diff --git a/apps/sim/lib/copilot/tools/handlers/materialize-file.test.ts b/apps/sim/lib/copilot/tools/handlers/materialize-file.test.ts
index 69848850802..65af6a518cb 100644
--- a/apps/sim/lib/copilot/tools/handlers/materialize-file.test.ts
+++ b/apps/sim/lib/copilot/tools/handlers/materialize-file.test.ts
@@ -155,6 +155,9 @@ const STORAGE_CONTEXT = {
   customStorageLimitGB: null,
 }
 
+const POSTGRES_INT4_MAX = 2_147_483_647
+const OVERSIZED_BYTES = 3 * 1024 * 1024 * 1024
+
 const mothershipRow = {
   id: 'file-1',
   key: 'mothership/file-1',
@@ -339,6 +342,58 @@ describe('executeMaterializeFile - save storage transition', () => {
     )
   })
 
+  it('writes an int4-representable legacy size and the exact byte count above the int4 ceiling', async () => {
+    // A row above the int4 ceiling must not be written raw to `size`: Postgres
+    // raises 22003 and the save becomes unrecoverable.
+    mockHeadObject.mockResolvedValue({ size: OVERSIZED_BYTES, contentType: 'text/plain' })
+
+    const result = await executeMaterializeFile(
+      { fileNames: ['report.txt'], operation: 'save' },
+      context
+    )
+
+    expect(result.success).toBe(true)
+    const [updateSet] = dbChainMockFns.set.mock.calls.at(-1) as [Record<string, unknown>]
+    expect(updateSet.size).toBe(POSTGRES_INT4_MAX)
+    expect(updateSet.sizeBytes).toBe(OVERSIZED_BYTES)
+    expect(mockCheckStorageQuotaForBillingContext).toHaveBeenCalledWith(
+      STORAGE_CONTEXT,
+      OVERSIZED_BYTES
+    )
+    expect(mockIncrementStorageUsageForBillingContextInTx).toHaveBeenCalledWith(
+      expect.anything(),
+      STORAGE_CONTEXT,
+      OVERSIZED_BYTES
+    )
+  })
+
+  it('falls back to the exact stored byte count, not the clamped legacy size', async () => {
+    // Without cloud storage a missing object does not short-circuit, so the row is
+    // the only size source — and its `size` is already clamped.
+    mockHeadObject.mockResolvedValue(null)
+    mockHasCloudStorage.mockReturnValue(false)
+    mockFindUpload.mockResolvedValue({
+      ...mothershipRow,
+      size: POSTGRES_INT4_MAX,
+      sizeBytes: OVERSIZED_BYTES,
+    })
+
+    const result = await executeMaterializeFile(
+      { fileNames: ['report.txt'], operation: 'save' },
+      context
+    )
+
+    expect(result.success).toBe(true)
+    const [updateSet] = dbChainMockFns.set.mock.calls.at(-1) as [Record<string, unknown>]
+    expect(updateSet.sizeBytes).toBe(OVERSIZED_BYTES)
+    expect(updateSet.size).toBe(POSTGRES_INT4_MAX)
+    expect(mockIncrementStorageUsageForBillingContextInTx).toHaveBeenCalledWith(
+      expect.anything(),
+      STORAGE_CONTEXT,
+      OVERSIZED_BYTES
+    )
+  })
+
   it('materializes with an available root-level copy name', async () => {
     mockFindUpload.mockResolvedValueOnce({
       ...mothershipRow,
diff --git a/apps/sim/lib/copilot/tools/handlers/materialize-file.ts b/apps/sim/lib/copilot/tools/handlers/materialize-file.ts
index 25dc2a51685..d6b5e2dece6 100644
--- a/apps/sim/lib/copilot/tools/handlers/materialize-file.ts
+++ b/apps/sim/lib/copilot/tools/handlers/materialize-file.ts
@@ -36,6 +36,7 @@ import {
 } from '@/lib/uploads/contexts/workspace/workspace-file-manager'
 import { getBoundWorkspaceFileSecretProvenance } from '@/lib/uploads/contexts/workspace/workspace-file-secret-provenance'
 import { hasCloudStorage, headObject } from '@/lib/uploads/core/storage-service'
+import { toLegacyWorkspaceFileSize } from '@/lib/uploads/shared/types'
 import { isArchiveFileName } from '@/lib/uploads/utils/file-utils'
 import { parseWorkflowJson } from '@/lib/workflows/operations/import-export'
 import { saveWorkflowToNormalizedTables } from '@/lib/workflows/persistence/utils'
@@ -109,7 +110,12 @@ async function executeSave(
   if (!head && hasCloudStorage()) {
     return { success: false, error: `Upload object not found: "${fileName}".` }
   }
-  const verifiedSize = head?.size ?? row.size
+  /**
+   * The true byte count can exceed the legacy int4 `size` column, so read the exact
+   * `sizeBytes` first and clamp back down for the legacy projection.
+   */
+  const verifiedSize = head?.size ?? row.sizeBytes ?? row.size
+  const legacySize = toLegacyWorkspaceFileSize(verifiedSize)
   const billingContext = await resolveStorageBillingContext(workspaceId)
   const quotaCheck = await checkStorageQuotaForBillingContext(billingContext, verifiedSize)
   if (!quotaCheck.allowed) {
@@ -145,7 +151,8 @@ async function executeSave(
             messageId: null,
             originalName: materializedName,
             displayName: materializedName,
-            size: verifiedSize,
+            size: legacySize,
+            sizeBytes: verifiedSize,
           })
           .where(
             and(