diff --git a/packages/cosmic-swingset/Makefile b/packages/cosmic-swingset/Makefile
index 312a0194f4b..e33a171b8ff 100644
--- a/packages/cosmic-swingset/Makefile
+++ b/packages/cosmic-swingset/Makefile
@@ -101,9 +101,10 @@ t1-start-ag-solo:
 #
 # If you still want the client/chain separation without delay,
 # then run: make scenario3-setup FAKE_CHAIN_DELAY=0
+VATWORKER=local
 scenario3-setup:
 	rm -rf t3
-	bin/ag-solo init t3 --egresses=fake --webport=$(BASE_PORT)
+	bin/ag-solo init t3 --egresses=fake --webport=$(BASE_PORT) --defaultManagerType=$(VATWORKER)
 	@echo 'Execute `make scenario3-run` to run the client and simulated chain'
 
 # This runs both the client and the fake chain.
diff --git a/packages/cosmic-swingset/lib/ag-solo/init-basedir.js b/packages/cosmic-swingset/lib/ag-solo/init-basedir.js
index e489d207252..a186e85c87b 100644
--- a/packages/cosmic-swingset/lib/ag-solo/init-basedir.js
+++ b/packages/cosmic-swingset/lib/ag-solo/init-basedir.js
@@ -1,4 +1,4 @@
-/* global __dirname Buffer */
+/* global __dirname Buffer process */
 import fs from 'fs';
 import path from 'path';
 import { execFileSync } from 'child_process';
@@ -18,8 +18,14 @@ export default function initBasedir(
   egresses,
   opts = {},
 ) {
-  const { wallet = DEFAULT_WALLET, ...options } = opts;
+  const { env = process.environment } = opts;
+  const {
+    wallet = DEFAULT_WALLET,
+    defaultManagerType = env.WORKER_TYPE || 'local',
+    ...options
+  } = opts;
   options.wallet = wallet;
+  options.defaultManagerType = defaultManagerType;
 
   const here = __dirname;
   // We either need a basedir with an initialised key, or no basedir.
diff --git a/packages/cosmic-swingset/lib/ag-solo/main.js b/packages/cosmic-swingset/lib/ag-solo/main.js
index 60bbeb77830..1b9dd2971f8 100644
--- a/packages/cosmic-swingset/lib/ag-solo/main.js
+++ b/packages/cosmic-swingset/lib/ag-solo/main.js
@@ -78,6 +78,7 @@ start
           webport: '8000',
           webhost: '127.0.0.1',
           egresses: DEFAULT_EGRESSES,
+          defaultManagerType: process.env.WORKER_TYPE || 'local',
         },
       });
       const webport = Number(subOpts.webport);
diff --git a/packages/cosmic-swingset/lib/ag-solo/start.js b/packages/cosmic-swingset/lib/ag-solo/start.js
index dbdd598ea96..7eb8694044e 100644
--- a/packages/cosmic-swingset/lib/ag-solo/start.js
+++ b/packages/cosmic-swingset/lib/ag-solo/start.js
@@ -81,6 +81,7 @@ async function buildSwingset(
   vatsDir,
   argv,
   broadcast,
+  defaultManagerType,
 ) {
   const initialMailboxState = JSON.parse(fs.readFileSync(mailboxStateFile));
 
@@ -143,6 +144,9 @@ async function buildSwingset(
   const { storage, commit } = openSwingStore(kernelStateDBDir);
 
   if (!swingsetIsInitialized(storage)) {
+    if (defaultManagerType && !config.defaultManagerType) {
+      config.defaultManagerType = defaultManagerType;
+    }
     await initializeSwingset(config, argv, storage);
   }
   const controller = await makeSwingsetController(storage, deviceEndowments);
@@ -277,6 +281,10 @@ export default async function start(basedir, argv) {
     }
   }
 
+  const { wallet, defaultManagerType } = JSON.parse(
+    fs.readFileSync('options.json', 'utf-8'),
+  );
+
   const vatsDir = path.join(basedir, 'vats');
   const stateDBDir = path.join(basedir, 'swingset-kernel-state');
   const d = await buildSwingset(
@@ -285,6 +293,7 @@ export default async function start(basedir, argv) {
     vatsDir,
     argv,
     broadcast,
+    defaultManagerType,
   );
 
   const {
@@ -298,8 +307,6 @@ export default async function start(basedir, argv) {
   // Remove wallet traces.
   await unlink('html/wallet').catch(_ => {});
 
-  const { wallet } = JSON.parse(fs.readFileSync('options.json', 'utf-8'));
-
   // Symlink the wallet.
   const pjs = require.resolve(`${wallet}/package.json`);
   const {