diff --git a/packages/core/tests/helpers/fig/nested-binding.ts b/packages/core/tests/helpers/fig/nested-binding.ts
index 7dcfcbeb6..f9f93bc24 100644
--- a/packages/core/tests/helpers/fig/nested-binding.ts
+++ b/packages/core/tests/helpers/fig/nested-binding.ts
@@ -1,4 +1,4 @@
-import type { SymbolData } from '@open-pencil/fig/instance-overrides'
+import { symbolOverridesOf } from '@open-pencil/fig/instance-overrides'
 import type { NodeChange } from '@open-pencil/kiwi/fig/codec'
 
 import { expectDefined } from '../assert'
@@ -13,7 +13,7 @@ export function inheritedNestedBindingRecords(): NodeChange[] {
     changes.find((node) => node.guid?.sessionID === 293733 && node.guid.localID === 8),
     'captured owner'
   )
-  for (const override of (owner.symbolData as SymbolData).symbolOverrides ?? []) {
+  for (const override of symbolOverridesOf(owner)) {
     Reflect.deleteProperty(override, 'parameterConsumptionMap')
   }
   return changes
diff --git a/packages/core/tests/io/formats/fig/export/layout-scale.test.ts b/packages/core/tests/io/formats/fig/export/layout-scale.test.ts
index cd3cab13b..910d0319c 100644
--- a/packages/core/tests/io/formats/fig/export/layout-scale.test.ts
+++ b/packages/core/tests/io/formats/fig/export/layout-scale.test.ts
@@ -5,7 +5,7 @@ import { exportFigFile } from '@open-pencil/core/io'
 import { initCodec } from '@open-pencil/core/kiwi'
 import { computeAllLayouts } from '@open-pencil/core/layout'
 import { materializeDocument, parseFigBuffer } from '@open-pencil/fig'
-import type { SymbolData } from '@open-pencil/fig/instance-overrides'
+import { symbolOverridesOf } from '@open-pencil/fig/instance-overrides'
 import type { NodeChange } from '@open-pencil/kiwi/fig/codec'
 import { hasInstanceOverride } from '@open-pencil/scene-graph'
 import { NestedLayoutScaleFixture, readFixture } from '#core-tests/helpers/fig/fixtures'
@@ -63,7 +63,7 @@ test('scaled padding edits undo and export in the declaring owner space', async
     (node) => node.type === 'INSTANCE' && node.name === 'Scaled outer'
   )
   expect(saved).toBeDefined()
-  const overrides = (saved?.symbolData as SymbolData | undefined)?.symbolOverrides ?? []
+  const overrides = saved ? symbolOverridesOf(saved) : []
   expect(overrides.some((override) => override.stackHorizontalPadding === 14)).toBe(true)
   const { graph: reopened } = materializeDocument(parsed.nodeChanges, parsed.blobs, {
     derivedBounds: true
diff --git a/packages/core/tests/io/formats/fig/export/rescale-export.test.ts b/packages/core/tests/io/formats/fig/export/rescale-export.test.ts
index 399cc7c6f..39341c846 100644
--- a/packages/core/tests/io/formats/fig/export/rescale-export.test.ts
+++ b/packages/core/tests/io/formats/fig/export/rescale-export.test.ts
@@ -5,7 +5,7 @@ import { FigmaAPI } from '@open-pencil/core/figma-api'
 import { exportFigFile } from '@open-pencil/core/io'
 import { initCodec } from '@open-pencil/core/kiwi'
 import { materializeDocument, parseFigBuffer } from '@open-pencil/fig'
-import type { SymbolData } from '@open-pencil/fig/instance-overrides'
+import { symbolDataOf } from '@open-pencil/fig/instance-overrides'
 import { setInstanceOverride } from '@open-pencil/scene-graph'
 
 import { expectDefined } from '#core-tests/helpers/assert'
@@ -53,7 +53,7 @@ for (const scale of [0.5, 2]) {
       const exported = expectDefined(
         parsed.nodeChanges.find((node) => node.name === 'Rescaled owner')
       )
-      const symbol = exported.symbolData as SymbolData
+      const symbol = expectDefined(symbolDataOf(exported), 'exported symbol data')
       const symbolID = expectDefined(symbol.symbolID)
       expect(
         symbol.symbolOverrides?.filter((entry) => entry.size).map((entry) => entry.guidPath?.guids)
diff --git a/packages/core/tests/io/formats/fig/export/self-size-export.test.ts b/packages/core/tests/io/formats/fig/export/self-size-export.test.ts
index b09a28a4e..1552d884a 100644
--- a/packages/core/tests/io/formats/fig/export/self-size-export.test.ts
+++ b/packages/core/tests/io/formats/fig/export/self-size-export.test.ts
@@ -3,7 +3,7 @@ import { expect, test } from 'bun:test'
 import { exportFigFile } from '@open-pencil/core/io'
 import { initCodec } from '@open-pencil/core/kiwi'
 import { parseFigBuffer } from '@open-pencil/fig'
-import type { SymbolData } from '@open-pencil/fig/instance-overrides'
+import { symbolDataOf } from '@open-pencil/fig/instance-overrides'
 import { SceneGraph, setInstanceOverride, rescaleNodeTree } from '@open-pencil/scene-graph'
 
 import { expectDefined } from '#core-tests/helpers/assert'
@@ -25,7 +25,7 @@ test('serializes self size claims against the instance main component', async ()
   const bytes = await exportFigFile(graph)
   const { nodeChanges } = parseFigBuffer(bytes.buffer as ArrayBuffer)
   const exported = nodeChanges.find((node) => node.type === 'INSTANCE')
-  const symbol = exported?.symbolData as SymbolData | undefined
+  const symbol = exported ? symbolDataOf(exported) : undefined
   if (!symbol) throw new Error('Missing exported symbol')
   expect(exported?.size).toEqual({ x: 16, y: 16 })
   expect(symbol.uniformScaleFactor).toBe(0.5)
diff --git a/packages/fig/src/instance-overrides/index.ts b/packages/fig/src/instance-overrides/index.ts
index 9c0726cd1..509257a12 100644
--- a/packages/fig/src/instance-overrides/index.ts
+++ b/packages/fig/src/instance-overrides/index.ts
@@ -10,6 +10,9 @@ export { materializeComponentClosure } from './component-closure'
 export { linkInstanceSourceChildren, mapInstanceSourceChildren } from './source-children'
 export type { MaterializedInstance } from './materialize-instance'
 
+/** The Kiwi codec types only `symbolID`, so the remaining symbol fields are read through these. */
+export { symbolDataOf, symbolOverridesOf } from './types'
+
 export type {
   ComponentPropAssignment,
   ComponentPropDef,
diff --git a/tests/engine/library/discovery.test.ts b/tests/app/libraries/discovery.test.ts
similarity index 100%
rename from tests/engine/library/discovery.test.ts
rename to tests/app/libraries/discovery.test.ts
diff --git a/tests/engine/library/hash-normalization.test.ts b/tests/app/libraries/hash-normalization.test.ts
similarity index 100%
rename from tests/engine/library/hash-normalization.test.ts
rename to tests/app/libraries/hash-normalization.test.ts
diff --git a/tests/engine/library/instance-updates.test.ts b/tests/app/libraries/instance-updates.test.ts
similarity index 100%
rename from tests/engine/library/instance-updates.test.ts
rename to tests/app/libraries/instance-updates.test.ts
diff --git a/tests/engine/library/materialize.test.ts b/tests/app/libraries/materialize.test.ts
similarity index 100%
rename from tests/engine/library/materialize.test.ts
rename to tests/app/libraries/materialize.test.ts
diff --git a/tests/engine/library/metadata.test.ts b/tests/app/libraries/metadata.test.ts
similarity index 100%
rename from tests/engine/library/metadata.test.ts
rename to tests/app/libraries/metadata.test.ts
diff --git a/tests/engine/library/preview.test.ts b/tests/app/libraries/preview.test.ts
similarity index 100%
rename from tests/engine/library/preview.test.ts
rename to tests/app/libraries/preview.test.ts
diff --git a/tests/engine/library/routed-catalog.test.ts b/tests/app/libraries/routed-catalog.test.ts
similarity index 100%
rename from tests/engine/library/routed-catalog.test.ts
rename to tests/app/libraries/routed-catalog.test.ts
diff --git a/tests/engine/library/selective.test.ts b/tests/app/libraries/selective.test.ts
similarity index 100%
rename from tests/engine/library/selective.test.ts
rename to tests/app/libraries/selective.test.ts
diff --git a/tests/engine/library/snapshot.test.ts b/tests/app/libraries/snapshot.test.ts
similarity index 100%
rename from tests/engine/library/snapshot.test.ts
rename to tests/app/libraries/snapshot.test.ts
diff --git a/tests/engine/library/source-publication.test.ts b/tests/app/libraries/source-publication.test.ts
similarity index 100%
rename from tests/engine/library/source-publication.test.ts
rename to tests/app/libraries/source-publication.test.ts
diff --git a/tests/engine/library/storage-catalog.test.ts b/tests/app/libraries/storage-catalog.test.ts
similarity index 100%
rename from tests/engine/library/storage-catalog.test.ts
rename to tests/app/libraries/storage-catalog.test.ts
diff --git a/tests/engine/library/update-groups.test.ts b/tests/app/libraries/update-groups.test.ts
similarity index 100%
rename from tests/engine/library/update-groups.test.ts
rename to tests/app/libraries/update-groups.test.ts
diff --git a/tests/engine/library/update.test.ts b/tests/app/libraries/update.test.ts
similarity index 100%
rename from tests/engine/library/update.test.ts
rename to tests/app/libraries/update.test.ts
diff --git a/tests/helpers/fig/nested-binding.ts b/tests/helpers/fig/nested-binding.ts
index 456091efb..cccff609d 100644
--- a/tests/helpers/fig/nested-binding.ts
+++ b/tests/helpers/fig/nested-binding.ts
@@ -1,4 +1,4 @@
-import type { SymbolData } from '@open-pencil/fig/instance-overrides'
+import { symbolOverridesOf } from '@open-pencil/fig/instance-overrides'
 import type { NodeChange } from '@open-pencil/kiwi/fig/codec'
 
 import fixture from '#tests/fixtures/nested-binding-ownership-records.json' with { type: 'json' }
@@ -11,7 +11,7 @@ export function inheritedNestedBindingRecords(): NodeChange[] {
     changes.find((node) => node.guid?.sessionID === 293733 && node.guid.localID === 8),
     'captured owner'
   )
-  for (const override of (owner.symbolData as SymbolData).symbolOverrides ?? []) {
+  for (const override of symbolOverridesOf(owner)) {
     Reflect.deleteProperty(override, 'parameterConsumptionMap')
   }
   return changes
diff --git a/tools/checks/test-homes/engine-baseline.txt b/tools/checks/test-homes/engine-baseline.txt
index ac7f062bc..0a68597f2 100644
--- a/tools/checks/test-homes/engine-baseline.txt
+++ b/tools/checks/test-homes/engine-baseline.txt
@@ -311,19 +311,6 @@ tests/engine/layout/auto-layout/text/measurement.test.ts
 tests/engine/layout/auto-layout/vertical/basic.test.ts
 tests/engine/layout/auto-layout/wrap/layout.test.ts
 tests/engine/layout/grid-layout.test.ts
-tests/engine/library/discovery.test.ts
-tests/engine/library/hash-normalization.test.ts
-tests/engine/library/instance-updates.test.ts
-tests/engine/library/materialize.test.ts
-tests/engine/library/metadata.test.ts
-tests/engine/library/preview.test.ts
-tests/engine/library/routed-catalog.test.ts
-tests/engine/library/selective.test.ts
-tests/engine/library/snapshot.test.ts
-tests/engine/library/source-publication.test.ts
-tests/engine/library/storage-catalog.test.ts
-tests/engine/library/update-groups.test.ts
-tests/engine/library/update.test.ts
 tests/engine/lint/basic.test.ts
 tests/engine/lint/variable-binding-validation.test.ts
 tests/engine/mcp/auth.test.ts
diff --git a/tools/dev/unit-tests/src/shards.ts b/tools/dev/unit-tests/src/shards.ts
index 2c6d12efc..2f460019b 100644
--- a/tools/dev/unit-tests/src/shards.ts
+++ b/tools/dev/unit-tests/src/shards.ts
@@ -37,7 +37,6 @@ export const UNIT_TEST_GROUPS = {
     'tests/engine/editor',
     'tests/engine/icons',
     'tests/engine/layout',
-    'tests/engine/library',
     'tests/engine/lint',
     'tests/engine/profiler',
     'tests/engine/text',