diff --git a/packages/orchestration/test/test-withdraw-reward.js b/packages/orchestration/test/test-withdraw-reward.js
index 1fce513f570..f58d3fef533 100644
--- a/packages/orchestration/test/test-withdraw-reward.js
+++ b/packages/orchestration/test/test-withdraw-reward.js
@@ -1,7 +1,7 @@
 // @ts-check
 import { test as anyTest } from '@agoric/zoe/tools/prepare-test-env-ava.js';
 
-import { encodeBase64 } from '@endo/base64';
+import { decodeBase64, encodeBase64 } from '@endo/base64';
 import { E, Far } from '@endo/far';
 import * as pbjs from 'protobufjs';
 import {
@@ -9,6 +9,8 @@ import {
   MsgWithdrawDelegatorRewardResponse,
 } from '@agoric/cosmic-proto/cosmos/distribution/v1beta1/tx.js';
 import { makeScalarBigMapStore } from '@agoric/vat-data';
+import { MsgDelegateResponse } from '@agoric/cosmic-proto/cosmos/staking/v1beta1/tx';
+import { Any } from '@agoric/cosmic-proto/google/protobuf/any';
 import { prepareStakingAccountKit } from '../src/exos/stakingAccountKit.js';
 
 /** @import {ChainAccount} from '../src/types.js'; */
@@ -21,6 +23,32 @@ const { Fail } = assert;
 /** @type {typeof import('protobufjs').Writer} */
 const Writer = pbjs.default.Writer;
 
+const scenario1 = {
+  acct1: {
+    address: 'agoric1spy36ltduehs5dmszfrp792f0k2emcntrql3nx',
+  },
+  validator: { address: 'agoric1valoper234', addressEncoding: 'bech32' },
+  delegations: {
+    agoric1valoper234: { denom: 'ustake', amount: '200' },
+  },
+};
+
+test('DelegateResponse decoding', t => {
+  // executeEncodedTx() returns "acknowledge string"
+  const ackStr =
+    'Ei0KKy9jb3Ntb3Muc3Rha2luZy52MWJldGExLk1zZ0RlbGVnYXRlUmVzcG9uc2U=';
+  // That's base64 protobuf of an Any
+  const any = Any.decode(decodeBase64(ackStr));
+
+  // use toJSON to get a ProtoMsg
+  // we happen to know that it's a MsgDelegateResponseProtoMsg
+  /** @import {MsgDelegateResponseProtoMsg} from '@agoric/cosmic-proto/cosmos/staking/v1beta1/tx.js'; */
+  const msgA = /** @type {MsgDelegateResponseProtoMsg} */ (Any.toJSON(any));
+  // now use fromProtoMsg to get a MsgDelegateResponse
+  const msgD = MsgDelegateResponse.fromProtoMsg(msgA);
+  t.deepEqual(msgD, {});
+});
+
 test('MsgWithdrawDelegatorReward: protobuf encoding reminder', t => {
   const actual = MsgWithdrawDelegatorReward.toProtoMsg({
     delegatorAddress: 'abc',
@@ -49,23 +77,33 @@ test('MsgWithdrawDelegatorReward: protobuf encoding reminder', t => {
 const mockAccount = (addr = 'agoric1234', delegations = {}) => {
   const calls = [];
 
-  const typeUrl = '/cosmos.distribution.v1beta1.MsgWithdrawDelegatorReward';
+  const simulate = {
+    '/cosmos.distribution.v1beta1.MsgWithdrawDelegatorReward': _m => {
+      const response = { amount: Object.values(delegations) };
+      const bytes =
+        MsgWithdrawDelegatorRewardResponse.encode(response).finish();
+      const ackStr = encodeBase64(bytes);
+      return ackStr;
+    },
+
+    '/cosmos.staking.v1beta1.MsgDelegate': _m => {
+      return 'Ei0KKy9jb3Ntb3Muc3Rha2luZy52MWJldGExLk1zZ0RlbGVnYXRlUmVzcG9uc2U=';
+      //   const m2 = Any.fromJSON(MsgDelegateResponse.toProtoMsg({}));
+      //   return encodeBase64(Any.encode(m2).finish());
+    },
+  };
 
   /** @type {ChainAccount} */
   const account = Far('MockAccount', {
     getAccountAddress: () => addr,
     executeEncodedTx: async msgs => {
       assert.equal(msgs.length, 1);
-      assert.equal(msgs[0].typeUrl, typeUrl);
+      const { typeUrl } = msgs[0];
+      const doMessage = simulate[typeUrl];
+      assert(doMessage, `unknown ${typeUrl}`);
       await null;
       calls.push({ msgs });
-      const wr = new Writer();
-      for (const v of Object.values(delegations)) {
-        // @ts-expect-error BinaryWriter is not exported
-        MsgWithdrawDelegatorRewardResponse.encode({ amount: [v] }, wr);
-      }
-      const bs = wr.finish();
-      return encodeBase64(bs);
+      return doMessage(msgs[0]);
     },
     executeTx: () => Fail`mock`,
     close: () => Fail`mock`,
@@ -76,52 +114,101 @@ const mockAccount = (addr = 'agoric1234', delegations = {}) => {
   return { account, calls };
 };
 
-/** @returns {ZCF} */
-const mockZCF = () =>
-  harden({
+const mockZCF = () => {
+  const toHandler = new Map();
+  /** @type {ZCF} */
+  const zcf = harden({
     // @ts-expect-error mock
     makeInvitation: async (handler, desc, c = undefined, patt = undefined) => {
-      //   const userSeat = harden({
-      //     getOfferResult: () => {
-      //       const zcfSeat = {};
-      //       const r = handler(zcfSeat);
-      //       return r;
-      //     },
-      //   });
       /** @type {Invitation} */
       // @ts-expect-error mock
       const invitation = harden({});
+      toHandler.set(invitation, handler);
       return invitation;
     },
   });
+  const zoe = harden({
+    offer(invitation) {
+      const handler = toHandler.get(invitation);
+      const zcfSeat = harden({
+        exit() {},
+      });
+      const result = Promise.resolve(null).then(() => handler(zcfSeat));
+      const userSeat = harden({
+        getOfferResult: () => result,
+      });
+      return userSeat;
+    },
+  });
+  return { zcf, zoe };
+};
+
+const makeRecorderKit = () => {
+  /** @type {any} */
+  const kit = harden({});
+  return kit;
+};
 
 test('withdraw rewards from staking account holder', async t => {
-  const makeRecorderKit = () => {
-    /** @type {any} */
-    const kit = harden({});
-    return kit;
-  };
   const baggage = makeScalarBigMapStore('b1');
-  const zcf = mockZCF();
+  const { zcf } = mockZCF();
   const make = prepareStakingAccountKit(baggage, makeRecorderKit, zcf);
 
-  const validator = { address: 'agoric1valoper234', addressEncoding: 'bech32' };
-  const delegations = {
-    [validator.address]: { denom: 'ustake', amount: '200' },
-  };
+  const { validator, delegations } = scenario1;
+
   const { account } = mockAccount(undefined, delegations);
   //   const { rootNode } = makeFakeStorageKit('mockChainStorageRoot');
   /** @type {StorageNode} */
   // @ts-expect-error mock
   const storageNode = Far('StorageNode', {});
-  const addr = 'agoric123';
 
   // TODO: invitationMakers
-  const { helper } = make(account, storageNode, addr);
+  const { helper } = make(account, storageNode, account.getAccountAddress());
   const actual = await E(helper).withdrawReward(validator);
   t.deepEqual(actual, [{ denom: 'ustake', value: 200n }]);
 });
 
+test(`delegate; undelegate`, async t => {
+  const baggage = makeScalarBigMapStore('b1');
+  const { zcf, zoe } = mockZCF();
+  const make = prepareStakingAccountKit(baggage, makeRecorderKit, zcf);
+
+  const { validator, delegations } = scenario1;
+
+  const { account } = mockAccount(undefined, delegations);
+  /** @type {StorageNode} */
+  // @ts-expect-error mock
+  const storageNode = Far('StorageNode', {});
+
+  // TODO: invitationMakers
+  const { invitationMakers } = make(
+    account,
+    storageNode,
+    account.getAccountAddress(),
+  );
+
+  const toDelegate = await E(invitationMakers).Delegate(validator.address, {
+    brand: Far('Token'),
+    value: 2n,
+  });
+  {
+    const seat = E(zoe).offer(toDelegate);
+    const result = await E(seat).getOfferResult();
+
+    t.deepEqual(result, {});
+  }
+
+  const toWithdraw = await E(invitationMakers).WithdrawReward(
+    validator.address,
+  );
+  {
+    const seat = E(zoe).offer(toWithdraw);
+    const result = await E(seat).getOfferResult();
+
+    t.deepEqual(result, [{ denom: 'ustake', value: 200n }]);
+  }
+});
+
 test.todo(`delegate; undelegate; collect rewards`);
 test.todo('undelegate uses a timer: begin; how long? wait; resolve');
 test.todo('undelegate is cancellable - cosmos cancelUnbonding');