diff --git a/src/main/services/team/ChangeExtractorService.ts b/src/main/services/team/ChangeExtractorService.ts
index a84d570d..ac1c68d2 100644
--- a/src/main/services/team/ChangeExtractorService.ts
+++ b/src/main/services/team/ChangeExtractorService.ts
@@ -9,7 +9,7 @@ import {
 } from '@shared/utils/taskChangeState';
 import { createHash } from 'crypto';
 import { existsSync } from 'fs';
-import { mkdtemp, readdir, readFile, rm, stat, writeFile } from 'fs/promises';
+import { chmod, mkdtemp, readdir, readFile, rm, stat, writeFile } from 'fs/promises';
 import * as os from 'os';
 import * as path from 'path';
 
@@ -77,6 +77,7 @@ interface OpenCodeBackfillAttempt {
 
 interface OpenCodeDeliveryContextTempFile {
   filePath: string | null;
+  hash: string | null;
   cleanup: () => Promise<void>;
 }
 
@@ -513,7 +514,12 @@ export class ChangeExtractorService {
         workspaceRoot,
         attributionMode: OPEN_CODE_AUTO_BACKFILL_ATTRIBUTION_MODE,
         ...(backfillMemberName ? { memberName: backfillMemberName } : {}),
-        ...(deliveryContext.filePath ? { deliveryContextPath: deliveryContext.filePath } : {}),
+        ...(deliveryContext.filePath
+          ? {
+              deliveryContextPath: deliveryContext.filePath,
+              deliveryContextHash: deliveryContext.hash ?? undefined,
+            }
+          : {}),
       });
       void appendOpenCodeTaskChangeDiag({
         event: 'backfill_result',
@@ -661,27 +667,26 @@ export class ChangeExtractorService {
     records: Awaited<ReturnType<ChangeExtractorService['readOpenCodeDeliveryContextRecords']>>
   ): Promise<OpenCodeDeliveryContextTempFile> {
     if (records.length === 0) {
-      return { filePath: null, cleanup: async () => undefined };
+      return { filePath: null, hash: null, cleanup: async () => undefined };
     }
 
     const dir = await mkdtemp(path.join(os.tmpdir(), 'claude-team-opencode-ledger-context-'));
+    await chmod(dir, 0o700).catch(() => undefined);
     const filePath = path.join(dir, 'delivery-context.json');
-    await writeFile(
-      filePath,
-      `${JSON.stringify(
-        {
-          schemaVersion: 1,
-          teamName,
-          taskId,
-          records,
-        },
-        null,
-        2
-      )}\n`,
-      { encoding: 'utf8', mode: 0o600 }
-    );
+    const rawContext = `${JSON.stringify(
+      {
+        schemaVersion: 1,
+        teamName,
+        taskId,
+        records,
+      },
+      null,
+      2
+    )}\n`;
+    await writeFile(filePath, rawContext, { encoding: 'utf8', mode: 0o600 });
     return {
       filePath,
+      hash: createHash('sha256').update(rawContext).digest('hex'),
       cleanup: async () => {
         await rm(dir, { recursive: true, force: true }).catch(() => undefined);
       },
diff --git a/src/main/services/team/opencode/bridge/OpenCodeBridgeCommandContract.ts b/src/main/services/team/opencode/bridge/OpenCodeBridgeCommandContract.ts
index eca8e93a..9a478e01 100644
--- a/src/main/services/team/opencode/bridge/OpenCodeBridgeCommandContract.ts
+++ b/src/main/services/team/opencode/bridge/OpenCodeBridgeCommandContract.ts
@@ -239,6 +239,7 @@ export interface OpenCodeBackfillTaskLedgerCommandBody {
   projectDir?: string;
   workspaceRoot?: string;
   deliveryContextPath?: string;
+  deliveryContextHash?: string;
   attributionMode?: OpenCodeBackfillTaskLedgerAttributionMode;
   dryRun?: boolean;
 }
diff --git a/test/main/services/team/ChangeExtractorService.test.ts b/test/main/services/team/ChangeExtractorService.test.ts
index 19ca95c6..daaa5428 100644
--- a/test/main/services/team/ChangeExtractorService.test.ts
+++ b/test/main/services/team/ChangeExtractorService.test.ts
@@ -1,5 +1,6 @@
 import * as os from 'os';
 import * as path from 'path';
+import { createHash } from 'crypto';
 import { afterEach, describe, expect, it, vi } from 'vitest';
 
 import * as fs from 'fs/promises';
@@ -999,7 +1000,12 @@ describe('ChangeExtractorService', () => {
     await fs.mkdir(projectPath, { recursive: true });
     await writeOpenCodeDeliveryLedger(tmpDir);
 
+    let deliveryContextHashVerified = false;
     const backfillOpenCodeTaskLedger = vi.fn(async (input: any) => {
+      deliveryContextHashVerified =
+        createHash('sha256')
+          .update(await fs.readFile(input.deliveryContextPath, 'utf8'))
+          .digest('hex') === input.deliveryContextHash;
       await writeOpenCodeLedgerBundle(input.projectDir, projectPath);
       return {
         schemaVersion: 1,
@@ -1069,6 +1075,12 @@ describe('ChangeExtractorService', () => {
         attributionMode: 'strict-delivery',
       })
     );
+    const backfillInput = backfillOpenCodeTaskLedger.mock.calls[0]?.[0];
+    expect(backfillInput.deliveryContextPath).toEqual(
+      expect.stringContaining('delivery-context.json')
+    );
+    expect(backfillInput.deliveryContextHash).toMatch(/^[a-f0-9]{64}$/);
+    expect(deliveryContextHashVerified).toBe(true);
     expect(backfillOpenCodeTaskLedger.mock.calls[0]?.[0]).not.toHaveProperty('evidenceMode');
     expect(workerClient.computeTaskChanges).not.toHaveBeenCalled();
   });
@@ -1513,6 +1525,7 @@ describe('ChangeExtractorService', () => {
           projectDir,
           workspaceRoot: projectPath,
           deliveryContextPath: expect.stringContaining('delivery-context.json'),
+          deliveryContextHash: expect.stringMatching(/^[a-f0-9]{64}$/),
           attributionMode: 'strict-delivery',
         })
       );
@@ -1621,6 +1634,7 @@ describe('ChangeExtractorService', () => {
     expect(backfillOpenCodeTaskLedger.mock.calls[0]?.[0]?.deliveryContextPath).toEqual(
       expect.stringContaining('delivery-context.json')
     );
+    expect(backfillOpenCodeTaskLedger.mock.calls[0]?.[0]?.deliveryContextHash).toMatch(/^[a-f0-9]{64}$/);
   });
 
   it('does not cache negative OpenCode backfill while delivery context already exists', async () => {
@@ -1732,8 +1746,10 @@ describe('ChangeExtractorService', () => {
     expect(backfillOpenCodeTaskLedger.mock.calls[0]?.[0]?.deliveryContextPath).toEqual(
       expect.stringContaining('delivery-context.json')
     );
+    expect(backfillOpenCodeTaskLedger.mock.calls[0]?.[0]?.deliveryContextHash).toMatch(/^[a-f0-9]{64}$/);
     expect(backfillOpenCodeTaskLedger.mock.calls[1]?.[0]?.deliveryContextPath).toEqual(
       expect.stringContaining('delivery-context.json')
     );
+    expect(backfillOpenCodeTaskLedger.mock.calls[1]?.[0]?.deliveryContextHash).toMatch(/^[a-f0-9]{64}$/);
   });
 });
diff --git a/test/main/services/team/OpenCodeReadinessBridge.test.ts b/test/main/services/team/OpenCodeReadinessBridge.test.ts
index 26079377..090a4bd7 100644
--- a/test/main/services/team/OpenCodeReadinessBridge.test.ts
+++ b/test/main/services/team/OpenCodeReadinessBridge.test.ts
@@ -170,6 +170,8 @@ describe('OpenCodeReadinessBridge', () => {
         taskDisplayId: 'abc12345',
         projectDir: '/claude/project',
         workspaceRoot: '/repo',
+        deliveryContextPath: '/tmp/claude-team-opencode-ledger-context-test/delivery-context.json',
+        deliveryContextHash: 'a'.repeat(64),
       })
     ).resolves.toMatchObject({
       outcome: 'imported',
@@ -184,6 +186,8 @@ describe('OpenCodeReadinessBridge', () => {
         taskDisplayId: 'abc12345',
         projectDir: '/claude/project',
         workspaceRoot: '/repo',
+        deliveryContextPath: '/tmp/claude-team-opencode-ledger-context-test/delivery-context.json',
+        deliveryContextHash: 'a'.repeat(64),
       },
       {
         cwd: '/repo',