diff --git a/packages/agoric-cli/package.json b/packages/agoric-cli/package.json
index 5786b3594f5..24b4f910ad6 100644
--- a/packages/agoric-cli/package.json
+++ b/packages/agoric-cli/package.json
@@ -69,6 +69,7 @@
     "@endo/patterns": "^1.4.0",
     "@endo/promise-kit": "^1.1.2",
     "@iarna/toml": "^2.2.3",
+    "@zip.js/zip.js": "^2.7.45",
     "anylogger": "^0.21.0",
     "chalk": "^5.2.0",
     "commander": "^11.1.0",
diff --git a/packages/agoric-cli/scripts/stat-bundle.js b/packages/agoric-cli/scripts/stat-bundle.js
new file mode 100755
index 00000000000..43de05222f7
--- /dev/null
+++ b/packages/agoric-cli/scripts/stat-bundle.js
@@ -0,0 +1,9 @@
+#!/usr/bin/env node
+import assert from 'node:assert';
+import process from 'node:process';
+import { statBundle } from '../src/lib/bundles.js';
+
+const filename = process.argv[2];
+assert(filename, 'usage: stat-bundle.js <filename>');
+
+await statBundle(filename);
diff --git a/packages/agoric-cli/scripts/stat-plans.js b/packages/agoric-cli/scripts/stat-plans.js
new file mode 100755
index 00000000000..34382985fba
--- /dev/null
+++ b/packages/agoric-cli/scripts/stat-plans.js
@@ -0,0 +1,5 @@
+#!/usr/bin/env node
+import process from 'node:process';
+import { statPlans } from '../src/lib/bundles.js';
+
+await statPlans(process.cwd());
diff --git a/packages/agoric-cli/src/lib/bundles.js b/packages/agoric-cli/src/lib/bundles.js
new file mode 100644
index 00000000000..d2519e26331
--- /dev/null
+++ b/packages/agoric-cli/src/lib/bundles.js
@@ -0,0 +1,89 @@
+/* global Buffer */
+
+import { BlobReader, TextWriter, ZipReader } from '@zip.js/zip.js'; // @endo/zip was tried but doesn't provide compressedSize
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import { join } from 'node:path';
+
+/** @import {Bundle} from '@agoric/swingset-vat'; */
+/** @import {CoreEvalPlan} from '@agoric/deploy-script-support/src/writeCoreEvalParts.js' */
+
+const PACKAGE_NAME_RE = /(?<packageName>.*-v[\d.]+)\//;
+
+/**
+ * @typedef CompartmentMap
+ * @property {string[]} tags
+ * @property {{compartment: string, module: string}} entry
+ * @property {Record<string, {name: string, label: string, location: string, modules: Record<string, {compartment: string, module: string}>}} compartments
+ */
+
+/** @param {Bundle} bundleObj*/
+export const extractBundleInfo = async bundleObj => {
+  await null;
+  if (bundleObj.moduleFormat === 'endoZipBase64') {
+    const contents = Buffer.from(bundleObj.endoZipBase64, 'base64');
+    const zipBlob = new Blob([contents], { type: 'application/zip' });
+
+    const zipFileReader = new BlobReader(zipBlob);
+    const writer = new TextWriter('utf-8');
+
+    const zipReader = new ZipReader(zipFileReader);
+    const entries = await zipReader.getEntries();
+    await zipReader.close();
+
+    assert(entries[0].filename, 'compartment-map.json');
+    const cmapStr = await entries[0].getData(writer);
+    /** @type {CompartmentMap} */
+    const compartmentMap = JSON.parse(cmapStr);
+
+    const fileSizes = Object.fromEntries(
+      entries.map(e => [e.filename, e.compressedSize]),
+    );
+
+    return { compartmentMap, fileSizes };
+  }
+};
+
+// UNTIL https://github.com/endojs/endo/issues/1656
+/** @param {string} bundleFilename */
+export const statBundle = async bundleFilename => {
+  const bundle = fs.readFileSync(bundleFilename, 'utf8');
+  /** @type {Bundle} */
+  const bundleObj = JSON.parse(bundle);
+  console.log('\nBUNDLE', bundleObj.moduleFormat, bundleFilename);
+
+  const info = await extractBundleInfo(bundleObj);
+
+  /** @type {Record<string, number>} */
+  const byPackage = {};
+  let totalSize = 0;
+  for (const [filename, size] of Object.entries(info.fileSizes)) {
+    totalSize += size;
+    if (filename === 'compartment-map.json') {
+      continue;
+    }
+    const { packageName } = filename.match(PACKAGE_NAME_RE).groups;
+    byPackage[packageName] ||= 0;
+    byPackage[packageName] += size;
+  }
+
+  console.log('Sum of compressed file sizes in each package:');
+  console.table(byPackage);
+
+  console.log('total size:', totalSize);
+};
+
+/** @param {string} path */
+export const statPlans = async path => {
+  const files = await fs.promises.readdir(path);
+  const planfiles = files.filter(f => f.endsWith('plan.json'));
+
+  for (const planfile of planfiles) {
+    /** @type {CoreEvalPlan} */
+    const plan = JSON.parse(fs.readFileSync(join(path, planfile), 'utf8'));
+    console.log('\n**\nPLAN', plan.name);
+    for (const bundle of plan.bundles) {
+      await statBundle(bundle.fileName);
+    }
+  }
+};
diff --git a/yarn.lock b/yarn.lock
index 2f68ae27e00..508f05a21f4 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3785,6 +3785,11 @@
     js-yaml "^3.10.0"
     tslib "^2.4.0"
 
+"@zip.js/zip.js@^2.7.45":
+  version "2.7.45"
+  resolved "https://registry.yarnpkg.com/@zip.js/zip.js/-/zip.js-2.7.45.tgz#823fe2789401d8c1d836ce866578379ec1bd6f0b"
+  integrity sha512-Mm2EXF33DJQ/3GWWEWeP1UCqzpQ5+fiMvT3QWspsXY05DyqqxWu7a9awSzU4/spHMHVFrTjani1PR0vprgZpow==
+
 "@zkochan/js-yaml@0.0.6":
   version "0.0.6"
   resolved "https://registry.yarnpkg.com/@zkochan/js-yaml/-/js-yaml-0.0.6.tgz#975f0b306e705e28b8068a07737fa46d3fc04826"