diff --git a/.github/workflows/test-all-packages.yml b/.github/workflows/test-all-packages.yml
index 50fa4af159de..33558a16e9a1 100644
--- a/.github/workflows/test-all-packages.yml
+++ b/.github/workflows/test-all-packages.yml
@@ -217,6 +217,9 @@ jobs:
       - name: yarn test (internal)
         if: (success() || failure())
         run: cd packages/internal && yarn ${{ steps.vars.outputs.test }} | $TEST_COLLECT
+      - name: yarn test (kmarshal)
+        if: (success() || failure())
+        run: cd packages/kmarshal && yarn ${{ steps.vars.outputs.test }} | $TEST_COLLECT
       - name: yarn test (network)
         if: (success() || failure())
         run: cd packages/network && yarn ${{ steps.vars.outputs.test }} | $TEST_COLLECT
diff --git a/packages/SwingSet/package.json b/packages/SwingSet/package.json
index a375d8f2ad46..ce15fac215f5 100644
--- a/packages/SwingSet/package.json
+++ b/packages/SwingSet/package.json
@@ -29,6 +29,7 @@
   "dependencies": {
     "@agoric/assert": "^0.6.0",
     "@agoric/internal": "^0.3.2",
+    "@agoric/kmarshal": "^0.1.0",
     "@agoric/store": "^0.9.2",
     "@agoric/swing-store": "^0.9.1",
     "@agoric/swingset-liveslots": "^0.10.2",
diff --git a/packages/SwingSet/src/controller/controller.js b/packages/SwingSet/src/controller/controller.js
index 880b0e9bb65c..58661fcab813 100644
--- a/packages/SwingSet/src/controller/controller.js
+++ b/packages/SwingSet/src/controller/controller.js
@@ -20,7 +20,7 @@ import engineGC from '@agoric/internal/src/lib-nodejs/engine-gc.js';
 import { startSubprocessWorker } from '@agoric/internal/src/lib-nodejs/spawnSubprocessWorker.js';
 import { waitUntilQuiescent } from '@agoric/internal/src/lib-nodejs/waitUntilQuiescent.js';
 import { makeGcAndFinalize } from '@agoric/internal/src/lib-nodejs/gc-and-finalize.js';
-import { kslot, krefOf } from '../lib/kmarshal.js';
+import { kslot, krefOf } from '@agoric/kmarshal';
 import { insistStorageAPI } from '../lib/storageAPI.js';
 import {
   buildKernelBundle,
diff --git a/packages/SwingSet/src/controller/initializeKernel.js b/packages/SwingSet/src/controller/initializeKernel.js
index 233901e40154..dbf4a74cf10a 100644
--- a/packages/SwingSet/src/controller/initializeKernel.js
+++ b/packages/SwingSet/src/controller/initializeKernel.js
@@ -3,9 +3,9 @@
 import { makeMarshal } from '@endo/marshal';
 import { Far } from '@endo/far';
 import { assert, Fail } from '@agoric/assert';
+import { kser, kunser } from '@agoric/kmarshal';
 import { assertKnownOptions } from '../lib/assertOptions.js';
 import { insistVatID } from '../lib/id.js';
-import { kser, kunser } from '../lib/kmarshal.js';
 import { makeVatSlot } from '../lib/parseVatSlots.js';
 import { insistStorageAPI } from '../lib/storageAPI.js';
 import { makeVatOptionRecorder } from '../lib/recordVatOptions.js';
diff --git a/packages/SwingSet/src/devices/vat-admin/device-vat-admin.js b/packages/SwingSet/src/devices/vat-admin/device-vat-admin.js
index 5edac1d0a97f..59e9d583852d 100644
--- a/packages/SwingSet/src/devices/vat-admin/device-vat-admin.js
+++ b/packages/SwingSet/src/devices/vat-admin/device-vat-admin.js
@@ -1,8 +1,8 @@
 import { Nat } from '@endo/nat';
 import { assert } from '@agoric/assert';
+import { kunser } from '@agoric/kmarshal';
 import { buildSerializationTools } from '../lib/deviceTools.js';
 import { insistVatID } from '../../lib/id.js';
-import { kunser } from '../../lib/kmarshal.js';
 
 /*
 
diff --git a/packages/SwingSet/src/kernel/kernel.js b/packages/SwingSet/src/kernel/kernel.js
index c99e95d0d75c..10df109655bb 100644
--- a/packages/SwingSet/src/kernel/kernel.js
+++ b/packages/SwingSet/src/kernel/kernel.js
@@ -2,9 +2,9 @@ import { assert, Fail } from '@agoric/assert';
 import { isNat } from '@endo/nat';
 import { importBundle } from '@endo/import-bundle';
 import { makeUpgradeDisconnection } from '@agoric/internal/src/upgrade-api.js';
+import { kser, kslot, makeError } from '@agoric/kmarshal';
 import { assertKnownOptions } from '../lib/assertOptions.js';
 import { foreverPolicy } from '../lib/runPolicies.js';
-import { kser, kslot, makeError } from '../lib/kmarshal.js';
 import { makeVatManagerFactory } from './vat-loader/manager-factory.js';
 import { makeVatWarehouse } from './vat-warehouse.js';
 import makeDeviceManager from './deviceManager.js';
diff --git a/packages/SwingSet/src/kernel/kernelQueue.js b/packages/SwingSet/src/kernel/kernelQueue.js
index 471b7cd02936..be025b87b57f 100644
--- a/packages/SwingSet/src/kernel/kernelQueue.js
+++ b/packages/SwingSet/src/kernel/kernelQueue.js
@@ -1,8 +1,8 @@
+import { kser } from '@agoric/kmarshal';
 import { insistKernelType, parseKernelSlot } from './parseKernelSlots.js';
 import { insistCapData } from '../lib/capdata.js';
 import { insistMessage } from '../lib/message.js';
 import { insistVatID } from '../lib/id.js';
-import { kser } from '../lib/kmarshal.js';
 
 /**
  * @param {object} tools
diff --git a/packages/SwingSet/src/kernel/notifyTermination.js b/packages/SwingSet/src/kernel/notifyTermination.js
index cde53fc706b8..38e9d67ce479 100644
--- a/packages/SwingSet/src/kernel/notifyTermination.js
+++ b/packages/SwingSet/src/kernel/notifyTermination.js
@@ -1,5 +1,5 @@
+import { kunser } from '@agoric/kmarshal';
 import { insistCapData } from '../lib/capdata.js';
-import { kunser } from '../lib/kmarshal.js';
 
 /**
  * @param {string} vatID
diff --git a/packages/SwingSet/src/kernel/vat-admin-hooks.js b/packages/SwingSet/src/kernel/vat-admin-hooks.js
index c441bc80af0e..35045111b0f6 100644
--- a/packages/SwingSet/src/kernel/vat-admin-hooks.js
+++ b/packages/SwingSet/src/kernel/vat-admin-hooks.js
@@ -1,6 +1,6 @@
 import { assert } from '@agoric/assert';
+import { kser, kunser } from '@agoric/kmarshal';
 import { insistVatID } from '../lib/id.js';
-import { kser, kunser } from '../lib/kmarshal.js';
 
 export function makeVatAdminHooks(tools) {
   const { kernelKeeper, terminateVat } = tools;
diff --git a/packages/SwingSet/src/lib/capdata.js b/packages/SwingSet/src/lib/capdata.js
index f0e76e701d05..bbbfbbbf6217 100644
--- a/packages/SwingSet/src/lib/capdata.js
+++ b/packages/SwingSet/src/lib/capdata.js
@@ -1,6 +1,6 @@
 import { Fail } from '@agoric/assert';
 import { passStyleOf } from '@endo/far';
-import { kunser, krefOf } from './kmarshal.js';
+import { kunser, krefOf } from '@agoric/kmarshal';
 
 /* eslint-disable jsdoc/require-returns-check */
 /**
diff --git a/packages/SwingSet/src/lib/makeUndeliverableError.js b/packages/SwingSet/src/lib/makeUndeliverableError.js
index 51521e631915..ce9dcec410df 100644
--- a/packages/SwingSet/src/lib/makeUndeliverableError.js
+++ b/packages/SwingSet/src/lib/makeUndeliverableError.js
@@ -11,7 +11,7 @@
 // "data is not callable" error is kind of unique to the way swingset handles
 // references, so we create a distinct error message.
 
-import { kunser, kser } from './kmarshal.js';
+import { kunser, kser } from '@agoric/kmarshal';
 
 export function makeUndeliverableError(methargs) {
   const method = kunser(methargs)[0];
diff --git a/packages/SwingSet/src/vats/comms/controller.js b/packages/SwingSet/src/vats/comms/controller.js
index db0b737285f5..e914c742d7bf 100644
--- a/packages/SwingSet/src/vats/comms/controller.js
+++ b/packages/SwingSet/src/vats/comms/controller.js
@@ -1,6 +1,6 @@
 import { Nat } from '@endo/nat';
 import { assert, Fail } from '@agoric/assert';
-import { kser, kunser, kslot, krefOf } from '../../lib/kmarshal.js';
+import { kser, kunser, kslot, krefOf } from '@agoric/kmarshal';
 
 // deliverToController() is used for local vats which want to talk to us as a
 // vat, rather than as a conduit to talk to remote vats. The bootstrap
diff --git a/packages/SwingSet/src/vats/comms/delivery.js b/packages/SwingSet/src/vats/comms/delivery.js
index 13ec3ffcd958..b8b624e5d2a4 100644
--- a/packages/SwingSet/src/vats/comms/delivery.js
+++ b/packages/SwingSet/src/vats/comms/delivery.js
@@ -1,12 +1,12 @@
 /* eslint-disable no-use-before-define */
 
 import { assert, Fail } from '@agoric/assert';
+import { kser } from '@agoric/kmarshal';
 import { parseLocalSlot, insistLocalType } from './parseLocalSlots.js';
 import { makeUndeliverableError } from '../../lib/makeUndeliverableError.js';
 import { extractSingleSlot, insistCapData } from '../../lib/capdata.js';
 import { insistRemoteType } from './parseRemoteSlot.js';
 import { insistRemoteID } from './remote.js';
-import { kser } from '../../lib/kmarshal.js';
 
 export function makeDeliveryKit(
   state,
diff --git a/packages/SwingSet/src/vats/comms/dispatch.js b/packages/SwingSet/src/vats/comms/dispatch.js
index 9f7e5799170b..5480dabc5cee 100644
--- a/packages/SwingSet/src/vats/comms/dispatch.js
+++ b/packages/SwingSet/src/vats/comms/dispatch.js
@@ -1,10 +1,10 @@
 import { assert, Fail } from '@agoric/assert';
+import { kser, kunser } from '@agoric/kmarshal';
 import { makeVatSlot } from '../../lib/parseVatSlots.js';
 import { insistMessage } from '../../lib/message.js';
 import { makeState } from './state.js';
 import { deliverToController } from './controller.js';
 import { insistCapData } from '../../lib/capdata.js';
-import { kser, kunser } from '../../lib/kmarshal.js';
 
 import { makeCListKit } from './clist.js';
 import { makeDeliveryKit } from './delivery.js';
diff --git a/packages/SwingSet/test/bundling/test-bundles.js b/packages/SwingSet/test/bundling/test-bundles.js
index 137ce9b8a0d0..c3c3d85b495f 100644
--- a/packages/SwingSet/test/bundling/test-bundles.js
+++ b/packages/SwingSet/test/bundling/test-bundles.js
@@ -2,13 +2,12 @@
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import fs from 'fs';
 import bundleSource from '@endo/bundle-source';
 import { assert } from '@agoric/assert';
+import { kunser, krefOf } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { initializeSwingset, makeSwingsetController } from '../../src/index.js';
-import { kunser, krefOf } from '../../src/lib/kmarshal.js';
 
 function bfile(name) {
   return new URL(name, import.meta.url).pathname;
diff --git a/packages/SwingSet/test/change-parameters/test-change-parameters.js b/packages/SwingSet/test/change-parameters/test-change-parameters.js
index 48e22fc24ff5..290cba11ca13 100644
--- a/packages/SwingSet/test/change-parameters/test-change-parameters.js
+++ b/packages/SwingSet/test/change-parameters/test-change-parameters.js
@@ -2,11 +2,10 @@
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import { assert } from '@agoric/assert';
+import { kunser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { initializeSwingset, makeSwingsetController } from '../../src/index.js';
-import { kunser } from '../../src/lib/kmarshal.js';
 
 function bfile(name) {
   return new URL(name, import.meta.url).pathname;
diff --git a/packages/SwingSet/test/commsVatDriver.js b/packages/SwingSet/test/commsVatDriver.js
index 9eb9a7d4e7fc..8e5ffdadc258 100644
--- a/packages/SwingSet/test/commsVatDriver.js
+++ b/packages/SwingSet/test/commsVatDriver.js
@@ -1,10 +1,10 @@
 // @ts-nocheck
 import { assert, Fail } from '@agoric/assert';
+import { kslot, kser } from '@agoric/kmarshal';
 import buildCommsDispatch from '../src/vats/comms/index.js';
 import { debugState } from '../src/vats/comms/dispatch.js';
 import { flipRemoteSlot } from '../src/vats/comms/parseRemoteSlot.js';
 import { makeMessage, makeResolutions } from './util.js';
-import { kslot, kser } from '../src/lib/kmarshal.js';
 
 // This module provides a power tool for testing the comms vat implementation.
 // It provides support for injecting events into the comms vat and observing
diff --git a/packages/SwingSet/test/definition/test-vat-definition.js b/packages/SwingSet/test/definition/test-vat-definition.js
index 0fa550eee2c9..dbd266b2de3b 100644
--- a/packages/SwingSet/test/definition/test-vat-definition.js
+++ b/packages/SwingSet/test/definition/test-vat-definition.js
@@ -1,7 +1,8 @@
 import { test } from '../../tools/prepare-test-env-ava.js';
 
+// eslint-disable-next-line import/order
+import { kser } from '@agoric/kmarshal';
 import { buildVatController } from '../../src/index.js';
-import { kser } from '../../src/lib/kmarshal.js';
 
 test('create with setup and buildRootObject', async t => {
   const config = {
diff --git a/packages/SwingSet/test/device-hooks/test-device-hooks.js b/packages/SwingSet/test/device-hooks/test-device-hooks.js
index 3c4243e34e61..d2521cf698c4 100644
--- a/packages/SwingSet/test/device-hooks/test-device-hooks.js
+++ b/packages/SwingSet/test/device-hooks/test-device-hooks.js
@@ -2,8 +2,8 @@
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import bundleSource from '@endo/bundle-source';
+import { kunser, kser, kslot } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 
 import {
@@ -11,7 +11,6 @@ import {
   makeSwingsetController,
   buildKernelBundles,
 } from '../../src/index.js';
-import { kunser, kser, kslot } from '../../src/lib/kmarshal.js';
 
 function dfile(name) {
   return new URL(`./${name}`, import.meta.url).pathname;
diff --git a/packages/SwingSet/test/device-mailbox/test-device-mailbox.js b/packages/SwingSet/test/device-mailbox/test-device-mailbox.js
index a15f569724af..c7091d638247 100644
--- a/packages/SwingSet/test/device-mailbox/test-device-mailbox.js
+++ b/packages/SwingSet/test/device-mailbox/test-device-mailbox.js
@@ -1,9 +1,9 @@
 // @ts-nocheck
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
-// eslint-disable-next-line import/order
-import bundleSource from '@endo/bundle-source';
 
+import bundleSource from '@endo/bundle-source';
+import { kunser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import {
   initializeSwingset,
@@ -15,7 +15,6 @@ import {
   buildMailbox,
 } from '../../src/devices/mailbox/mailbox.js';
 import { bundleOpts } from '../util.js';
-import { kunser } from '../../src/lib/kmarshal.js';
 
 test.before(async t => {
   const kernelBundles = await buildKernelBundles();
diff --git a/packages/SwingSet/test/devices/bootstrap-1.js b/packages/SwingSet/test/devices/bootstrap-1.js
index f0ea62a34406..058b5c6b6f44 100644
--- a/packages/SwingSet/test/devices/bootstrap-1.js
+++ b/packages/SwingSet/test/devices/bootstrap-1.js
@@ -1,6 +1,6 @@
 import { Fail } from '@agoric/assert';
+import { kser, kunser, krefOf } from '@agoric/kmarshal';
 import { extractMessage } from '../vat-util.js';
-import { kser, kunser, krefOf } from '../../src/lib/kmarshal.js';
 
 export default function setup(syscall, state, _helpers, vatPowers) {
   const { testLog } = vatPowers;
diff --git a/packages/SwingSet/test/devices/bootstrap-4.js b/packages/SwingSet/test/devices/bootstrap-4.js
index ad7150017c70..26111b604318 100644
--- a/packages/SwingSet/test/devices/bootstrap-4.js
+++ b/packages/SwingSet/test/devices/bootstrap-4.js
@@ -1,6 +1,6 @@
+import { kunser, kser, kslot, krefOf } from '@agoric/kmarshal';
 import { insistVatType } from '../../src/lib/parseVatSlots.js';
 import { extractMessage } from '../vat-util.js';
-import { kunser, kser, kslot, krefOf } from '../../src/lib/kmarshal.js';
 
 // to exercise the error we get when syscall.callNow() is given a promise
 // identifier, we must bypass liveslots, which would otherwise protect us
diff --git a/packages/SwingSet/test/devices/test-devices.js b/packages/SwingSet/test/devices/test-devices.js
index 02bbc3ec2d95..7aa66d590db9 100644
--- a/packages/SwingSet/test/devices/test-devices.js
+++ b/packages/SwingSet/test/devices/test-devices.js
@@ -3,8 +3,9 @@
 import { test } from '../../tools/prepare-test-env-ava.js';
 
 import bundleSource from '@endo/bundle-source';
-import { initSwingStore } from '@agoric/swing-store';
 import { parse } from '@endo/marshal';
+import { kser, kslot } from '@agoric/kmarshal';
+import { initSwingStore } from '@agoric/swing-store';
 
 import {
   initializeSwingset,
@@ -13,7 +14,6 @@ import {
 } from '../../src/index.js';
 import buildCommand from '../../src/devices/command/command.js';
 import { bundleOpts, vstr } from '../util.js';
-import { kser, kslot } from '../../src/lib/kmarshal.js';
 
 function dfile(name) {
   return new URL(`./${name}`, import.meta.url).pathname;
diff --git a/packages/SwingSet/test/devices/test-raw-device.js b/packages/SwingSet/test/devices/test-raw-device.js
index 9e79e4c3e3e9..75cfa8f649bc 100644
--- a/packages/SwingSet/test/devices/test-raw-device.js
+++ b/packages/SwingSet/test/devices/test-raw-device.js
@@ -5,7 +5,7 @@ import { test } from '../../tools/prepare-test-env-ava.js';
 // eslint-disable-next-line import/order
 import bundleSource from '@endo/bundle-source';
 import { initSwingStore } from '@agoric/swing-store';
-import { kunser } from '../../src/lib/kmarshal.js';
+import { kunser } from '@agoric/kmarshal';
 
 import {
   initializeSwingset,
diff --git a/packages/SwingSet/test/metering/test-dynamic-vat-metered.js b/packages/SwingSet/test/metering/test-dynamic-vat-metered.js
index 3839c5f94c18..e3157b3f19b7 100644
--- a/packages/SwingSet/test/metering/test-dynamic-vat-metered.js
+++ b/packages/SwingSet/test/metering/test-dynamic-vat-metered.js
@@ -2,12 +2,11 @@
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import bundleSource from '@endo/bundle-source';
+import { kunser, krefOf } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { buildKernelBundles, buildVatController } from '../../src/index.js';
 import { restartVatAdminVat } from '../util.js';
-import { kunser, krefOf } from '../../src/lib/kmarshal.js';
 import { enumeratePrefixedKeys } from '../../src/kernel/state/storageHelper.js';
 
 async function prepare() {
diff --git a/packages/SwingSet/test/metering/test-dynamic-vat-unmetered.js b/packages/SwingSet/test/metering/test-dynamic-vat-unmetered.js
index 42e3f96bee41..d4b759ee3853 100644
--- a/packages/SwingSet/test/metering/test-dynamic-vat-unmetered.js
+++ b/packages/SwingSet/test/metering/test-dynamic-vat-unmetered.js
@@ -1,9 +1,8 @@
-// eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
 // eslint-disable-next-line import/order
+import { kunser } from '@agoric/kmarshal';
 import { buildVatController } from '../../src/index.js';
-import { kunser } from '../../src/lib/kmarshal.js';
 
 // Dynamic vats are created without metering by default
 
diff --git a/packages/SwingSet/test/run-policy/test-run-policy.js b/packages/SwingSet/test/run-policy/test-run-policy.js
index 2a7838ae4324..a76d17785b29 100644
--- a/packages/SwingSet/test/run-policy/test-run-policy.js
+++ b/packages/SwingSet/test/run-policy/test-run-policy.js
@@ -1,7 +1,8 @@
 // @ts-nocheck
+// eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
+import { kslot, kser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { initializeSwingset, makeSwingsetController } from '../../src/index.js';
 import {
@@ -9,7 +10,6 @@ import {
   computronCounter,
   wallClockWaiter,
 } from '../../src/lib/runPolicies.js';
-import { kslot, kser } from '../../src/lib/kmarshal.js';
 
 async function testCranks(t, mode) {
   /** @type {SwingSetConfig} */
diff --git a/packages/SwingSet/test/test-abandon-export.js b/packages/SwingSet/test/test-abandon-export.js
index df9d76eb771f..55d3762e22e7 100644
--- a/packages/SwingSet/test/test-abandon-export.js
+++ b/packages/SwingSet/test/test-abandon-export.js
@@ -6,7 +6,7 @@ import buildKernel from '../src/kernel/index.js';
 import { initializeKernel } from '../src/controller/initializeKernel.js';
 import { extractMethod } from '../src/lib/kdebug.js';
 import { makeKernelEndowments, buildDispatch } from './util.js';
-import { kser, kunser, kslot } from '../src/lib/kmarshal.js';
+import { kser, kunser, kslot } from '@agoric/kmarshal';
 
 const makeKernel = async () => {
   const endowments = makeKernelEndowments();
diff --git a/packages/SwingSet/test/test-comms.js b/packages/SwingSet/test/test-comms.js
index fc84afcbd17b..2c76f65fb24b 100644
--- a/packages/SwingSet/test/test-comms.js
+++ b/packages/SwingSet/test/test-comms.js
@@ -1,7 +1,8 @@
 // @ts-nocheck
-// eslint-disable-next-line import/order
 import { test } from '../tools/prepare-test-env-ava.js';
 
+// eslint-disable-next-line import/order
+import { kser, kslot } from '@agoric/kmarshal';
 import buildCommsDispatch from '../src/vats/comms/index.js';
 import { flipRemoteSlot } from '../src/vats/comms/parseRemoteSlot.js';
 import { makeState } from '../src/vats/comms/state.js';
@@ -15,7 +16,6 @@ import {
   makeRetireImports,
 } from './util.js';
 import { commsVatDriver } from './commsVatDriver.js';
-import { kser, kslot } from '../src/lib/kmarshal.js';
 
 test('translation', t => {
   const s = makeState(null);
diff --git a/packages/SwingSet/test/test-controller.js b/packages/SwingSet/test/test-controller.js
index 818bbceabbd7..e731182d6fcd 100644
--- a/packages/SwingSet/test/test-controller.js
+++ b/packages/SwingSet/test/test-controller.js
@@ -2,8 +2,8 @@
 // eslint-disable-next-line import/order
 import { test } from '../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import { spawn } from 'child_process';
+import { kser, kunser, kslot } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import {
   buildVatController,
@@ -12,7 +12,6 @@ import {
   makeSwingsetController,
 } from '../src/index.js';
 import { checkKT } from './util.js';
-import { kser, kunser, kslot } from '../src/lib/kmarshal.js';
 
 const emptyVP = kser({});
 
diff --git a/packages/SwingSet/test/test-exomessages.js b/packages/SwingSet/test/test-exomessages.js
index 34474873c8e6..594a63d83057 100644
--- a/packages/SwingSet/test/test-exomessages.js
+++ b/packages/SwingSet/test/test-exomessages.js
@@ -1,7 +1,8 @@
 import { test } from '../tools/prepare-test-env-ava.js';
 
+// eslint-disable-next-line import/order
+import { kunser, kslot, krefOf } from '@agoric/kmarshal';
 import { buildVatController } from '../src/index.js';
-import { kunser, kslot, krefOf } from '../src/lib/kmarshal.js';
 
 async function beginning(t, mode) {
   const config = {
diff --git a/packages/SwingSet/test/test-gc-kernel.js b/packages/SwingSet/test/test-gc-kernel.js
index d841bd85b081..640462f55616 100644
--- a/packages/SwingSet/test/test-gc-kernel.js
+++ b/packages/SwingSet/test/test-gc-kernel.js
@@ -5,8 +5,8 @@ import anylogger from 'anylogger';
 // eslint-disable-next-line import/order
 import { test } from '../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import { assert } from '@agoric/assert';
+import { kser, kunser, kslot } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { waitUntilQuiescent } from '@agoric/internal/src/lib-nodejs/waitUntilQuiescent.js';
 import { parseVatSlot } from '../src/lib/parseVatSlots.js';
@@ -24,7 +24,6 @@ import {
   makeRetireExports,
   makeRetireImports,
 } from './util.js';
-import { kser, kunser, kslot } from '../src/lib/kmarshal.js';
 
 function makeConsole(tag) {
   const log = anylogger(tag);
diff --git a/packages/SwingSet/test/test-kernel.js b/packages/SwingSet/test/test-kernel.js
index 5eb45924d943..81e734fd66e4 100644
--- a/packages/SwingSet/test/test-kernel.js
+++ b/packages/SwingSet/test/test-kernel.js
@@ -2,13 +2,12 @@
 // eslint-disable-next-line import/order
 import { test } from '../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import { Fail } from '@agoric/assert';
+import { kser, kslot } from '@agoric/kmarshal';
 import buildKernel from '../src/kernel/index.js';
 import { initializeKernel } from '../src/controller/initializeKernel.js';
 import { makeVatSlot } from '../src/lib/parseVatSlots.js';
 import { checkKT, extractMessage, makeKernelEndowments } from './util.js';
-import { kser, kslot } from '../src/lib/kmarshal.js';
 
 function oneResolution(promiseID, rejected, data) {
   return [[promiseID, rejected, data]];
diff --git a/packages/SwingSet/test/test-marshal.js b/packages/SwingSet/test/test-marshal.js
index 7655cfe9d882..6e1a8d673cae 100644
--- a/packages/SwingSet/test/test-marshal.js
+++ b/packages/SwingSet/test/test-marshal.js
@@ -4,10 +4,10 @@ import { test } from '../tools/prepare-test-env-ava.js';
 
 import { Far } from '@endo/far';
 import { makePromiseKit } from '@endo/promise-kit';
+import { kser, makeError } from '@agoric/kmarshal';
 import { makeMarshaller } from '@agoric/swingset-liveslots';
 
 import { makeDummyMeterControl } from '../src/kernel/dummyMeterControl.js';
-import { kser, makeError } from '../src/lib/kmarshal.js';
 
 const gcTools = harden({
   WeakRef,
diff --git a/packages/SwingSet/test/test-promises.js b/packages/SwingSet/test/test-promises.js
index f4effda6b08b..6d6a73712e74 100644
--- a/packages/SwingSet/test/test-promises.js
+++ b/packages/SwingSet/test/test-promises.js
@@ -2,12 +2,12 @@
 import { test } from '../tools/prepare-test-env-ava.js';
 
 // eslint-disable-next-line import/order
+import { kser, kslot, kunser } from '@agoric/kmarshal';
 import {
   buildVatController,
   loadBasedir,
   buildKernelBundles,
 } from '../src/index.js';
-import { kser, kslot, kunser } from '../src/lib/kmarshal.js';
 
 const bfile = name => new URL(name, import.meta.url).pathname;
 
diff --git a/packages/SwingSet/test/test-state.js b/packages/SwingSet/test/test-state.js
index 40ea95f0749c..690e0647a8f9 100644
--- a/packages/SwingSet/test/test-state.js
+++ b/packages/SwingSet/test/test-state.js
@@ -2,13 +2,13 @@
 /* eslint-disable no-useless-concat */
 // eslint-disable-next-line import/order
 import { test } from '../tools/prepare-test-env-ava.js';
-// eslint-disable-next-line import/order
+
 import { createHash } from 'crypto';
+import { kser, kslot } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import makeKernelKeeper from '../src/kernel/state/kernelKeeper.js';
 import { makeKernelStats } from '../src/kernel/state/stats.js';
 import { KERNEL_STATS_METRICS } from '../src/kernel/metrics.js';
-import { kser, kslot } from '../src/lib/kmarshal.js';
 import {
   enumeratePrefixedKeys,
   getPrefixedValues,
diff --git a/packages/SwingSet/test/test-vpid-kernel.js b/packages/SwingSet/test/test-vpid-kernel.js
index d34ccb359e79..b8b03997c8b2 100644
--- a/packages/SwingSet/test/test-vpid-kernel.js
+++ b/packages/SwingSet/test/test-vpid-kernel.js
@@ -5,12 +5,12 @@ import { test } from '../tools/prepare-test-env-ava.js';
 
 import anylogger from 'anylogger';
 import { Fail } from '@agoric/assert';
+import { kser, kslot } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { waitUntilQuiescent } from '@agoric/internal/src/lib-nodejs/waitUntilQuiescent.js';
 
 import buildKernel from '../src/kernel/index.js';
 import { initializeKernel } from '../src/controller/initializeKernel.js';
-import { kser, kslot } from '../src/lib/kmarshal.js';
 
 import { buildDispatch } from './util.js';
 
diff --git a/packages/SwingSet/test/test-xsnap-errors.js b/packages/SwingSet/test/test-xsnap-errors.js
index 8b41b23dad15..4eb6e3f404b9 100644
--- a/packages/SwingSet/test/test-xsnap-errors.js
+++ b/packages/SwingSet/test/test-xsnap-errors.js
@@ -6,6 +6,7 @@ import { spawn } from 'child_process';
 import fs from 'fs';
 import { tmpName } from 'tmp';
 import bundleSource from '@endo/bundle-source';
+import { kser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 
 import { makeXsSubprocessFactory } from '../src/kernel/vat-loader/manager-subprocess-xsnap.js';
@@ -14,7 +15,6 @@ import {
   makeXsnapBundleData,
 } from '../src/controller/bundle-handler.js';
 import { makeStartXSnap } from '../src/controller/startXSnap.js';
-import { kser } from '../src/lib/kmarshal.js';
 
 test('child termination distinguished from meter exhaustion', async t => {
   /** @type { ReturnType<typeof spawn> } */
diff --git a/packages/SwingSet/test/timer/test-timer.js b/packages/SwingSet/test/timer/test-timer.js
index 49f3c2936388..2df4742240a4 100644
--- a/packages/SwingSet/test/timer/test-timer.js
+++ b/packages/SwingSet/test/timer/test-timer.js
@@ -1,11 +1,10 @@
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
+import { kunser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { initializeSwingset, makeSwingsetController } from '../../src/index.js';
 import { buildTimer } from '../../src/devices/timer/timer.js';
-import { kunser } from '../../src/lib/kmarshal.js';
 
 const bfile = name => new URL(name, import.meta.url).pathname;
 
diff --git a/packages/SwingSet/test/transcript/test-state-sync-reload.js b/packages/SwingSet/test/transcript/test-state-sync-reload.js
index 83e9b983e52e..ec6af96d47c3 100644
--- a/packages/SwingSet/test/transcript/test-state-sync-reload.js
+++ b/packages/SwingSet/test/transcript/test-state-sync-reload.js
@@ -1,7 +1,9 @@
 // @ts-nocheck
 /* eslint @typescript-eslint/no-floating-promises: "warn" */
 import test from 'ava';
+
 import tmp from 'tmp';
+import { kunser } from '@agoric/kmarshal';
 import {
   initSwingStore,
   makeSwingStoreExporter,
@@ -9,7 +11,6 @@ import {
 } from '@agoric/swing-store';
 import { initializeSwingset, makeSwingsetController } from '../../src/index.js';
 import { buildKernelBundle } from '../../src/controller/initializeSwingset.js';
-import { kunser } from '../../src/lib/kmarshal.js';
 
 /**
  * @param {string} [prefix]
diff --git a/packages/SwingSet/test/transcript/test-transcript-entries.js b/packages/SwingSet/test/transcript/test-transcript-entries.js
index aad87dedb7e4..36b7cded0e27 100644
--- a/packages/SwingSet/test/transcript/test-transcript-entries.js
+++ b/packages/SwingSet/test/transcript/test-transcript-entries.js
@@ -1,10 +1,11 @@
 // @ts-nocheck
 /* eslint @typescript-eslint/no-floating-promises: "warn" */
 import test from 'ava';
+
+import { kunser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { initializeSwingset, makeSwingsetController } from '../../src/index.js';
 import { buildKernelBundle } from '../../src/controller/initializeSwingset.js';
-import { kunser } from '../../src/lib/kmarshal.js';
 
 const bfile = name => new URL(name, import.meta.url).pathname;
 
diff --git a/packages/SwingSet/test/upgrade/test-upgrade-replay.js b/packages/SwingSet/test/upgrade/test-upgrade-replay.js
index b8ec534896cc..6c02487e8336 100644
--- a/packages/SwingSet/test/upgrade/test-upgrade-replay.js
+++ b/packages/SwingSet/test/upgrade/test-upgrade-replay.js
@@ -3,6 +3,7 @@
 import { test } from '../../tools/prepare-test-env-ava.js';
 
 import { assert } from '@agoric/assert';
+import { kser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import {
   buildKernelBundles,
@@ -10,7 +11,6 @@ import {
   makeSwingsetController,
 } from '../../src/index.js';
 import { bundleOpts } from '../util.js';
-import { kser } from '../../src/lib/kmarshal.js';
 
 function bfile(name) {
   return new URL(name, import.meta.url).pathname;
diff --git a/packages/SwingSet/test/upgrade/test-upgrade.js b/packages/SwingSet/test/upgrade/test-upgrade.js
index f5641617e600..d30fc45e6761 100644
--- a/packages/SwingSet/test/upgrade/test-upgrade.js
+++ b/packages/SwingSet/test/upgrade/test-upgrade.js
@@ -2,14 +2,13 @@
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import { assert } from '@agoric/assert';
 import bundleSource from '@endo/bundle-source';
 import { objectMap } from '@agoric/internal';
+import { kser, kunser, krefOf } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { parseReachableAndVatSlot } from '../../src/kernel/state/reachable.js';
 import { parseVatSlot } from '../../src/lib/parseVatSlots.js';
-import { kser, kunser, krefOf } from '../../src/lib/kmarshal.js';
 import {
   buildKernelBundles,
   initializeSwingset,
diff --git a/packages/SwingSet/test/util.js b/packages/SwingSet/test/util.js
index 669ce24252c2..aedaab707b80 100644
--- a/packages/SwingSet/test/util.js
+++ b/packages/SwingSet/test/util.js
@@ -3,10 +3,10 @@ import anylogger from 'anylogger';
 
 import bundleSource from '@endo/bundle-source';
 
+import { kser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { waitUntilQuiescent } from '@agoric/internal/src/lib-nodejs/waitUntilQuiescent.js';
 import { extractMessage, ignore, vstr } from './vat-util.js';
-import { kser } from '../src/lib/kmarshal.js';
 
 export { extractMessage, ignore, vstr };
 
diff --git a/packages/SwingSet/test/vat-admin/terminate/test-terminate-replay.js b/packages/SwingSet/test/vat-admin/terminate/test-terminate-replay.js
index 45e4c17c3743..aaa555ed2d5b 100644
--- a/packages/SwingSet/test/vat-admin/terminate/test-terminate-replay.js
+++ b/packages/SwingSet/test/vat-admin/terminate/test-terminate-replay.js
@@ -1,7 +1,8 @@
 // @ts-nocheck
 // eslint-disable-next-line import/order
 import { test } from '../../../tools/prepare-test-env-ava.js';
-// eslint-disable-next-line import/order
+
+import { kser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 
 import {
@@ -9,7 +10,6 @@ import {
   loadSwingsetConfigFile,
   buildKernelBundles,
 } from '../../../src/index.js';
-import { kser } from '../../../src/lib/kmarshal.js';
 
 test.before(async t => {
   const kernelBundles = await buildKernelBundles();
diff --git a/packages/SwingSet/test/vat-admin/terminate/test-terminate.js b/packages/SwingSet/test/vat-admin/terminate/test-terminate.js
index c4e194a0c970..750862e084b5 100644
--- a/packages/SwingSet/test/vat-admin/terminate/test-terminate.js
+++ b/packages/SwingSet/test/vat-admin/terminate/test-terminate.js
@@ -1,7 +1,8 @@
 // @ts-nocheck
 // eslint-disable-next-line import/order
 import { test } from '../../../tools/prepare-test-env-ava.js';
-// eslint-disable-next-line import/order
+
+import { kser, kunser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 
 import {
@@ -9,7 +10,6 @@ import {
   loadSwingsetConfigFile,
   buildKernelBundles,
 } from '../../../src/index.js';
-import { kser, kunser } from '../../../src/lib/kmarshal.js';
 import { enumeratePrefixedKeys } from '../../../src/kernel/state/storageHelper.js';
 import { restartVatAdminVat } from '../../util.js';
 
diff --git a/packages/SwingSet/test/vat-admin/test-create-vat.js b/packages/SwingSet/test/vat-admin/test-create-vat.js
index c853bd85c92e..a23a686752ed 100644
--- a/packages/SwingSet/test/vat-admin/test-create-vat.js
+++ b/packages/SwingSet/test/vat-admin/test-create-vat.js
@@ -1,8 +1,9 @@
 // @ts-nocheck
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
-// eslint-disable-next-line import/order
+
 import bundleSource from '@endo/bundle-source';
+import { kunser, krefOf } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import {
   buildKernelBundles,
@@ -11,7 +12,6 @@ import {
   loadBasedir,
 } from '../../src/index.js';
 import { bundleOpts, restartVatAdminVat } from '../util.js';
-import { kunser, krefOf } from '../../src/lib/kmarshal.js';
 import { extractMethod } from '../../src/lib/kdebug.js';
 
 function nonBundleFunction(_E) {
diff --git a/packages/SwingSet/test/vat-admin/test-replay.js b/packages/SwingSet/test/vat-admin/test-replay.js
index 6011f7a93632..24cb2dfd24f2 100644
--- a/packages/SwingSet/test/vat-admin/test-replay.js
+++ b/packages/SwingSet/test/vat-admin/test-replay.js
@@ -1,10 +1,10 @@
 // @ts-nocheck
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
-// eslint-disable-next-line import/order
+
+import { kser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { buildKernelBundles, buildVatController } from '../../src/index.js';
-import { kser } from '../../src/lib/kmarshal.js';
 
 function copy(data) {
   return JSON.parse(JSON.stringify(data));
diff --git a/packages/SwingSet/test/vat-direct.js b/packages/SwingSet/test/vat-direct.js
index 52bfd3c2d4a8..a9121801b92c 100644
--- a/packages/SwingSet/test/vat-direct.js
+++ b/packages/SwingSet/test/vat-direct.js
@@ -1,6 +1,6 @@
 // @ts-nocheck
+import { krefOf, kser, kslot, kunser } from '@agoric/kmarshal';
 import { extractMessage } from './vat-util.js';
-import { krefOf, kser, kslot, kunser } from '../src/lib/kmarshal.js';
 
 /**
  * A testing vat that generically exposes kernel interactions
diff --git a/packages/SwingSet/test/vat-syscall-failure.js b/packages/SwingSet/test/vat-syscall-failure.js
index 861c73e399e1..4c1af219fda0 100644
--- a/packages/SwingSet/test/vat-syscall-failure.js
+++ b/packages/SwingSet/test/vat-syscall-failure.js
@@ -1,5 +1,5 @@
+import { kser } from '@agoric/kmarshal';
 import { extractMessage } from './vat-util.js';
-import { kser } from '../src/lib/kmarshal.js';
 
 export default function setup(syscall, _state, _helpers, vatPowers) {
   function dispatch(vatDeliverObject) {
diff --git a/packages/SwingSet/test/vat-timer-upgrade/test-vat-timer-upgrade.js b/packages/SwingSet/test/vat-timer-upgrade/test-vat-timer-upgrade.js
index 60613c555f26..138a203c1615 100644
--- a/packages/SwingSet/test/vat-timer-upgrade/test-vat-timer-upgrade.js
+++ b/packages/SwingSet/test/vat-timer-upgrade/test-vat-timer-upgrade.js
@@ -1,12 +1,11 @@
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import bundleSource from '@endo/bundle-source';
+import { kunser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { initializeSwingset, makeSwingsetController } from '../../src/index.js';
 import { buildTimer } from '../../src/devices/timer/timer.js';
-import { kunser } from '../../src/lib/kmarshal.js';
 
 const bfile = name => new URL(name, import.meta.url).pathname;
 
diff --git a/packages/SwingSet/test/vat-util.js b/packages/SwingSet/test/vat-util.js
index ee55521b73f2..e03fdcf3c971 100644
--- a/packages/SwingSet/test/vat-util.js
+++ b/packages/SwingSet/test/vat-util.js
@@ -2,7 +2,7 @@
 // modules
 
 import { assert } from '@agoric/assert';
-import { kser, kunser } from '../src/lib/kmarshal.js';
+import { kser, kunser } from '@agoric/kmarshal';
 
 export function extractMessage(vatDeliverObject) {
   const [type, ...vdoargs] = vatDeliverObject;
diff --git a/packages/SwingSet/test/virtualObjects/collection-slots/test-collection-slots.js b/packages/SwingSet/test/virtualObjects/collection-slots/test-collection-slots.js
index d69a960a0793..f0d629a86e7a 100644
--- a/packages/SwingSet/test/virtualObjects/collection-slots/test-collection-slots.js
+++ b/packages/SwingSet/test/virtualObjects/collection-slots/test-collection-slots.js
@@ -2,8 +2,8 @@
 // eslint-disable-next-line import/order
 import { test } from '../../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import { assert } from '@agoric/assert';
+import { kunser, krefOf } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { parseReachableAndVatSlot } from '../../../src/kernel/state/reachable.js';
 import {
@@ -11,8 +11,6 @@ import {
   makeSwingsetController,
 } from '../../../src/index.js';
 
-import { kunser, krefOf } from '../../../src/lib/kmarshal.js';
-
 function bfile(name) {
   return new URL(name, import.meta.url).pathname;
 }
diff --git a/packages/SwingSet/test/virtualObjects/delete-stored-vo/test-delete-stored-vo.js b/packages/SwingSet/test/virtualObjects/delete-stored-vo/test-delete-stored-vo.js
index 12025568f134..291c664f51bd 100644
--- a/packages/SwingSet/test/virtualObjects/delete-stored-vo/test-delete-stored-vo.js
+++ b/packages/SwingSet/test/virtualObjects/delete-stored-vo/test-delete-stored-vo.js
@@ -2,15 +2,14 @@
 // eslint-disable-next-line import/order
 import { test } from '../../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
 import { assert } from '@agoric/assert';
+import { kunser, krefOf } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { parseReachableAndVatSlot } from '../../../src/kernel/state/reachable.js';
 import {
   initializeSwingset,
   makeSwingsetController,
 } from '../../../src/index.js';
-import { kunser, krefOf } from '../../../src/lib/kmarshal.js';
 
 function bfile(name) {
   return new URL(name, import.meta.url).pathname;
diff --git a/packages/SwingSet/test/virtualObjects/test-facet-retention.js b/packages/SwingSet/test/virtualObjects/test-facet-retention.js
index 05d1cc03b4d5..389fb6f12bd3 100644
--- a/packages/SwingSet/test/virtualObjects/test-facet-retention.js
+++ b/packages/SwingSet/test/virtualObjects/test-facet-retention.js
@@ -1,10 +1,10 @@
 // @ts-nocheck
 import test from 'ava';
+
+import { kunser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { buildVatController } from '../../src/index.js';
 
-import { kunser } from '../../src/lib/kmarshal.js';
-
 // Check that facets which don't reference their state still keep their cohort alive
 
 // Test what happens when userspace builds recognizers for various VO
diff --git a/packages/SwingSet/test/virtualObjects/test-representatives.js b/packages/SwingSet/test/virtualObjects/test-representatives.js
index 12e2395fdd30..0a9a8b812c94 100644
--- a/packages/SwingSet/test/virtualObjects/test-representatives.js
+++ b/packages/SwingSet/test/virtualObjects/test-representatives.js
@@ -2,6 +2,7 @@
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
+import { kser, kslot } from '@agoric/kmarshal';
 import { M } from '@agoric/store';
 import { initSwingStore } from '@agoric/swing-store';
 import {
@@ -11,7 +12,6 @@ import {
 } from '../../src/index.js';
 import makeNextLog from '../make-nextlog.js';
 
-import { kser, kslot } from '../../src/lib/kmarshal.js';
 import { enumeratePrefixedKeys } from '../../src/kernel/state/storageHelper.js';
 import { vstr } from '../util.js';
 
diff --git a/packages/SwingSet/test/virtualObjects/test-weakcollections.js b/packages/SwingSet/test/virtualObjects/test-weakcollections.js
index 88dcb8a3a61b..d6a401ff9273 100644
--- a/packages/SwingSet/test/virtualObjects/test-weakcollections.js
+++ b/packages/SwingSet/test/virtualObjects/test-weakcollections.js
@@ -1,11 +1,11 @@
 // eslint-disable-next-line import/order
 import { test } from '../../tools/prepare-test-env-ava.js';
 
+import { kser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import engineGC from '@agoric/internal/src/lib-nodejs/engine-gc.js';
 import { initializeSwingset, makeSwingsetController } from '../../src/index.js';
 import makeNextLog from '../make-nextlog.js';
-import { kser } from '../../src/lib/kmarshal.js';
 
 test('weakMap in vat', async t => {
   const config = {
diff --git a/packages/SwingSet/test/virtualObjects/vdata-promises/test-vdata-promises.js b/packages/SwingSet/test/virtualObjects/vdata-promises/test-vdata-promises.js
index 6c8676586d52..6d7bf9aa666f 100644
--- a/packages/SwingSet/test/virtualObjects/vdata-promises/test-vdata-promises.js
+++ b/packages/SwingSet/test/virtualObjects/vdata-promises/test-vdata-promises.js
@@ -1,14 +1,13 @@
 // eslint-disable-next-line import/order
 import { test } from '../../../tools/prepare-test-env-ava.js';
 
-// eslint-disable-next-line import/order
+import { kunser } from '@agoric/kmarshal';
 import { initSwingStore } from '@agoric/swing-store';
 import { parseReachableAndVatSlot } from '../../../src/kernel/state/reachable.js';
 import {
   initializeSwingset,
   makeSwingsetController,
 } from '../../../src/index.js';
-import { kunser } from '../../../src/lib/kmarshal.js';
 
 function bfile(name) {
   return new URL(name, import.meta.url).pathname;
diff --git a/packages/SwingSet/test/workers/test-worker.js b/packages/SwingSet/test/workers/test-worker.js
index c1750779b127..ec49a67e0ffc 100644
--- a/packages/SwingSet/test/workers/test-worker.js
+++ b/packages/SwingSet/test/workers/test-worker.js
@@ -1,7 +1,8 @@
 import { test } from '../../tools/prepare-test-env-ava.js';
 
+// eslint-disable-next-line import/order
+import { kunser } from '@agoric/kmarshal';
 import { loadBasedir, buildVatController } from '../../src/index.js';
-import { kunser } from '../../src/lib/kmarshal.js';
 
 const expected = [
   ['B good', 'C good', 'F good', 'three good', 'exit good', 'exitWF good'],
diff --git a/packages/agoric-cli/src/sdk-package-names.js b/packages/agoric-cli/src/sdk-package-names.js
index a4371b52d2d2..2db4676d928c 100644
--- a/packages/agoric-cli/src/sdk-package-names.js
+++ b/packages/agoric-cli/src/sdk-package-names.js
@@ -20,6 +20,7 @@ export default [
   "@agoric/import-manager",
   "@agoric/inter-protocol",
   "@agoric/internal",
+  "@agoric/kmarshal",
   "@agoric/network",
   "@agoric/notifier",
   "@agoric/pegasus",
diff --git a/packages/boot/package.json b/packages/boot/package.json
index db0c04e4b794..9dde12c8c9c1 100644
--- a/packages/boot/package.json
+++ b/packages/boot/package.json
@@ -42,6 +42,7 @@
     "@agoric/deploy-script-support": "^0.10.3",
     "@agoric/governance": "^0.10.3",
     "@agoric/inter-protocol": "^0.16.1",
+    "@agoric/kmarshal": "^0.1.0",
     "@agoric/store": "^0.9.2",
     "@agoric/swing-store": "^0.9.1",
     "@agoric/swingset-liveslots": "^0.10.2",
diff --git a/packages/boot/test/bootstrapTests/supports.ts b/packages/boot/test/bootstrapTests/supports.ts
index 9d0e0908ae58..fd245138e762 100644
--- a/packages/boot/test/bootstrapTests/supports.ts
+++ b/packages/boot/test/bootstrapTests/supports.ts
@@ -14,7 +14,7 @@ import { unmarshalFromVstorage } from '@agoric/internal/src/marshal.js';
 import { makeFakeStorageKit } from '@agoric/internal/src/storage-test-utils.js';
 import { initSwingStore } from '@agoric/swing-store';
 import { loadSwingsetConfigFile } from '@agoric/swingset-vat';
-import { krefOf, kunser } from '@agoric/swingset-vat/src/lib/kmarshal.js';
+import { krefOf, kunser } from '@agoric/kmarshal';
 import { TimeMath, Timestamp } from '@agoric/time';
 import {
   boardSlottingMarshaller,
diff --git a/packages/kmarshal/package.json b/packages/kmarshal/package.json
new file mode 100644
index 000000000000..493c73f74432
--- /dev/null
+++ b/packages/kmarshal/package.json
@@ -0,0 +1,43 @@
+{
+  "name": "@agoric/kmarshal",
+  "version": "0.1.0",
+  "description": "Token-only marshaller for kernel and tests",
+  "type": "module",
+  "main": "./src/kmarshal.js",
+  "exports": {
+    ".": "./src/kmarshal.js"
+  },
+  "repository": "https://github.com/Agoric/agoric-sdk",
+  "author": "Agoric",
+  "license": "Apache-2.0",
+  "scripts": {
+    "build": "exit 0",
+    "test": "ava",
+    "test:c8": "c8 $C8_OPTIONS ava --config=ava-nesm.config.js",
+    "test:xs": "exit 0",
+    "lint-fix": "yarn lint:eslint --fix",
+    "lint": "run-s --continue-on-error lint:*",
+    "lint:types": "tsc",
+    "lint:eslint": "eslint ."
+  },
+  "dependencies": {
+    "@endo/far": "^0.2.21",
+    "@endo/marshal": "^0.8.8",
+    "@agoric/assert": "^0.6.0"
+  },
+  "devDependencies": {
+    "ava": "^5.3.0"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "ava": {
+    "files": [
+      "test/**/test-*.js"
+    ],
+    "require": [
+      "@endo/init/debug.js"
+    ],
+    "timeout": "2m"
+  }
+}
diff --git a/packages/SwingSet/src/lib/kmarshal.js b/packages/kmarshal/src/kmarshal.js
similarity index 100%
rename from packages/SwingSet/src/lib/kmarshal.js
rename to packages/kmarshal/src/kmarshal.js
diff --git a/packages/kmarshal/test/test-basic.js b/packages/kmarshal/test/test-basic.js
new file mode 100644
index 000000000000..60ad70c3c8f4
--- /dev/null
+++ b/packages/kmarshal/test/test-basic.js
@@ -0,0 +1,29 @@
+import test from 'ava';
+
+import { kser, kunser, krefOf } from '../src/kmarshal.js';
+
+test('sanity check', t => {
+  const serUndefined = kser(undefined);
+  t.deepEqual(serUndefined, {
+    body: '#"#undefined"',
+    slots: [],
+  });
+  t.is(kunser(serUndefined), undefined);
+
+  const serNumber = kser(47);
+  t.deepEqual(serNumber, {
+    body: '#47',
+    slots: [],
+  });
+  t.is(kunser(serNumber), 47);
+
+  const serString = kser('foo');
+  t.deepEqual(serString, {
+    body: '#"foo"',
+    slots: [],
+  });
+  t.is(kunser(serString), 'foo');
+
+  const remotable = kunser({ body: '#"$0"', slots: ['ko47'] });
+  t.is(krefOf(remotable), 'ko47');
+});
diff --git a/packages/kmarshal/tsconfig.json b/packages/kmarshal/tsconfig.json
new file mode 100644
index 000000000000..282b3f23e362
--- /dev/null
+++ b/packages/kmarshal/tsconfig.json
@@ -0,0 +1,12 @@
+// This file can contain .js-specific Typescript compiler config.
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "allowSyntheticDefaultImports": true,
+    "maxNodeModuleJsDepth": 2,
+  },
+  "include": [
+    "src/**/*.js",
+    "test/**/*.js"
+  ]
+}
diff --git a/packages/notifier/package.json b/packages/notifier/package.json
index 18f917a0a07a..ac9e39936c8c 100644
--- a/packages/notifier/package.json
+++ b/packages/notifier/package.json
@@ -42,6 +42,7 @@
     "@endo/promise-kit": "^0.2.59"
   },
   "devDependencies": {
+    "@agoric/kmarshal": "^0.1.0",
     "@agoric/swingset-liveslots": "^0.10.2",
     "@agoric/swing-store": "^0.9.1",
     "@agoric/swingset-vat": "^0.32.2",
diff --git a/packages/notifier/test/test-publish-kit.js b/packages/notifier/test/test-publish-kit.js
index 15eb84a8a9c1..2a7216bedce8 100644
--- a/packages/notifier/test/test-publish-kit.js
+++ b/packages/notifier/test/test-publish-kit.js
@@ -10,7 +10,7 @@ import {
   makeSwingsetController,
 } from '@agoric/swingset-vat';
 import { initSwingStore } from '@agoric/swing-store';
-import { kunser } from '@agoric/swingset-vat/src/lib/kmarshal.js';
+import { kunser } from '@agoric/kmarshal';
 import { makeScalarBigMapStore } from '@agoric/vat-data/src/vat-data-bindings.js';
 import {
   makePublishKit,
diff --git a/packages/swingset-liveslots/package.json b/packages/swingset-liveslots/package.json
index 59fddfc92b17..f387571a2128 100644
--- a/packages/swingset-liveslots/package.json
+++ b/packages/swingset-liveslots/package.json
@@ -31,7 +31,8 @@
     "@endo/promise-kit": "^0.2.59"
   },
   "devDependencies": {
-    "ava": "^5.3.0"
+    "ava": "^5.3.0",
+    "@agoric/kmarshal": "^0.1.0"
   },
   "files": [
     "src/**/*.js",
diff --git a/packages/swingset-liveslots/test/gc-helpers.js b/packages/swingset-liveslots/test/gc-helpers.js
index 8736a587895c..376ac94365b6 100644
--- a/packages/swingset-liveslots/test/gc-helpers.js
+++ b/packages/swingset-liveslots/test/gc-helpers.js
@@ -2,7 +2,7 @@
 
 import { Far } from '@endo/marshal';
 import { M } from '@agoric/store';
-import { kslot, kser } from './kmarshal.js';
+import { kslot, kser } from '@agoric/kmarshal';
 import { parseVatSlot } from '../src/parseVatSlots.js';
 
 // These tests follow the model described in
diff --git a/packages/swingset-liveslots/test/kmarshal.js b/packages/swingset-liveslots/test/kmarshal.js
deleted file mode 100644
index e623b4101609..000000000000
--- a/packages/swingset-liveslots/test/kmarshal.js
+++ /dev/null
@@ -1,79 +0,0 @@
-import { Far, makeMarshal, passStyleOf } from '@endo/marshal';
-import { assert } from '@agoric/assert';
-
-// Simple wrapper for serializing and unserializing marshalled values inside the
-// kernel, where we don't actually want to use clists nor actually allocate real
-// objects, but instead to stay entirely within the domain of krefs.  This is
-// used to enable syntactic manipulation of serialized values while remaining
-// agnostic about the internal details of the serialization encoding.
-
-const refMap = new WeakMap();
-
-export const kslot = (kref, iface) => {
-  assert.typeof(kref, 'string');
-  if (iface && iface.startsWith('Alleged: ')) {
-    // Encoder prepends "Alleged: " to iface string, but the decoder doesn't strip it
-    // Unclear whether it's the decoder or me who is wrong
-    iface = iface.slice(9);
-  }
-  if (
-    kref.startsWith('p') ||
-    kref.startsWith('kp') ||
-    kref.startsWith('lp') ||
-    kref.startsWith('rp')
-  ) {
-    // TODO: temporary hack because smallcaps encodes promise references
-    // differently from remotable object references, and the current version of
-    // the smallcaps decoder annoyingly insists that if the encoded body string
-    // says a slot is a promise, then convertSlotToVal had better by damn return
-    // an actual Promise, even if, as in the intended use case here, we neither
-    // want nor need a promise, nor the overhead of a map to keep track of it
-    // with.  This behavior is in service of defense against a hypothesized
-    // security issue whose exact nature has largely been forgotton in the
-    // months since it was first encountered.  MarkM is currently researching
-    // what the problem was thought to have been, to see if it is real and to
-    // understand it if so.  This will eventually result in either changes to
-    // the smallcaps encoding or to the marshal setup API to support the purely
-    // manipulative use case.  In the meantime, this ugliness...
-    const p = new Promise(() => undefined);
-    refMap.set(p, kref);
-    return harden(p);
-  } else {
-    const o = Far(iface, {
-      iface: () => iface,
-      getKref: () => `${kref}`,
-    });
-    return o;
-  }
-};
-
-export const krefOf = obj => {
-  const fromMap = refMap.get(obj);
-  if (fromMap) {
-    return fromMap;
-  }
-  // When krefOf() is called as part of kmarshal.serialize, marshal
-  // will only give it things that are 'remotable' (Promises and the
-  // Far objects created by kslot()).  When krefOf() is called by
-  // kernel code (as part of extractSingleSlot() or the vat-comms
-  // equivalent), it ought to throw if 'obj' is not one of the Far
-  // objects created by our kslot().
-  assert.equal(passStyleOf(obj), 'remotable', obj);
-  const getKref = obj.getKref;
-  assert.typeof(getKref, 'function');
-  return getKref();
-};
-
-const kmarshal = makeMarshal(krefOf, kslot, {
-  serializeBodyFormat: 'smallcaps',
-  errorTagging: 'off',
-});
-
-export const kser = value => kmarshal.serialize(harden(value));
-
-export const kunser = serializedValue => kmarshal.unserialize(serializedValue);
-
-export function makeError(message) {
-  assert.typeof(message, 'string');
-  return kser(Error(message));
-}
diff --git a/packages/swingset-liveslots/test/liveslots-helpers.js b/packages/swingset-liveslots/test/liveslots-helpers.js
index 1f101af07e64..8926bf72d160 100644
--- a/packages/swingset-liveslots/test/liveslots-helpers.js
+++ b/packages/swingset-liveslots/test/liveslots-helpers.js
@@ -1,6 +1,7 @@
 /* global WeakRef, FinalizationRegistry */
-import engineGC from './engine-gc.js';
+import { kser } from '@agoric/kmarshal';
 
+import engineGC from './engine-gc.js';
 import { waitUntilQuiescent } from './waitUntilQuiescent.js';
 import { makeGcAndFinalize } from './gc-and-finalize.js';
 import { makeDummyMeterControl } from './dummyMeterControl.js';
@@ -12,7 +13,6 @@ import {
   makeRetireExports,
   makeBringOutYourDead,
 } from './util.js';
-import { kser } from './kmarshal.js';
 
 /**
  * @param {object} [options]
diff --git a/packages/swingset-liveslots/test/storeGC/test-lifecycle.js b/packages/swingset-liveslots/test/storeGC/test-lifecycle.js
index 62bee16ccdb7..2f998917b04e 100644
--- a/packages/swingset-liveslots/test/storeGC/test-lifecycle.js
+++ b/packages/swingset-liveslots/test/storeGC/test-lifecycle.js
@@ -1,12 +1,12 @@
 // @ts-nocheck
 import test from 'ava';
 
+import { kslot, kunser } from '@agoric/kmarshal';
 import {
   setupTestLiveslots,
   findSyscallsByType,
 } from '../liveslots-helpers.js';
 import { buildRootObject, mainHeldIdx, mapRef } from '../gc-helpers.js';
-import { kslot, kunser } from '../kmarshal.js';
 import { parseVatSlot } from '../../src/parseVatSlots.js';
 
 // These tests follow the model described in
diff --git a/packages/swingset-liveslots/test/storeGC/test-refcount-management.js b/packages/swingset-liveslots/test/storeGC/test-refcount-management.js
index c5f88d56d61a..65fd4aaa4263 100644
--- a/packages/swingset-liveslots/test/storeGC/test-refcount-management.js
+++ b/packages/swingset-liveslots/test/storeGC/test-refcount-management.js
@@ -1,5 +1,6 @@
 import test from 'ava';
 
+import { kslot } from '@agoric/kmarshal';
 import {
   findSyscallsByType,
   setupTestLiveslots,
@@ -11,7 +12,6 @@ import {
   refValString,
   assertCollectionDeleted,
 } from '../gc-helpers.js';
-import { kslot } from '../kmarshal.js';
 import { vstr } from '../util.js';
 
 // These tests follow the model described in
diff --git a/packages/swingset-liveslots/test/storeGC/test-weak-key.js b/packages/swingset-liveslots/test/storeGC/test-weak-key.js
index d5001aa50571..a074705240bf 100644
--- a/packages/swingset-liveslots/test/storeGC/test-weak-key.js
+++ b/packages/swingset-liveslots/test/storeGC/test-weak-key.js
@@ -1,5 +1,6 @@
 import test from 'ava';
 
+import { kslot } from '@agoric/kmarshal';
 import { setupTestLiveslots } from '../liveslots-helpers.js';
 import {
   buildRootObject,
@@ -7,7 +8,6 @@ import {
   assertCollectionDeleted,
   deduceCollectionID,
 } from '../gc-helpers.js';
-import { kslot } from '../kmarshal.js';
 import { vstr } from '../util.js';
 
 // These tests follow the model described in test-virtualObjectGC.js
diff --git a/packages/swingset-liveslots/test/test-baggage.js b/packages/swingset-liveslots/test/test-baggage.js
index be4b2013514b..a1523b647a41 100644
--- a/packages/swingset-liveslots/test/test-baggage.js
+++ b/packages/swingset-liveslots/test/test-baggage.js
@@ -1,9 +1,9 @@
 import test from 'ava';
 
 import { Far } from '@endo/marshal';
+import { kunser } from '@agoric/kmarshal';
 import { setupTestLiveslots } from './liveslots-helpers.js';
 import { vstr } from './util.js';
-import { kunser } from './kmarshal.js';
 import { parseVatSlot } from '../src/parseVatSlots.js';
 
 function buildRootObject(vatPowers, vatParameters, baggage) {
diff --git a/packages/swingset-liveslots/test/test-collection-schema-refcount.js b/packages/swingset-liveslots/test/test-collection-schema-refcount.js
index 7754e119ab94..e563ecf52273 100644
--- a/packages/swingset-liveslots/test/test-collection-schema-refcount.js
+++ b/packages/swingset-liveslots/test/test-collection-schema-refcount.js
@@ -1,9 +1,9 @@
 import test from 'ava';
 
 import { Far } from '@endo/marshal';
+import { kser } from '@agoric/kmarshal';
 import { makeLiveSlots } from '../src/liveslots.js';
 import { parseVatSlot } from '../src/parseVatSlots.js';
-import { kser } from './kmarshal.js';
 import { buildSyscall } from './liveslots-helpers.js';
 import { makeStartVat, makeBringOutYourDead } from './util.js';
 import { makeMockGC } from './mock-gc.js';
diff --git a/packages/swingset-liveslots/test/test-collection-upgrade.js b/packages/swingset-liveslots/test/test-collection-upgrade.js
index e8f1719c7c43..ca3292096595 100644
--- a/packages/swingset-liveslots/test/test-collection-upgrade.js
+++ b/packages/swingset-liveslots/test/test-collection-upgrade.js
@@ -1,10 +1,10 @@
 import test from 'ava';
 
 import { Far } from '@endo/marshal';
+import { kser } from '@agoric/kmarshal';
 import { M } from '@agoric/store';
 import { makeLiveSlots } from '../src/liveslots.js';
 import { parseVatSlot } from '../src/parseVatSlots.js';
-import { kser } from './kmarshal.js';
 import { buildSyscall } from './liveslots-helpers.js';
 import { makeStartVat } from './util.js';
 import { makeMockGC } from './mock-gc.js';
diff --git a/packages/swingset-liveslots/test/test-dropped-collection-weakrefs.js b/packages/swingset-liveslots/test/test-dropped-collection-weakrefs.js
index 466f5476399c..8c197fc79ea3 100644
--- a/packages/swingset-liveslots/test/test-dropped-collection-weakrefs.js
+++ b/packages/swingset-liveslots/test/test-dropped-collection-weakrefs.js
@@ -1,7 +1,7 @@
 import test from 'ava';
 import { Far } from '@endo/marshal';
+import { kser } from '@agoric/kmarshal';
 import { makeLiveSlots } from '../src/liveslots.js';
-import { kser } from './kmarshal.js';
 import { buildSyscall } from './liveslots-helpers.js';
 import { makeStartVat } from './util.js';
 import { makeMockGC } from './mock-gc.js';
diff --git a/packages/swingset-liveslots/test/test-gc-sensitivity.js b/packages/swingset-liveslots/test/test-gc-sensitivity.js
index 86215af4d2e2..4952446c9115 100644
--- a/packages/swingset-liveslots/test/test-gc-sensitivity.js
+++ b/packages/swingset-liveslots/test/test-gc-sensitivity.js
@@ -1,9 +1,9 @@
 // @ts-nocheck
 import test from 'ava';
 import { Far } from '@endo/marshal';
+import { kser } from '@agoric/kmarshal';
 import { buildSyscall } from './liveslots-helpers.js';
 import { makeLiveSlots } from '../src/liveslots.js';
-import { kser } from './kmarshal.js';
 import { makeMockGC } from './mock-gc.js';
 import { makeMessage, makeStartVat } from './util.js';
 
diff --git a/packages/swingset-liveslots/test/test-handled-promises.js b/packages/swingset-liveslots/test/test-handled-promises.js
index fc14cfae6341..e13c0055cae5 100644
--- a/packages/swingset-liveslots/test/test-handled-promises.js
+++ b/packages/swingset-liveslots/test/test-handled-promises.js
@@ -7,7 +7,7 @@ import { makePromiseKit } from '@endo/promise-kit';
 // Disabled to avoid circular dependencies.
 // import { makeStoreUtils } from '@agoric/vat-data/src/vat-data-bindings.js';
 // import { makeExoUtils } from '@agoric/vat-data/src/exo-utils.js';
-import { kslot, kser } from './kmarshal.js';
+import { kslot, kser } from '@agoric/kmarshal';
 import { setupTestLiveslots } from './liveslots-helpers.js';
 import { makeResolve, makeReject } from './util.js';
 
diff --git a/packages/swingset-liveslots/test/test-initial-vrefs.js b/packages/swingset-liveslots/test/test-initial-vrefs.js
index 65916a3d06b6..c53262d95ad9 100644
--- a/packages/swingset-liveslots/test/test-initial-vrefs.js
+++ b/packages/swingset-liveslots/test/test-initial-vrefs.js
@@ -1,9 +1,9 @@
 import test from 'ava';
 
 import { Far } from '@endo/far';
+import { kunser } from '@agoric/kmarshal';
 import { M } from '@agoric/store';
 import { setupTestLiveslots } from './liveslots-helpers.js';
-import { kunser } from './kmarshal.js';
 
 function buildRootObject(vatPowers, vatParameters, baggage) {
   const vd = vatPowers.VatData;
diff --git a/packages/swingset-liveslots/test/test-liveslots-mock-gc.js b/packages/swingset-liveslots/test/test-liveslots-mock-gc.js
index ad73d7d4dfd0..d7cff5d0967f 100644
--- a/packages/swingset-liveslots/test/test-liveslots-mock-gc.js
+++ b/packages/swingset-liveslots/test/test-liveslots-mock-gc.js
@@ -2,9 +2,9 @@
 import test from 'ava';
 
 import { Far } from '@endo/marshal';
+import { kslot, kser } from '@agoric/kmarshal';
 import { makeLiveSlots } from '../src/liveslots.js';
 import { parseVatSlot } from '../src/parseVatSlots.js';
-import { kslot, kser } from './kmarshal.js';
 import { buildSyscall } from './liveslots-helpers.js';
 import {
   makeMessage,
diff --git a/packages/swingset-liveslots/test/test-liveslots-real-gc.js b/packages/swingset-liveslots/test/test-liveslots-real-gc.js
index 0bb1c92389e2..97cbf33ce1d4 100644
--- a/packages/swingset-liveslots/test/test-liveslots-real-gc.js
+++ b/packages/swingset-liveslots/test/test-liveslots-real-gc.js
@@ -4,9 +4,9 @@ import test from 'ava';
 
 import { Far } from '@endo/marshal';
 import { makePromiseKit } from '@endo/promise-kit';
+import { kslot, kser } from '@agoric/kmarshal';
 import engineGC from './engine-gc.js';
 import { makeGcAndFinalize } from './gc-and-finalize.js';
-import { kslot, kser } from './kmarshal.js';
 import { buildSyscall, makeDispatch } from './liveslots-helpers.js';
 import {
   makeMessage,
diff --git a/packages/swingset-liveslots/test/test-liveslots.js b/packages/swingset-liveslots/test/test-liveslots.js
index 9bcb2fa9ae83..d926212eb862 100644
--- a/packages/swingset-liveslots/test/test-liveslots.js
+++ b/packages/swingset-liveslots/test/test-liveslots.js
@@ -5,9 +5,9 @@ import { E } from '@endo/eventual-send';
 import { Far } from '@endo/marshal';
 import { makePromiseKit } from '@endo/promise-kit';
 import { Fail } from '@agoric/assert';
+import { kslot, kser, kunser } from '@agoric/kmarshal';
 import { M } from '@agoric/store';
 import { makeLiveSlots, makeMarshaller } from '../src/liveslots.js';
-import { kslot, kser, kunser } from './kmarshal.js';
 import { buildSyscall, makeDispatch } from './liveslots-helpers.js';
 import { makeMessage, makeStartVat, makeResolve, makeReject } from './util.js';
 import { makeMockGC } from './mock-gc.js';
diff --git a/packages/swingset-liveslots/test/test-vpid-liveslots.js b/packages/swingset-liveslots/test/test-vpid-liveslots.js
index 2903c6bded58..0079e8c6a72e 100644
--- a/packages/swingset-liveslots/test/test-vpid-liveslots.js
+++ b/packages/swingset-liveslots/test/test-vpid-liveslots.js
@@ -3,11 +3,11 @@ import test from 'ava';
 
 import { E } from '@endo/eventual-send';
 import { makePromiseKit } from '@endo/promise-kit';
-import { Fail } from '@agoric/assert';
 import { Far } from '@endo/marshal';
+import { Fail } from '@agoric/assert';
+import { kser, kslot } from '@agoric/kmarshal';
 import { buildSyscall, makeDispatch } from './liveslots-helpers.js';
 import { makeMessage, makeResolve, makeReject } from './util.js';
-import { kser, kslot } from './kmarshal.js';
 
 function hush(p) {
   p.then(
diff --git a/packages/swingset-liveslots/test/util.js b/packages/swingset-liveslots/test/util.js
index 22af120c7ec5..a6f815964cc7 100644
--- a/packages/swingset-liveslots/test/util.js
+++ b/packages/swingset-liveslots/test/util.js
@@ -1,5 +1,5 @@
+import { kser } from '@agoric/kmarshal';
 import { vstr } from './vat-util.js';
-import { kser } from './kmarshal.js';
 
 export { vstr };
 
diff --git a/packages/swingset-liveslots/test/vat-util.js b/packages/swingset-liveslots/test/vat-util.js
index d88a807cd5cc..112205ab790c 100644
--- a/packages/swingset-liveslots/test/vat-util.js
+++ b/packages/swingset-liveslots/test/vat-util.js
@@ -2,7 +2,7 @@
 // modules
 
 import { Fail } from '@agoric/assert';
-import { kser, kunser } from './kmarshal.js';
+import { kser, kunser } from '@agoric/kmarshal';
 
 export function extractMessage(vatDeliverObject) {
   const [type, ...vdoargs] = vatDeliverObject;
diff --git a/packages/swingset-liveslots/test/virtual-objects/test-kind-changes.js b/packages/swingset-liveslots/test/virtual-objects/test-kind-changes.js
index 82b01ac24f17..7642eb3a43b2 100644
--- a/packages/swingset-liveslots/test/virtual-objects/test-kind-changes.js
+++ b/packages/swingset-liveslots/test/virtual-objects/test-kind-changes.js
@@ -1,10 +1,10 @@
 // @ts-nocheck
 import test from 'ava';
 import { Far } from '@endo/marshal';
+import { kser } from '@agoric/kmarshal';
 import { makeFakeVirtualStuff } from '../../tools/fakeVirtualSupport.js';
 import { makeLiveSlots } from '../../src/liveslots.js';
 import { parseVatSlot } from '../../src/parseVatSlots.js';
-import { kser } from '../kmarshal.js';
 import { buildSyscall } from '../liveslots-helpers.js';
 import { makeStartVat, makeMessage } from '../util.js';
 import { makeMockGC } from '../mock-gc.js';
diff --git a/packages/swingset-liveslots/test/virtual-objects/test-state-shape.js b/packages/swingset-liveslots/test/virtual-objects/test-state-shape.js
index c2891cbda8e4..7c9257ba1f62 100644
--- a/packages/swingset-liveslots/test/virtual-objects/test-state-shape.js
+++ b/packages/swingset-liveslots/test/virtual-objects/test-state-shape.js
@@ -2,9 +2,9 @@
 import test from 'ava';
 
 import { Far } from '@endo/marshal';
+import { kser, kslot } from '@agoric/kmarshal';
 import { M } from '@agoric/store';
 import { makeLiveSlots } from '../../src/liveslots.js';
-import { kser, kslot } from '../kmarshal.js';
 import { buildSyscall } from '../liveslots-helpers.js';
 import { makeStartVat, makeMessage } from '../util.js';
 import { makeMockGC } from '../mock-gc.js';
diff --git a/packages/swingset-liveslots/test/virtual-objects/test-virtualObjectGC.js b/packages/swingset-liveslots/test/virtual-objects/test-virtualObjectGC.js
index 14f9b3ec5927..2adf582af067 100644
--- a/packages/swingset-liveslots/test/virtual-objects/test-virtualObjectGC.js
+++ b/packages/swingset-liveslots/test/virtual-objects/test-virtualObjectGC.js
@@ -2,11 +2,11 @@
 import test from 'ava';
 
 import { Far } from '@endo/marshal';
+import { krefOf, kser, kslot } from '@agoric/kmarshal';
 import {
   setupTestLiveslots,
   findSyscallsByType,
 } from '../liveslots-helpers.js';
-import { krefOf, kser, kslot } from '../kmarshal.js';
 import { parseVatSlot } from '../../src/parseVatSlots.js';
 
 // Legs:
diff --git a/packages/swingset-liveslots/test/virtual-objects/test-virtualObjectManager.js b/packages/swingset-liveslots/test/virtual-objects/test-virtualObjectManager.js
index 86519f4fad1c..859d152bf96a 100644
--- a/packages/swingset-liveslots/test/virtual-objects/test-virtualObjectManager.js
+++ b/packages/swingset-liveslots/test/virtual-objects/test-virtualObjectManager.js
@@ -1,12 +1,12 @@
 // @ts-nocheck
 import test from 'ava';
 
+import { kser, kslot } from '@agoric/kmarshal';
 import {
   makeFakeVirtualObjectManager,
   makeFakeVirtualStuff,
 } from '../../tools/fakeVirtualSupport.js';
 
-import { kser, kslot } from '../kmarshal.js';
 import { vstr } from '../util.js';
 
 function initThing(label = 'thing', counter = 0) {
diff --git a/packages/swingset-liveslots/test/virtual-objects/test-vo-real-gc.js b/packages/swingset-liveslots/test/virtual-objects/test-vo-real-gc.js
index e4eadb938a2d..bf7283a7d20e 100644
--- a/packages/swingset-liveslots/test/virtual-objects/test-vo-real-gc.js
+++ b/packages/swingset-liveslots/test/virtual-objects/test-vo-real-gc.js
@@ -3,7 +3,7 @@
 import test from 'ava';
 
 import { Far } from '@endo/marshal';
-import { kser, kunser } from '../kmarshal.js';
+import { kser, kunser } from '@agoric/kmarshal';
 import { setupTestLiveslots } from '../liveslots-helpers.js';
 
 test('virtual object state writes', async t => {
diff --git a/packages/swingset-runner/demo/vatFailure/vat-bad.js b/packages/swingset-runner/demo/vatFailure/vat-bad.js
index 7ea8c6e058b3..bea73c6da989 100644
--- a/packages/swingset-runner/demo/vatFailure/vat-bad.js
+++ b/packages/swingset-runner/demo/vatFailure/vat-bad.js
@@ -1,5 +1,5 @@
 import { assert } from '@agoric/assert';
-import { kser } from '@agoric/swingset-vat/src/lib/kmarshal.js';
+import { kser } from '@agoric/kmarshal';
 
 export default function setup(syscall, _state, _helpers, _vatPowers) {
   function deliver(target, method, args) {
diff --git a/packages/swingset-runner/package.json b/packages/swingset-runner/package.json
index b590c20dde61..4fa77c6c5a86 100644
--- a/packages/swingset-runner/package.json
+++ b/packages/swingset-runner/package.json
@@ -24,6 +24,7 @@
     "@agoric/ertp": "^0.16.2",
     "@agoric/internal": "^0.3.2",
     "@agoric/inter-protocol": "^0.16.1",
+    "@agoric/kmarshal": "^0.1.0",
     "@agoric/stat-logger": "^0.4.28",
     "@agoric/store": "^0.9.2",
     "@agoric/swing-store": "^0.9.1",
diff --git a/packages/zoe/package.json b/packages/zoe/package.json
index 407d3ff0e462..a340ab3557d1 100644
--- a/packages/zoe/package.json
+++ b/packages/zoe/package.json
@@ -65,6 +65,7 @@
   },
   "devDependencies": {
     "@endo/init": "^0.5.59",
+    "@agoric/kmarshal": "^0.1.0",
     "ava": "^5.3.0",
     "c8": "^7.13.0",
     "import-meta-resolve": "^2.2.1",
diff --git a/packages/zoe/test/swingsetTests/zoe/test-zoe-upgrade.js b/packages/zoe/test/swingsetTests/zoe/test-zoe-upgrade.js
index 0acd57b2a222..226a2d1450a7 100644
--- a/packages/zoe/test/swingsetTests/zoe/test-zoe-upgrade.js
+++ b/packages/zoe/test/swingsetTests/zoe/test-zoe-upgrade.js
@@ -1,7 +1,7 @@
 import '@agoric/swingset-liveslots/tools/prepare-test-env.js';
 import test from 'ava';
 import { buildVatController } from '@agoric/swingset-vat';
-import { kunser } from '@agoric/swingset-vat/src/lib/kmarshal.js';
+import { kunser } from '@agoric/kmarshal';
 
 const bfile = name => new URL(name, import.meta.url).pathname;