries?: Array<{
-              variableData?: { value?: { alias?: { guid?: unknown; assetRef?: unknown } } }
-              variableField?: string
-            }>
-          }
-        | undefined
-      const gb = ctx.b as
-        | {
-            entries?: Array<{
-              variableData?: { value?: { alias?: { guid?: unknown; assetRef?: unknown } } }
-              variableField?: string
-            }>
-          }
-        | undefined
+      const ga = ctx.a as VariableConsumptionMapShape | undefined
+      const gb = ctx.b as VariableConsumptionMapShape | undefined
       verifyVariableConsumption(ga, gb, ctx)
       return true
     }

tests/engine/io/fig/roundtrip/raw-verifiers/helpers.ts

@@ -1,8 +1,10 @@
+import type { JsonObject } from '@open-pencil/core/types'
+
 import type { VerifierContext } from '../helpers'
 
 function asRecord(value: unknown): Record<string, unknown> | undefined {
   return value && typeof value === 'object' && !Array.isArray(value)
-    ? (value as Record<string, unknown>)
+    ? (value as JsonObject)
     : undefined
 }
 
@@ -45,8 +47,8 @@ function verifySingleFontMetadata(
   i: number,
   ctx: VerifierContext
 ): void {
-  const amKey = am.key as Record<string, unknown> | undefined
-  const bmKey = bm.key as Record<string, unknown> | undefined
+  const amKey = am.key as JsonObject | undefined
+  const bmKey = bm.key as JsonObject | undefined
   if (amKey?.family !== bmKey?.family) {
     ctx.errors.push({
       path: ctx.path,
@@ -79,11 +81,7 @@ function verifySingleFontMetadata(
   verifyFontDigest(am.fontDigest, bm.fontDigest, i, ctx)
 }
 
-function verifyFontMetadata(
-  aMeta: Record<string, unknown>[],
-  bMeta: Record<string, unknown>[],
-  ctx: VerifierContext
-): void {
+function verifyFontMetadata(aMeta: JsonObject[], bMeta: JsonObject[], ctx: VerifierContext): void {
   for (let i = 0; i < aMeta.length; i++) {
     verifySingleFontMetadata(aMeta[i], bMeta[i], i, ctx)
   }
@@ -140,8 +138,8 @@ export function verifyDerivedTextData(ctx: VerifierContext): boolean {
     })
   }
 
-  const aMeta = (aVal.fontMetaData as Record<string, unknown>[]) ?? []
-  const bMeta = (bVal.fontMetaData as Record<string, unknown>[]) ?? []
+  const aMeta = (aVal.fontMetaData as JsonObject[]) ?? []
+  const bMeta = (bVal.fontMetaData as JsonObject[]) ?? []
   if (aMeta.length !== bMeta.length) {
     ctx.errors.push({
       path: ctx.path,
@@ -208,8 +206,8 @@ function verifySingleComponentPropDef(
 }
 
 export function verifyComponentPropDefs(a: unknown, b: unknown): boolean {
-  const aDefs = a as Record<string, unknown>[] | undefined
-  const bDefs = b as Record<string, unknown>[] | undefined
+  const aDefs = a as JsonObject[] | undefined
+  const bDefs = b as JsonObject[] | undefined
   if (!aDefs && !bDefs) return true
   if (!aDefs || !bDefs) return false
   if (aDefs.length !== bDefs.length) return false

tests/engine/kiwi/serialize-fixes/auto-layout/transforms.test.ts

@@ -40,7 +40,7 @@ describe('Fix 1: auto-layout child transforms', () => {
       { value: 100 },
       graph,
       blobs
-    ) as Record<string, unknown>[]
+    )
 
     // changes[0] = parent, changes[1] = child
     const childNc = expectDefined(
@@ -81,7 +81,7 @@ describe('Fix 1: auto-layout child transforms', () => {
       { value: 100 },
       graph,
       blobs
-    ) as Record<string, unknown>[]
+    )
 
     const absNc = expectDefined(
       changes.find((nc) => nc.name === 'AbsChild'),
@@ -119,7 +119,7 @@ describe('Fix 1: auto-layout child transforms', () => {
       { value: 100 },
       graph,
       blobs
-    ) as Record<string, unknown>[]
+    )
 
     const childNc = expectDefined(
       changes.find((nc) => nc.name === 'Child'),
@@ -167,7 +167,7 @@ describe('Fix 1: auto-layout child transforms', () => {
       { value: 100 },
       graph,
       blobs
-    ) as Record<string, unknown>[]
+    )
 
     const parentNc = expectDefined(
       changes.find((nc) => nc.name === 'Checked List'),
@@ -215,7 +215,7 @@ describe('Fix 1: auto-layout child transforms', () => {
       { value: 100 },
       graph,
       blobs
-    ) as Record<string, unknown>[]
+    )
 
     const itemNc = expectDefined(
       changes.find((nc) => nc.name === 'Item'),

tests/engine/kiwi/serialize-fixes/borders/take-space.test.ts

@@ -18,7 +18,7 @@ describe('Fix 3: bordersTakeSpace serialization', () => {
       strokesIncludedInLayout: true
     })
 
-    const changes = toKiwi(node, graph) as Record<string, unknown>[]
+    const changes = toKiwi(node, graph)
     expect(changes[0].bordersTakeSpace).toBe(true)
   })
 
@@ -35,7 +35,7 @@ describe('Fix 3: bordersTakeSpace serialization', () => {
       strokesIncludedInLayout: false
     })
 
-    const changes = toKiwi(node, graph) as Record<string, unknown>[]
+    const changes = toKiwi(node, graph)
     expect(changes[0].bordersTakeSpace).toBe(false)
   })
 
@@ -50,7 +50,7 @@ describe('Fix 3: bordersTakeSpace serialization', () => {
       strokesIncludedInLayout: true
     })
 
-    const changes = toKiwi(node, graph) as Record<string, unknown>[]
+    const changes = toKiwi(node, graph)
     expect(changes[0].bordersTakeSpace).toBeUndefined()
   })
 })

tests/engine/kiwi/serialize-fixes/font/family.test.ts

@@ -93,7 +93,7 @@ describe('Fix 5: font family normalization in derivedTextData', () => {
       fontSize: 14
     })
 
-    const changes = toKiwi(node, graph) as Record<string, unknown>[]
+    const changes = toKiwi(node, graph)
     expect(changes[0].fontName.family).toBe('DM Sans')
   })
 })

tests/engine/kiwi/serialize-fixes/frame/mask.test.ts

@@ -17,7 +17,7 @@ describe('Fix 2: frameMaskDisabled is inverse of clipsContent', () => {
       height: 100
     })
 
-    const changes = toKiwi(node, graph) as Record<string, unknown>[]
+    const changes = toKiwi(node, graph)
     expect(changes[0].frameMaskDisabled).toBe(true)
   })
 
@@ -32,7 +32,7 @@ describe('Fix 2: frameMaskDisabled is inverse of clipsContent', () => {
       clipsContent: true
     })
 
-    const changes = toKiwi(node, graph) as Record<string, unknown>[]
+    const changes = toKiwi(node, graph)
     expect(changes[0].frameMaskDisabled).toBe(false)
   })
 
@@ -47,7 +47,7 @@ describe('Fix 2: frameMaskDisabled is inverse of clipsContent', () => {
       clipsContent: false
     })
 
-    const changes = toKiwi(node, graph) as Record<string, unknown>[]
+    const changes = toKiwi(node, graph)
     expect(changes[0].frameMaskDisabled).toBe(true)
   })
 

tests/engine/kiwi/serialize-fixes/integration.test.ts

@@ -67,7 +67,7 @@ describe('Integration: auto-layout component with all fixes', () => {
       { value: 100 },
       graph,
       blobs
-    ) as Record<string, unknown>[]
+    )
 
     const cardNc = changes[0]
     const titleNc = expectDefined(

tests/engine/kiwi/serialize-fixes/line/height.test.ts

@@ -22,7 +22,7 @@ describe('Fix 4: text lineHeight serialization', () => {
       lineHeight: 24
     })
 
-    const changes = toKiwi(node, graph) as Record<string, unknown>[]
+    const changes = toKiwi(node, graph)
     expect(changes[0].lineHeight).toEqual({ value: 24, units: 'PIXELS' })
   })
 
@@ -40,7 +40,7 @@ describe('Fix 4: text lineHeight serialization', () => {
       fontSize: 16
     })
 
-    const changes = toKiwi(node, graph) as Record<string, unknown>[]
+    const changes = toKiwi(node, graph)
     expect(changes[0].lineHeight).toBeUndefined()
   })
 

tests/engine/mcp/tools.test.ts

@@ -4,6 +4,16 @@ import { ALL_TOOLS, FigmaAPI, SceneGraph, computeAllLayouts, parseFigFile } from
 
 import { expectDefined } from '#tests/helpers/assert'
 
+interface PageTreeResult {
+  page: string
+  children: PageTreeNode[]
+}
+
+interface PageTreeNode {
+  id: string
+  children?: PageTreeNode[]
+}
+
 describe('MCP tool execution', () => {
   function setup() {
     const graph = new SceneGraph()
@@ -40,10 +50,7 @@ describe('MCP tool execution', () => {
 
   test('get_page_tree returns page hierarchy', () => {
     const { api } = setup()
-    const result = findTool('get_page_tree').execute(api, {}) as {
-      page: string
-      children: unknown[]
-    }
+    const result = findTool('get_page_tree').execute(api, {}) as PageTreeResult
     expect(result.page).toBe('Page 1')
     expect(result.children).toBeArray()
   })
@@ -131,9 +138,7 @@ describe('MCP tool execution', () => {
       parent_id: parent.id
     })
 
-    const tree = findTool('get_page_tree').execute(api, {}) as {
-      children: { id: string; children?: unknown[] }[]
-    }
+    const tree = findTool('get_page_tree').execute(api, {}) as PageTreeResult
     const parentNode = expectDefined(
       tree.children.find((c: { id: string }) => c.id === parent.id),
       'parent tree node'

tests/engine/scene-graph/individual-strokes.test.ts

@@ -242,7 +242,7 @@ describe('Kiwi serialization', () => {
       { value: 100 },
       graph,
       blobs
-    ) as Record<string, unknown>[]
+    )
 
     expect(changes[0].borderStrokeWeightsIndependent).toBe(true)
     expect(changes[0].borderTopWeight).toBe(1)
@@ -263,7 +263,7 @@ describe('Kiwi serialization', () => {
       { value: 100 },
       graph,
       blobs
-    ) as Record<string, unknown>[]
+    )
 
     expect(changes[0].borderStrokeWeightsIndependent).toBeUndefined()
     expect(changes[0].borderTopWeight).toBeUndefined()

tests/engine/scene-graph/undo/mutation.test.ts

@@ -1,6 +1,7 @@
 import { describe, test, expect } from 'bun:test'
 
 import { SceneGraph, UndoManager } from '@open-pencil/core'
+import type { JsonObject } from '@open-pencil/core/types'
 
 import { getNodeOrThrow } from '#tests/helpers/assert'
 
@@ -21,7 +22,7 @@ describe('SceneGraph + UndoManager — updateNode undo integration', () => {
     ) {
       const node = getNodeOrThrow(graph, id)
       const previous = Object.fromEntries(
-        (Object.keys(changes) as string[]).map((k) => [k, (node as Record<string, unknown>)[k]])
+        (Object.keys(changes) as string[]).map((k) => [k, (node as JsonObject)[k]])
       )
       graph.updateNode(id, changes)
       undo.push({

tests/engine/tools/ai-adapter.test.ts

@@ -10,6 +10,11 @@ import { expectDefined } from '#tests/helpers/assert'
 
 type AdapterTool = { execute(args: Record<string, unknown>): Promise<unknown>; description: string }
 
+interface PageTreeToolResult {
+  page: unknown
+  children: unknown[]
+}
+
 function adapterTool(tools: Record<string, unknown>, name: string): AdapterTool {
   return tools[name] as AdapterTool
 }
@@ -93,7 +98,7 @@ describe('AI adapter', () => {
     frame.appendChild(rect)
 
     const getTree = adapterTool(tools, 'get_page_tree')
-    const result = (await getTree.execute({})) as { page: unknown; children: unknown[] }
+    const result = (await getTree.execute({})) as PageTreeToolResult
     expect(result.page).toBeTruthy()
     expect(result.children.length).toBeGreaterThan(0)
   })