diff --git a/OpenJSFoundation/draft04/official-ajv-draft-04-meta-schema/README.md b/OpenJSFoundation/draft04/official-ajv-draft-04-meta-schema/README.md
new file mode 100644
index 0000000..4e85f19
--- /dev/null
+++ b/OpenJSFoundation/draft04/official-ajv-draft-04-meta-schema/README.md
@@ -0,0 +1,19 @@
+# official-ajv-draft-04-meta-schema
+
+## What this file is
+
+`official-ajv-draft-04-meta-schema.json` is the canonical JSON Schema draft-04 meta-schema — the schema that describes what a valid draft-04 JSON Schema looks like. It is sourced from the `ajv-draft-04` npm package (`node_modules/ajv-draft-04/dist/refs/json-schema-draft-04.json`), which itself mirrors the official specification document published by the JSON Schema organization.
+
+## Why it exists here
+
+`@adobe/reactor-validator` uses AJV v8 to validate Tags extension descriptors against the turbine platform schemas (`@adobe/reactor-turbine-schemas`). Those schemas declare `"$schema": "http://json-schema.org/draft-04/schema#"`, meaning they are draft-04 JSON Schemas.
+
+AJV v8 ships meta-schemas for draft-06, draft-07, draft 2019-09, and draft 2020-12 — but not draft-04. Previously, the `ajv-draft-04` package was used as a dependency to supply both the draft-04 vocabulary and this meta-schema. That package declares `ajv@^8` as an optional peer dependency, which causes a runtime resolution failure for downstream consumers: npm nests `ajv@8` under this package's own `node_modules`, while `ajv-draft-04` gets hoisted to the consumer's top-level `node_modules` and resolves `require('ajv/dist/core')` against whatever AJV version the consumer has installed — which may be v6.
+
+To eliminate that broken dependency chain, `ajv-draft-04` was removed and AJV v8 is now configured directly. This file provides the draft-04 meta-schema so AJV can validate that the turbine platform schemas are well-formed draft-04 schemas at compile time, preserving the same correctness guarantees as before.
+
+## Source
+
+- npm package: `ajv-draft-04` (any version)
+- path within package: `dist/refs/json-schema-draft-04.json`
+- upstream specification: http://json-schema.org/draft-04/schema
diff --git a/OpenJSFoundation/draft04/official-ajv-draft-04-meta-schema/official-ajv-draft-04-meta-schema.json b/OpenJSFoundation/draft04/official-ajv-draft-04-meta-schema/official-ajv-draft-04-meta-schema.json
new file mode 100644
index 0000000..d96222e
--- /dev/null
+++ b/OpenJSFoundation/draft04/official-ajv-draft-04-meta-schema/official-ajv-draft-04-meta-schema.json
@@ -0,0 +1,138 @@
+{
+  "id": "http://json-schema.org/draft-04/schema#",
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "description": "Core schema meta-schema",
+  "definitions": {
+    "schemaArray": {
+      "type": "array",
+      "minItems": 1,
+      "items": {"$ref": "#"}
+    },
+    "positiveInteger": {
+      "type": "integer",
+      "minimum": 0
+    },
+    "positiveIntegerDefault0": {
+      "allOf": [{"$ref": "#/definitions/positiveInteger"}, {"default": 0}]
+    },
+    "simpleTypes": {
+      "enum": ["array", "boolean", "integer", "null", "number", "object", "string"]
+    },
+    "stringArray": {
+      "type": "array",
+      "items": {"type": "string"},
+      "minItems": 1,
+      "uniqueItems": true
+    }
+  },
+  "type": "object",
+  "properties": {
+    "id": {
+      "type": "string",
+      "format": "uri"
+    },
+    "$schema": {
+      "type": "string",
+      "format": "uri"
+    },
+    "title": {
+      "type": "string"
+    },
+    "description": {
+      "type": "string"
+    },
+    "default": {},
+    "multipleOf": {
+      "type": "number",
+      "minimum": 0,
+      "exclusiveMinimum": true
+    },
+    "maximum": {
+      "type": "number"
+    },
+    "exclusiveMaximum": {
+      "type": "boolean",
+      "default": false
+    },
+    "minimum": {
+      "type": "number"
+    },
+    "exclusiveMinimum": {
+      "type": "boolean",
+      "default": false
+    },
+    "maxLength": {"$ref": "#/definitions/positiveInteger"},
+    "minLength": {"$ref": "#/definitions/positiveIntegerDefault0"},
+    "pattern": {
+      "type": "string",
+      "format": "regex"
+    },
+    "additionalItems": {
+      "anyOf": [{"type": "boolean"}, {"$ref": "#"}],
+      "default": {}
+    },
+    "items": {
+      "anyOf": [{"$ref": "#"}, {"$ref": "#/definitions/schemaArray"}],
+      "default": {}
+    },
+    "maxItems": {"$ref": "#/definitions/positiveInteger"},
+    "minItems": {"$ref": "#/definitions/positiveIntegerDefault0"},
+    "uniqueItems": {
+      "type": "boolean",
+      "default": false
+    },
+    "maxProperties": {"$ref": "#/definitions/positiveInteger"},
+    "minProperties": {"$ref": "#/definitions/positiveIntegerDefault0"},
+    "required": {"$ref": "#/definitions/stringArray"},
+    "additionalProperties": {
+      "anyOf": [{"type": "boolean"}, {"$ref": "#"}],
+      "default": {}
+    },
+    "definitions": {
+      "type": "object",
+      "additionalProperties": {"$ref": "#"},
+      "default": {}
+    },
+    "properties": {
+      "type": "object",
+      "additionalProperties": {"$ref": "#"},
+      "default": {}
+    },
+    "patternProperties": {
+      "type": "object",
+      "additionalProperties": {"$ref": "#"},
+      "default": {}
+    },
+    "dependencies": {
+      "type": "object",
+      "additionalProperties": {
+        "anyOf": [{"$ref": "#"}, {"$ref": "#/definitions/stringArray"}]
+      }
+    },
+    "enum": {
+      "type": "array",
+      "minItems": 1,
+      "uniqueItems": true
+    },
+    "type": {
+      "anyOf": [
+        {"$ref": "#/definitions/simpleTypes"},
+        {
+          "type": "array",
+          "items": {"$ref": "#/definitions/simpleTypes"},
+          "minItems": 1,
+          "uniqueItems": true
+        }
+      ]
+    },
+    "allOf": {"$ref": "#/definitions/schemaArray"},
+    "anyOf": {"$ref": "#/definitions/schemaArray"},
+    "oneOf": {"$ref": "#/definitions/schemaArray"},
+    "not": {"$ref": "#"}
+  },
+  "dependencies": {
+    "exclusiveMaximum": ["maximum"],
+    "exclusiveMinimum": ["minimum"]
+  },
+  "default": {}
+}
diff --git a/lib/createDraft4Ajv.js b/lib/createDraft4Ajv.js
new file mode 100644
index 0000000..95bd9d4
--- /dev/null
+++ b/lib/createDraft4Ajv.js
@@ -0,0 +1,133 @@
+/***************************************************************************************
+ * (c) 2017 Adobe. All rights reserved.
+ * This file is licensed to you under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under
+ * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+ * OF ANY KIND, either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ ****************************************************************************************/
+
+// Factory that creates an AJV v8 instance configured for JSON Schema draft-04.
+//
+// AJV v8 speaks draft-07 natively and does not ship a draft-04 meta-schema. This module
+// replicates what the ajv-draft-04 package provided, using only ajv's own internal modules,
+// so downstream consumers are not exposed to ajv-draft-04's broken optional peer-dependency
+// chain (see: https://github.com/adobe/reactor-validator/issues/XX).
+
+'use strict';
+var _ajvCore = require('ajv/dist/core');
+var AjvCore = _ajvCore.default;
+var _ = _ajvCore._;
+var str = _ajvCore.str;
+var ops = require('ajv/dist/compile/codegen').operators;
+var addAJVFormats = require('ajv-formats');
+var draft4MetaSchema = require('../OpenJSFoundation/draft04/official-ajv-draft-04-meta-schema/official-ajv-draft-04-meta-schema.json');
+
+var DRAFT4_META_SCHEMA_ID = 'http://json-schema.org/draft-04/schema';
+
+// JSON Schema draft-04 and draft-07 express "exclusive" range limits differently:
+//
+//   draft-04: two keywords — a numeric "minimum" plus a boolean flag "exclusiveMinimum: true"
+//             e.g. { "minimum": 0, "exclusiveMinimum": true } means value must be > 0
+//
+//   draft-07: one keyword — "exclusiveMinimum" is itself the numeric limit
+//             e.g. { "exclusiveMinimum": 0 } means value must be > 0
+//
+// AJV v8 speaks draft-07 natively, so it expects exclusiveMinimum/exclusiveMaximum to always
+// be numbers. The draft-04 meta-schema we register (so AJV can validate that the turbine platform
+// schemas are well-formed draft-04) uses the boolean flag style internally. Without custom
+// handlers, AJV v8 throws "exclusiveMinimum value must be [number]" when it tries to compile
+// that meta-schema.
+//
+// limitNumberDraft4 replaces AJV v8's built-in limitNumber. It handles "minimum"/"maximum" as
+// numeric keywords but peeks at the parent schema for a boolean exclusiveMinimum/exclusiveMaximum
+// flag, switching between strict (>) and non-strict (>=) comparisons accordingly.
+//
+// limitNumberExclusiveDraft4 registers "exclusiveMinimum"/"exclusiveMaximum" as valid boolean
+// keywords so AJV does not reject them. It generates no data-validation code — the actual
+// comparison logic lives in limitNumberDraft4 above.
+var LIMIT_KWDS = {
+  maximum: {
+    exclusive: 'exclusiveMaximum',
+    ops: [
+      { okStr: '<=', ok: ops.LTE, fail: ops.GT },
+      { okStr: '<',  ok: ops.LT,  fail: ops.GTE },
+    ],
+  },
+  minimum: {
+    exclusive: 'exclusiveMinimum',
+    ops: [
+      { okStr: '>=', ok: ops.GTE, fail: ops.LT },
+      { okStr: '>',  ok: ops.GT,  fail: ops.LTE },
+    ],
+  },
+};
+
+function kwdOp(cxt) {
+  var kwd = LIMIT_KWDS[cxt.keyword];
+  var opsIdx = (cxt.parentSchema && cxt.parentSchema[kwd.exclusive]) ? 1 : 0;
+  return kwd.ops[opsIdx];
+}
+
+var limitNumberDraft4 = {
+  keyword: Object.keys(LIMIT_KWDS),
+  type: 'number',
+  schemaType: 'number',
+  $data: true,
+  error: {
+    message: function(cxt) { return str`must be ${kwdOp(cxt).okStr} ${cxt.schemaCode}`; },
+    params:  function(cxt) { return _`{comparison: ${kwdOp(cxt).okStr}, limit: ${cxt.schemaCode}}`; },
+  },
+  code: function(cxt) {
+    cxt.fail$data(_`${cxt.data} ${kwdOp(cxt).fail} ${cxt.schemaCode} || isNaN(${cxt.data})`);
+  },
+};
+
+var limitNumberExclusiveDraft4 = {
+  keyword: ['exclusiveMaximum', 'exclusiveMinimum'],
+  type: 'number',
+  schemaType: 'boolean',
+  code: function(cxt) {
+    var paired = { exclusiveMaximum: 'maximum', exclusiveMinimum: 'minimum' };
+    if (cxt.parentSchema[paired[cxt.keyword]] === undefined) {
+      throw new Error(cxt.keyword + ' can only be used with ' + paired[cxt.keyword]);
+    }
+  },
+};
+
+var draft4CoreVocab = [
+  '$schema', 'id', '$defs', '$comment', 'definitions',
+  require('ajv/dist/vocabularies/core/ref').default,
+];
+
+var draft4ValidationVocab = [
+  limitNumberDraft4,
+  limitNumberExclusiveDraft4,
+  require('ajv/dist/vocabularies/validation/multipleOf').default,
+  require('ajv/dist/vocabularies/validation/limitLength').default,
+  require('ajv/dist/vocabularies/validation/pattern').default,
+  require('ajv/dist/vocabularies/validation/limitProperties').default,
+  require('ajv/dist/vocabularies/validation/required').default,
+  require('ajv/dist/vocabularies/validation/limitItems').default,
+  require('ajv/dist/vocabularies/validation/uniqueItems').default,
+  { keyword: 'type', schemaType: ['string', 'array'] },
+  { keyword: 'nullable', schemaType: 'boolean' },
+  require('ajv/dist/vocabularies/validation/const').default,
+  require('ajv/dist/vocabularies/validation/enum').default,
+];
+
+module.exports = function createDraft4Ajv() {
+  var ajv = new AjvCore({ schemaId: 'id', strict: false, defaultMeta: DRAFT4_META_SCHEMA_ID });
+  ajv.addVocabulary(draft4CoreVocab);
+  ajv.addVocabulary(draft4ValidationVocab);
+  ajv.addVocabulary(require('ajv/dist/vocabularies/applicator').default());
+  ajv.addVocabulary(require('ajv/dist/vocabularies/format').default);
+  ajv.addVocabulary(['title', 'description', 'default']);
+  ajv.addMetaSchema(draft4MetaSchema, DRAFT4_META_SCHEMA_ID, false);
+  ajv.refs['http://json-schema.org/schema'] = DRAFT4_META_SCHEMA_ID;
+  addAJVFormats(ajv);
+  return ajv;
+};
diff --git a/lib/validateSchema.js b/lib/validateSchema.js
index 01ee3db..821bd5a 100644
--- a/lib/validateSchema.js
+++ b/lib/validateSchema.js
@@ -15,8 +15,7 @@
 // Returns undefined if valid, or an error string if not.
 
 'use strict';
-var Ajv = require("ajv-draft-04");
-var addAJVFormats = require("ajv-formats");
+var createDraft4Ajv = require('./createDraft4Ajv');
 
 var schemas = {
   web: require('@adobe/reactor-turbine-schemas/schemas/extension-package-web.json'),
@@ -24,6 +23,8 @@ var schemas = {
   mobile: require('@adobe/reactor-turbine-schemas/schemas/extension-package-mobile.json')
 };
 
+var ajv = createDraft4Ajv();
+
 var validateJsonStructure = function(extensionDescriptor) {
   var platform = extensionDescriptor.platform;
   if (!platform) {
@@ -33,8 +34,6 @@ var validateJsonStructure = function(extensionDescriptor) {
   if (!extensionDescriptorSchema) {
     return 'unknown platform "' + platform + '".';
   }
-  var ajv = new Ajv({ schemaId: 'auto', strict: false });
-  addAJVFormats(ajv);
   if (!ajv.validate(extensionDescriptorSchema, extensionDescriptor)) {
     return ajv.errorsText();
   }
diff --git a/package-lock.json b/package-lock.json
index c8bbbec..5e5ec04 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,17 +1,16 @@
 {
   "name": "@adobe/reactor-validator",
-  "version": "3.0.0",
+  "version": "3.1.0-beta.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@adobe/reactor-validator",
-      "version": "3.0.0",
+      "version": "3.1.0-beta.1",
       "license": "Apache-2.0",
       "dependencies": {
         "@adobe/reactor-turbine-schemas": "^10.8.0",
         "ajv": "^8.12.0",
-        "ajv-draft-04": "^1.0.0",
         "ajv-formats": "^2.1.1"
       },
       "bin": {
@@ -1477,19 +1476,6 @@
         "url": "https://github.com/sponsors/epoberezkin"
       }
     },
-    "node_modules/ajv-draft-04": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/ajv-draft-04/-/ajv-draft-04-1.0.0.tgz",
-      "integrity": "sha512-mv00Te6nmYbRp5DCwclxtt7yV/joXJPGS7nM+97GdxvuttCOfgI3K4U25zboyeX0O+myI8ERluxQe5wljMmVIw==",
-      "peerDependencies": {
-        "ajv": "^8.5.0"
-      },
-      "peerDependenciesMeta": {
-        "ajv": {
-          "optional": true
-        }
-      }
-    },
     "node_modules/ajv-formats": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/ajv-formats/-/ajv-formats-2.1.1.tgz",
@@ -1681,9 +1667,9 @@
       "license": "MIT"
     },
     "node_modules/brace-expansion": {
-      "version": "2.0.2",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-2.0.2.tgz",
-      "integrity": "sha512-Jt0vHyM+jmUBqojB7E1NIYadt0vI0Qxjxd2TErW94wDz+E2LAm5vKMXXwg6ZZBTHPuUlDgQHKXvjGBdfcF1ZDQ==",
+      "version": "2.1.1",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-2.1.1.tgz",
+      "integrity": "sha512-WR1cURNjuvBLMZBMbqM0UoE+WAfdUcEV1ccD8PVBVOI+Z3ND4+SZbN8RsfT2bMuG1qwz5RFvPukSZm5fF2D5eA==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
@@ -2192,9 +2178,9 @@
       "license": "MIT"
     },
     "node_modules/fast-uri": {
-      "version": "3.1.0",
-      "resolved": "https://registry.npmjs.org/fast-uri/-/fast-uri-3.1.0.tgz",
-      "integrity": "sha512-iPeeDKJSWf4IEOasVVrknXpaBV0IApz/gp7S2bb7Z4Lljbl2MGJRqInZiUrQwV16cpzw/D3S5j5Julj/gT52AA==",
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/fast-uri/-/fast-uri-3.1.2.tgz",
+      "integrity": "sha512-rVjf7ArG3LTk+FS6Yw81V1DLuZl1bRbNrev6Tmd/9RaroeeRRJhAt7jg/6YFxbvAQXUCavSoZhPPj6oOx+5KjQ==",
       "funding": [
         {
           "type": "github",
@@ -3105,9 +3091,9 @@
       }
     },
     "node_modules/jest-util/node_modules/picomatch": {
-      "version": "4.0.3",
-      "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-4.0.3.tgz",
-      "integrity": "sha512-5gTmgEY/sqK6gFXLIsQNH19lWb4ebPDLA4SdLP7dsWkIXHWlG66oPuVvXSGFPppYZz8ZDZq0dYYrbHfBCVUb1Q==",
+      "version": "4.0.4",
+      "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-4.0.4.tgz",
+      "integrity": "sha512-QP88BAKvMam/3NxH6vj2o21R6MjxZUAd6nlwAS/pnGvN9IVLocLHxGYIzFhg6fUQ+5th6P4dv4eW9jX3DSIj7A==",
       "dev": true,
       "license": "MIT",
       "engines": {
@@ -3632,9 +3618,9 @@
       "license": "ISC"
     },
     "node_modules/picomatch": {
-      "version": "2.3.1",
-      "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-2.3.1.tgz",
-      "integrity": "sha512-JU3teHTNjmE2VCGFzuY8EXzCDVwEqB2a8fsIvwaStHhAWJEeVd1o1QD80CU6+ZdEXXSLbSsuLwJjkCBWqRQUVA==",
+      "version": "2.3.2",
+      "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-2.3.2.tgz",
+      "integrity": "sha512-V7+vQEJ06Z+c5tSye8S+nHUfI51xoXIXjHQ99cQtKUkQqqO1kO/KCJUfZXuB47h/YBlDhah2H3hdUGXn8ie0oA==",
       "dev": true,
       "license": "MIT",
       "engines": {
@@ -4076,9 +4062,9 @@
       }
     },
     "node_modules/test-exclude/node_modules/brace-expansion": {
-      "version": "1.1.12",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.12.tgz",
-      "integrity": "sha512-9T9UjW3r0UW5c1Q7GTwllptXwhvYmEzFhzMfZ9H7FQWt+uZePjZPjBP/W1ZEyZ1twGWom5/56TF4lPcqjnDHcg==",
+      "version": "1.1.15",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.15.tgz",
+      "integrity": "sha512-EwOCDEex4quD37XhqM3omwtMoJjr//isUZz1JopUNWms+4Z2ViyM/k1YIRePpoVNnQhENnxtFjLaxNHrT7xIUg==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
diff --git a/package.json b/package.json
index 3afb6d5..13cd24c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@adobe/reactor-validator",
-  "version": "3.0.0",
+  "version": "3.1.0-beta.1",
   "description": "Validates a Tags extension package.",
   "main": "lib/index.js",
   "exports": {
@@ -26,7 +26,6 @@
   "dependencies": {
     "@adobe/reactor-turbine-schemas": "^10.8.0",
     "ajv": "^8.12.0",
-    "ajv-draft-04": "^1.0.0",
     "ajv-formats": "^2.1.1"
   },
   "engines": {
diff --git a/tests/draft4-compliance/draft4-compliance.test.js b/tests/draft4-compliance/draft4-compliance.test.js
new file mode 100644
index 0000000..32adf9d
--- /dev/null
+++ b/tests/draft4-compliance/draft4-compliance.test.js
@@ -0,0 +1,224 @@
+/***************************************************************************************
+ * (c) 2017 Adobe. All rights reserved.
+ * This file is licensed to you under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under
+ * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+ * OF ANY KIND, either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ ****************************************************************************************/
+
+// Verifies that the AJV v8 instance created by createDraft4Ajv correctly handles JSON Schema
+// draft-04 features. These tests exist specifically to guard against regressions if the
+// vocabulary setup in createDraft4Ajv.js is changed — the turbine platform schemas do not
+// exercise all draft-04 features, so integration tests alone are not sufficient.
+
+'use strict';
+var createDraft4Ajv = require('../../lib/createDraft4Ajv');
+
+describe('draft-04 AJV compliance', () => {
+  var ajv;
+
+  beforeEach(() => {
+    ajv = createDraft4Ajv();
+  });
+
+  // ─── Boolean exclusiveMinimum ─────────────────────────────────────────────────
+  // draft-04 uses { minimum: N, exclusiveMinimum: true } to mean "strictly greater than N".
+  // AJV v8's built-in limitNumber does not support this — it expects exclusiveMinimum to be
+  // a number (draft-07 style). limitNumberDraft4 in createDraft4Ajv.js handles this correctly.
+
+  describe('boolean exclusiveMinimum (draft-04 style)', () => {
+    it('rejects the boundary value when exclusiveMinimum is true', () => {
+      var schema = { type: 'number', minimum: 5, exclusiveMinimum: true };
+      expect(ajv.validate(schema, 5)).toBe(false);
+    });
+
+    it('accepts a value above the boundary', () => {
+      var schema = { type: 'number', minimum: 5, exclusiveMinimum: true };
+      expect(ajv.validate(schema, 6)).toBe(true);
+    });
+
+    it('accepts the boundary value when exclusiveMinimum is absent', () => {
+      var schema = { type: 'number', minimum: 5 };
+      expect(ajv.validate(schema, 5)).toBe(true);
+    });
+
+    it('accepts the boundary value when exclusiveMinimum is false', () => {
+      var schema = { type: 'number', minimum: 5, exclusiveMinimum: false };
+      expect(ajv.validate(schema, 5)).toBe(true);
+    });
+  });
+
+  // ─── Boolean exclusiveMaximum ─────────────────────────────────────────────────
+
+  describe('boolean exclusiveMaximum (draft-04 style)', () => {
+    it('rejects the boundary value when exclusiveMaximum is true', () => {
+      var schema = { type: 'number', maximum: 5, exclusiveMaximum: true };
+      expect(ajv.validate(schema, 5)).toBe(false);
+    });
+
+    it('accepts a value below the boundary', () => {
+      var schema = { type: 'number', maximum: 5, exclusiveMaximum: true };
+      expect(ajv.validate(schema, 4)).toBe(true);
+    });
+
+    it('accepts the boundary value when exclusiveMaximum is absent', () => {
+      var schema = { type: 'number', maximum: 5 };
+      expect(ajv.validate(schema, 5)).toBe(true);
+    });
+
+    it('accepts the boundary value when exclusiveMaximum is false', () => {
+      var schema = { type: 'number', maximum: 5, exclusiveMaximum: false };
+      expect(ajv.validate(schema, 5)).toBe(true);
+    });
+  });
+
+  // ─── Draft-04 meta-schema registration ───────────────────────────────────────
+  // The draft-04 meta-schema is registered so AJV validates that the turbine platform schemas
+  // are well-formed draft-04 at compile time. validateSchema() uses the registered meta-schema
+  // to check schema structure — it returns true for valid draft-04 and false for invalid.
+
+  describe('draft-04 meta-schema registration', () => {
+    it('recognizes { minimum, exclusiveMinimum: true } as a valid draft-04 schema', () => {
+      var schema = { type: 'number', minimum: 0, exclusiveMinimum: true };
+      expect(ajv.validateSchema(schema)).toBe(true);
+    });
+
+    it('rejects draft-07 style { exclusiveMinimum: 0 } as invalid draft-04', () => {
+      // In draft-04 exclusiveMinimum must be a boolean, not a number.
+      var schema = { exclusiveMinimum: 0 };
+      expect(ajv.validateSchema(schema)).toBe(false);
+    });
+
+    it('rejects exclusiveMinimum without a sibling minimum', () => {
+      // The draft-04 meta-schema declares a dependency: exclusiveMinimum requires minimum.
+      var schema = { type: 'number', exclusiveMinimum: true };
+      expect(ajv.validateSchema(schema)).toBe(false);
+    });
+
+    it('rejects exclusiveMaximum without a sibling maximum', () => {
+      var schema = { type: 'number', exclusiveMaximum: true };
+      expect(ajv.validateSchema(schema)).toBe(false);
+    });
+  });
+
+  // ─── $ref with definitions ────────────────────────────────────────────────────
+  // draft-04 uses "definitions" (not "$defs") for reusable sub-schemas.
+  // This is the primary pattern used by the turbine platform schemas.
+
+  describe('$ref with definitions', () => {
+    it('resolves $ref against definitions in the same schema', () => {
+      var schema = {
+        definitions: {
+          positiveNumber: { type: 'number', minimum: 1 }
+        },
+        type: 'object',
+        properties: {
+          count: { '$ref': '#/definitions/positiveNumber' }
+        },
+        required: ['count']
+      };
+      expect(ajv.validate(schema, { count: 5 })).toBe(true);
+      expect(ajv.validate(schema, { count: 0 })).toBe(false);
+      expect(ajv.validate(schema, {})).toBe(false);
+    });
+
+    it('resolves nested $ref chains through definitions', () => {
+      var schema = {
+        definitions: {
+          nonEmptyString: { type: 'string', minLength: 1 },
+          label: { '$ref': '#/definitions/nonEmptyString' }
+        },
+        type: 'object',
+        properties: {
+          name: { '$ref': '#/definitions/label' }
+        },
+        required: ['name']
+      };
+      expect(ajv.validate(schema, { name: 'hello' })).toBe(true);
+      expect(ajv.validate(schema, { name: '' })).toBe(false);
+    });
+  });
+
+  // ─── id keyword ───────────────────────────────────────────────────────────────
+  // draft-04 uses "id" (not "$id") for schema identification. schemaId: 'id' in the AJV
+  // options tells AJV to use "id" as the canonical schema identifier.
+
+  describe('id keyword', () => {
+    it('accepts a schema that uses id for identification', () => {
+      var schema = {
+        id: 'http://example.com/test-schema#',
+        type: 'object',
+        properties: {
+          name: { type: 'string' }
+        },
+        required: ['name']
+      };
+      expect(ajv.validate(schema, { name: 'hello' })).toBe(true);
+      expect(ajv.validate(schema, { name: 123 })).toBe(false);
+      expect(ajv.validate(schema, {})).toBe(false);
+    });
+  });
+
+  // ─── additionalItems ──────────────────────────────────────────────────────────
+  // Controls whether array items beyond those defined in "items" (as a tuple) are allowed.
+
+  describe('additionalItems', () => {
+    it('rejects extra array items when additionalItems is false', () => {
+      var schema = {
+        type: 'array',
+        items: [{ type: 'string' }, { type: 'number' }],
+        additionalItems: false
+      };
+      expect(ajv.validate(schema, ['hello', 42])).toBe(true);
+      expect(ajv.validate(schema, ['hello', 42, 'extra'])).toBe(false);
+    });
+
+    it('allows extra items when additionalItems is a schema and they match', () => {
+      var schema = {
+        type: 'array',
+        items: [{ type: 'string' }],
+        additionalItems: { type: 'number' }
+      };
+      expect(ajv.validate(schema, ['hello', 1, 2, 3])).toBe(true);
+      expect(ajv.validate(schema, ['hello', 'not-a-number'])).toBe(false);
+    });
+  });
+
+  // ─── dependencies ─────────────────────────────────────────────────────────────
+  // draft-04 "dependencies" declares that the presence of one property requires
+  // either another property (property dependency) or a sub-schema to validate (schema dependency).
+
+  describe('dependencies', () => {
+    it('requires a dependent property when its dependency is present', () => {
+      var schema = {
+        type: 'object',
+        dependencies: {
+          creditCard: ['billingAddress']
+        }
+      };
+      expect(ajv.validate(schema, { creditCard: '1234', billingAddress: '123 Main St' })).toBe(true);
+      expect(ajv.validate(schema, { creditCard: '1234' })).toBe(false);
+      expect(ajv.validate(schema, { billingAddress: '123 Main St' })).toBe(true);
+      expect(ajv.validate(schema, {})).toBe(true);
+    });
+
+    it('validates a schema dependency when the trigger property is present', () => {
+      var schema = {
+        type: 'object',
+        dependencies: {
+          name: {
+            properties: { name: { type: 'string', minLength: 1 } },
+            required: ['name']
+          }
+        }
+      };
+      expect(ajv.validate(schema, { name: 'Alice' })).toBe(true);
+      expect(ajv.validate(schema, { name: '' })).toBe(false);
+      expect(ajv.validate(schema, {})).toBe(true);
+    });
+  });
+});