diff --git a/package.json b/package.json
index fbfa4c8b59b..633debfc2f2 100644
--- a/package.json
+++ b/package.json
@@ -15,6 +15,7 @@
     "packages/bundle-source",
     "packages/import-bundle",
     "packages/eventual-send",
+    "packages/governance",
     "packages/promise-kit",
     "packages/tame-metering",
     "packages/transform-metering",
diff --git a/packages/governance/CHANGELOG.md b/packages/governance/CHANGELOG.md
new file mode 100644
index 00000000000..767840ada8e
--- /dev/null
+++ b/packages/governance/CHANGELOG.md
@@ -0,0 +1,5 @@
+# Change Log
+
+All notable changes to this project will be documented in this file.
+See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
+
diff --git a/packages/governance/NEWS.md b/packages/governance/NEWS.md
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/packages/governance/jsconfig.json b/packages/governance/jsconfig.json
new file mode 100644
index 00000000000..195554cb5e5
--- /dev/null
+++ b/packages/governance/jsconfig.json
@@ -0,0 +1,18 @@
+// This file can contain .js-specific Typescript compiler config.
+{
+  "compilerOptions": {
+    "target": "esnext",
+
+    "noEmit": true,
+/*
+    // The following flags are for creating .d.ts files:
+    "noEmit": false,
+    "declaration": true,
+    "emitDeclarationOnly": true,
+*/
+    "downlevelIteration": true,
+    "strictNullChecks": true,
+    "moduleResolution": "node",
+  },
+  "include": ["src/**/*.js", "test/**/*.js", "exported.js", "globals.d.ts"],
+}
diff --git a/packages/governance/package.json b/packages/governance/package.json
new file mode 100644
index 00000000000..bdebba1b597
--- /dev/null
+++ b/packages/governance/package.json
@@ -0,0 +1,83 @@
+{
+  "name": "@agoric/governance",
+  "version": "0.1.0",
+  "description": "Core governance support",
+  "parsers": {
+    "js": "mjs"
+  },
+  "main": "src/missing.js",
+  "engines": {
+    "node": ">=11.0"
+  },
+  "scripts": {
+    "build": "exit 0",
+    "test": "ava",
+    "test:xs": "exit 0",
+    "lint-fix": "yarn lint:eslint --fix && yarn lint:types",
+    "lint-check": "yarn lint",
+    "lint": "yarn lint:types && yarn lint:eslint",
+    "lint:eslint": "eslint '**/*.js'",
+    "lint:types": "tsc -p jsconfig.json"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/Agoric/agoric-sdk.git"
+  },
+  "author": "Agoric",
+  "license": "Apache-2.0",
+  "bugs": {
+    "url": "https://github.com/Agoric/agoric-sdk/issues"
+  },
+  "homepage": "https://github.com/Agoric/agoric-sdk#readme",
+  "dependencies": {
+    "@agoric/assert": "^0.2.12",
+    "@agoric/bundle-source": "^1.3.7",
+    "@agoric/captp": "^1.7.13",
+    "@agoric/deploy-script-support": "^0.2.9",
+    "@agoric/ertp": "^0.11.2",
+    "@agoric/eventual-send": "^0.13.14",
+    "@agoric/marshal": "^0.4.11",
+    "@agoric/nat": "^4.0.0",
+    "@agoric/notifier": "^0.3.14",
+    "@agoric/promise-kit": "^0.2.13",
+    "@agoric/store": "^0.4.14",
+    "@agoric/swingset-vat": "^0.17.2",
+    "@agoric/zoe": "^0.15.7"
+  },
+  "devDependencies": {
+    "@agoric/install-ses": "^0.5.13",
+    "ava": "^3.12.1",
+    "esm": "^3.2.25",
+    "ses": "^0.12.7"
+  },
+  "files": [
+    "bundles/",
+    "src/",
+    "exported.js",
+    "NEWS.md"
+  ],
+  "ava": {
+    "files": [
+      "test/**/test-*.js"
+    ],
+    "require": [
+      "esm"
+    ],
+    "timeout": "10m"
+  },
+  "eslintConfig": {
+    "extends": [
+      "@agoric"
+    ]
+  },
+  "eslintIgnore": [
+    "bundle-*.js"
+  ],
+  "prettier": {
+    "trailingComma": "all",
+    "singleQuote": true
+  },
+  "publishConfig": {
+    "access": "public"
+  }
+}
diff --git a/packages/governance/src/param-manager.js b/packages/governance/src/param-manager.js
new file mode 100644
index 00000000000..b06771ea882
--- /dev/null
+++ b/packages/governance/src/param-manager.js
@@ -0,0 +1,93 @@
+// @ts-check
+
+import { makeStore } from '@agoric/store';
+import { assert, details as X } from '@agoric/assert';
+import { Nat } from '@agoric/nat';
+import { assertIsRatio } from '@agoric/zoe/src/contractSupport';
+import { AmountMath, looksLikeBrand } from '@agoric/ertp';
+
+const ParamType = {
+  NAT: 'nat',
+  BIGINT: 'bigint',
+  STRING: 'string',
+  RATIO: 'ratio',
+  AMOUNT: 'amount',
+  BRAND: 'brand',
+};
+harden(ParamType);
+
+function assertType(type, value, name) {
+  if (!type) {
+    // undefined type means don't verify. Did we omit an interesting type?
+    return;
+  }
+
+  switch (type) {
+    case ParamType.NAT:
+      Nat(value);
+      break;
+    case ParamType.BIGINT:
+      assert.typeof(value, 'bigint');
+      break;
+    case ParamType.STRING:
+      assert.typeof(value, 'string');
+      break;
+    case ParamType.RATIO:
+      assertIsRatio(value);
+      break;
+    case ParamType.AMOUNT:
+      // TODO(hibbert): is there a clean way to assert something is an amount?
+      // An alternate approach would be to say the contract knows the brand and
+      // the managed parameter only needs to supply the value.
+      assert(
+        AmountMath.isEqual(value, value),
+        X`value for ${name} must be an Amount, was ${value}`,
+      );
+      break;
+    case ParamType.BRAND:
+      assert(
+        looksLikeBrand(value),
+        X`value for ${name} must be a brand, was ${value}`,
+      );
+      break;
+    default:
+      assert.fail(X`unknown type guard ${type}`);
+  }
+}
+
+function parse(paramDesc) {
+  const bindings = makeStore('name');
+  const types = makeStore('name');
+
+  paramDesc.forEach(({ name, value, type }) => {
+    assert.typeof(name, 'string');
+    assertType(type, value, name);
+    bindings.init(name, value);
+    types.init(name, type);
+  });
+
+  return { bindings, types };
+}
+
+/** @type {BuildParamManager} */
+function buildParamManager(paramDesc) {
+  const { bindings, types } = parse(paramDesc);
+
+  const publicFacet = {
+    lookup(name) {
+      return bindings.get(name);
+    },
+  };
+
+  const manager = {
+    update(name, value) {
+      assertType(types.get(name), value, name);
+      bindings.set(name, value);
+    },
+  };
+
+  return { publicFacet, manager };
+}
+harden(buildParamManager);
+
+export { ParamType, buildParamManager };
diff --git a/packages/governance/src/types.js b/packages/governance/src/types.js
new file mode 100644
index 00000000000..0521a569f59
--- /dev/null
+++ b/packages/governance/src/types.js
@@ -0,0 +1,34 @@
+// @ts-check
+
+/**
+ * @typedef {'nat' | 'bigint' | 'string' | 'ratio' | 'amount' | 'brand' } ParamType
+ */
+
+/**
+ * @typedef  {Object} ParamManager
+ * @property {(name: string, value: any) => void} update
+ */
+
+/**
+ * @typedef  {Object} ParamManagerPublic
+ * @property {(name: string) => any} lookup
+ */
+
+/**
+ * @typedef  {{name: string,
+ *             value: any,
+ *             type: string,
+ *             }} ParamDescription
+ */
+
+// type: string above should be type: ParamType
+
+/**
+ * @typedef {Array<ParamDescription>} ParamDescriptions
+ */
+
+/**
+ * @callback BuildParamManager
+ * @param {ParamDescriptions} paramDesc
+ * @returns {{publicFacet: ParamManagerPublic, manager: ParamManager }}
+ */
diff --git a/packages/governance/test/test-param-manager.js b/packages/governance/test/test-param-manager.js
new file mode 100644
index 00000000000..60c3dfd3bab
--- /dev/null
+++ b/packages/governance/test/test-param-manager.js
@@ -0,0 +1,163 @@
+// @ts-check
+
+import { test } from '@agoric/zoe/tools/prepare-test-env-ava';
+import '@agoric/zoe/exported';
+import { AmountMath, AssetKind, makeIssuerKit } from '@agoric/ertp';
+import { makeRatio } from '@agoric/zoe/src/contractSupport';
+
+import { buildParamManager, ParamType } from '../src/param-manager';
+
+const BASIS_POINTS = 10_000;
+
+test('params one Nat', async t => {
+  const { publicFacet, manager } = buildParamManager([
+    {
+      name: 'number',
+      value: 13,
+      type: ParamType.NAT,
+    },
+  ]);
+  t.is(publicFacet.lookup('number'), 13);
+  manager.update('number', 42);
+  t.is(publicFacet.lookup('number'), 42);
+
+  t.throws(
+    () => manager.update('string', 'foo'),
+    {
+      message: '"name" not found: "string"',
+    },
+    '"string" was not a registered name',
+  );
+  t.throws(
+    () => manager.update('number', 18.1),
+    {
+      message: '18.1 not a safe integer',
+    },
+    'value should be a nat',
+  );
+});
+
+test('params one String', async t => {
+  const { publicFacet, manager } = buildParamManager([
+    {
+      name: 'string',
+      value: 'foo',
+      type: ParamType.STRING,
+    },
+  ]);
+  t.is(publicFacet.lookup('string'), 'foo');
+  manager.update('string', 'bar');
+  t.is(publicFacet.lookup('string'), 'bar');
+
+  t.throws(
+    () => manager.update('number', 'foo'),
+    {
+      message: '"name" not found: "number"',
+    },
+    '"number" was not a registered name',
+  );
+  t.throws(
+    () => manager.update('string', 18.1),
+    {
+      message: '18.1 must be a string',
+    },
+    'value should be a string',
+  );
+});
+
+test('params one Amount', async t => {
+  const { brand } = makeIssuerKit('roses', AssetKind.SET);
+  const { publicFacet, manager } = buildParamManager([
+    {
+      name: 'amount',
+      value: AmountMath.makeEmpty(brand),
+      type: ParamType.AMOUNT,
+    },
+  ]);
+  t.deepEqual(publicFacet.lookup('amount'), AmountMath.makeEmpty(brand));
+  manager.update('amount', AmountMath.make(brand, [13]));
+  t.deepEqual(publicFacet.lookup('amount'), AmountMath.make(brand, [13]));
+
+  t.throws(
+    () => manager.update('number', 13),
+    {
+      message: '"name" not found: "number"',
+    },
+    '"number" was not a registered name',
+  );
+
+  t.throws(
+    () => manager.update('amount', 18.1),
+    {
+      message:
+        "The amount 18.1 doesn't look like an amount. Did you pass a value instead?",
+    },
+    'value should be a amount',
+  );
+});
+
+test('params one BigInt', async t => {
+  const { publicFacet, manager } = buildParamManager([
+    {
+      name: 'bigint',
+      value: 314159n,
+      type: ParamType.BIGINT,
+    },
+  ]);
+  t.deepEqual(publicFacet.lookup('bigint'), 314159n);
+  manager.update('bigint', 271828182845904523536n);
+  t.deepEqual(publicFacet.lookup('bigint'), 271828182845904523536n);
+
+  t.throws(
+    () => manager.update('bigint', 18.1),
+    {
+      message: '18.1 must be a bigint',
+    },
+    'value should be a bigint',
+  );
+});
+
+test('params one ratio', async t => {
+  const { brand } = makeIssuerKit('roses', AssetKind.SET);
+  const { publicFacet, manager } = buildParamManager([
+    {
+      name: 'ratio',
+      value: makeRatio(7, brand),
+      type: ParamType.RATIO,
+    },
+  ]);
+  t.deepEqual(publicFacet.lookup('ratio'), makeRatio(7, brand));
+  manager.update('ratio', makeRatio(701, brand, BASIS_POINTS));
+  t.deepEqual(publicFacet.lookup('ratio'), makeRatio(701, brand, BASIS_POINTS));
+
+  t.throws(
+    () => manager.update('ratio', 18.1),
+    {
+      message: 'Ratio 18.1 must be a record with 2 fields.',
+    },
+    'value should be a ratio',
+  );
+});
+
+test('params one brand', async t => {
+  const { brand: roseBrand } = makeIssuerKit('roses', AssetKind.SET);
+  const { brand: thornBrand } = makeIssuerKit('thorns');
+  const { publicFacet, manager } = buildParamManager([
+    {
+      name: 'brand',
+      value: roseBrand,
+      type: ParamType.BRAND,
+    },
+  ]);
+  t.deepEqual(publicFacet.lookup('brand'), roseBrand);
+  manager.update('brand', thornBrand);
+  t.deepEqual(publicFacet.lookup('brand'), thornBrand);
+
+  t.throws(
+    () => manager.update('brand', 18.1),
+    {
+      message: 'value for "brand" must be a brand, was 18.1',
+    },
+    'value should be a brand',
+  );
+});