diff --git a/src/lib/purchasing/delivery-posting.test.ts b/src/lib/purchasing/delivery-posting.test.ts
index e09587a..f72492a 100644
--- a/src/lib/purchasing/delivery-posting.test.ts
+++ b/src/lib/purchasing/delivery-posting.test.ts
@@ -27,7 +27,7 @@ it('posts every planned line, closes NIL lines and journals the result',async()=
  expect(post).toHaveBeenCalledTimes(2);
  expect(post.mock.calls[1][1].body.confirmation).toMatchObject({disposition:'not_delivered'});
  expect(r.result).toMatchObject({complete:true});
- expect([...store('mcp_operations').values()][0]).toMatchObject({status:'committed',tool:'post_delivery'});
+ expect([...store('mcp_operations').values()][0]).toMatchObject({status:'committed',tool:'post_delivery',payload_hash:expect.stringMatching(/^[a-f0-9]{64}$/)});
 });
 it('refuses before posting when a delivered line is not planned',async()=>{
  const {ctx}=await setup([alloc([0]),alloc([1])],[5,3]);
diff --git a/src/lib/purchasing/delivery-posting.ts b/src/lib/purchasing/delivery-posting.ts
index 1ecd940..35d1dd1 100644
--- a/src/lib/purchasing/delivery-posting.ts
+++ b/src/lib/purchasing/delivery-posting.ts
@@ -16,7 +16,7 @@
  */
 import {z} from 'zod';
 import type {PurchasingContext,OperationResult} from './types';
-import {MutationSchema,operationRecordId} from './operations';
+import {MutationSchema,operationPayloadHash,operationRecordId} from './operations';
 import {RecordId} from './documents';
 import {PurchasingError,describePurchasingError} from './errors';
 import {withResourceLease} from './resource-lease';
@@ -39,7 +39,7 @@ export async function postDelivery(ctx:PurchasingContext,input:Record<string,unk
  const journalId=operationRecordId(ctx.principal.id,'post_delivery',args.operationId);
  const prior=await ctx.pb.collection('mcp_operations').getOne(journalId).catch(()=>null);
  if(prior?.status==='committed')return {operationId:args.operationId,status:'committed',result:(prior.result??null) as Record<string,unknown>|null};
- if(!prior)await ctx.pb.collection('mcp_operations').create({id:journalId,credential:ctx.principal.id,tool:'post_delivery',operation_id:args.operationId,status:'pending'});
+ if(!prior)await ctx.pb.collection('mcp_operations').create({id:journalId,credential:ctx.principal.id,tool:'post_delivery',operation_id:args.operationId,payload_hash:operationPayloadHash('post_delivery',args),status:'pending'});
  const note=await ctx.pb.collection('dn_batch_notes').getOne(args.id);
  if(note.batch!==args.batchId)throw new PurchasingError('candidate_batch_mismatch');
  if(!note.purchase_order||!note.supplier)throw new PurchasingError('candidate_entities_unresolved',409);