diff --git a/packages/catalog-model/examples/ai-resources/use-internal-apis-rule.yaml b/packages/catalog-model/examples/ai-resources/use-internal-apis-rule.yaml
index bd06d5bb22..06e08bc959 100644
--- a/packages/catalog-model/examples/ai-resources/use-internal-apis-rule.yaml
+++ b/packages/catalog-model/examples/ai-resources/use-internal-apis-rule.yaml
@@ -8,3 +8,8 @@ spec:
   lifecycle: production
   owner: team-a
   system: artist-engagement-portal
+  disciplines:
+    - web
+    - backend
+  category: architecture
+  rationale: Ensures consistent error handling, authentication, and observability across all service calls
diff --git a/packages/catalog-model/report-alpha.api.md b/packages/catalog-model/report-alpha.api.md
index 550a79c45c..dfd6882004 100644
--- a/packages/catalog-model/report-alpha.api.md
+++ b/packages/catalog-model/report-alpha.api.md
@@ -14,7 +14,8 @@ export const aiResourceEntityModel: CatalogModelLayer;
 // @alpha
 export type AiResourceEntityV1alpha1 =
   | AiResourceEntityV1alpha1Default
-  | SkillAiResourceEntityV1alpha1;
+  | SkillAiResourceEntityV1alpha1
+  | RuleAiResourceEntityV1alpha1;
 
 // @alpha
 export interface AiResourceEntityV1alpha1Default extends Entity {
@@ -484,6 +485,11 @@ export const isAiResourceEntity: (
   entity: Entity,
 ) => entity is AiResourceEntityV1alpha1;
 
+// @alpha
+export const isRuleAiResourceEntity: (
+  entity: Entity,
+) => entity is RuleAiResourceEntityV1alpha1;
+
 // @alpha
 export const isSkillAiResourceEntity: (
   entity: Entity,
@@ -494,6 +500,27 @@ export type KindValidator = {
   check(entity: Entity): Promise<boolean>;
 };
 
+// @alpha
+export interface RuleAiResourceEntityV1alpha1 extends Entity {
+  // (undocumented)
+  apiVersion: 'backstage.io/v1alpha1';
+  // (undocumented)
+  kind: 'AiResource';
+  // (undocumented)
+  spec: {
+    type: 'rule';
+    lifecycle: string;
+    owner: string;
+    system?: string;
+    disciplines?: string[];
+    category: string;
+    rationale: string;
+  };
+}
+
+// @alpha
+export const ruleAiResourceEntityV1alpha1Validator: KindValidator;
+
 // @alpha
 export interface SkillAiResourceEntityV1alpha1 extends Entity {
   // (undocumented)
diff --git a/packages/catalog-model/src/alpha.ts b/packages/catalog-model/src/alpha.ts
index d7c7399865..219513f167 100644
--- a/packages/catalog-model/src/alpha.ts
+++ b/packages/catalog-model/src/alpha.ts
@@ -31,12 +31,15 @@ export type {
   AiResourceEntityV1alpha1,
   AiResourceEntityV1alpha1Default,
   SkillAiResourceEntityV1alpha1,
+  RuleAiResourceEntityV1alpha1,
 } from './kinds/AiResourceEntityV1alpha1';
 export {
   aiResourceEntityV1alpha1Validator,
   skillAiResourceEntityV1alpha1Validator,
+  ruleAiResourceEntityV1alpha1Validator,
   isAiResourceEntity,
   isSkillAiResourceEntity,
+  isRuleAiResourceEntity,
   aiResourceEntityModel,
 } from './kinds/AiResourceEntityV1alpha1';
 export * from './model';
diff --git a/packages/catalog-model/src/kinds/AiResourceEntityV1alpha1.test.ts b/packages/catalog-model/src/kinds/AiResourceEntityV1alpha1.test.ts
index aa75b414c5..e3fa82754a 100644
--- a/packages/catalog-model/src/kinds/AiResourceEntityV1alpha1.test.ts
+++ b/packages/catalog-model/src/kinds/AiResourceEntityV1alpha1.test.ts
@@ -18,10 +18,13 @@ import type { Entity } from '../entity/Entity';
 import {
   type AiResourceEntityV1alpha1Default,
   type SkillAiResourceEntityV1alpha1,
+  type RuleAiResourceEntityV1alpha1,
   aiResourceEntityV1alpha1Validator as defaultValidator,
   skillAiResourceEntityV1alpha1Validator as skillValidator,
+  ruleAiResourceEntityV1alpha1Validator as ruleValidator,
   isAiResourceEntity,
   isSkillAiResourceEntity,
+  isRuleAiResourceEntity,
 } from './AiResourceEntityV1alpha1';
 
 describe('AiResourceV1alpha1 default validator', () => {
@@ -199,6 +202,101 @@ describe('AiResourceV1alpha1 skill validator', () => {
   });
 });
 
+describe('AiResourceV1alpha1 rule validator', () => {
+  let entity: RuleAiResourceEntityV1alpha1;
+
+  beforeEach(() => {
+    entity = {
+      apiVersion: 'backstage.io/v1alpha1',
+      kind: 'AiResource',
+      metadata: {
+        name: 'use-internal-apis',
+      },
+      spec: {
+        type: 'rule',
+        lifecycle: 'production',
+        owner: 'frontend-platform',
+        disciplines: ['web', 'backend'],
+        category: 'architecture',
+        rationale: 'Ensures consistent error handling across all service calls',
+      },
+    };
+  });
+
+  it('accepts valid rule data with all fields', async () => {
+    await expect(ruleValidator.check(entity)).resolves.toBe(true);
+  });
+
+  it('accepts rule with only required fields', async () => {
+    entity.spec = {
+      type: 'rule',
+      lifecycle: 'production',
+      owner: 'team-a',
+      category: 'security',
+      rationale: 'Prevents credential leaks',
+    };
+    await expect(ruleValidator.check(entity)).resolves.toBe(true);
+  });
+
+  it('rejects non-rule type', async () => {
+    (entity as any).spec.type = 'skill';
+    await expect(ruleValidator.check(entity)).rejects.toThrow(/type/);
+  });
+
+  it('rejects missing category', async () => {
+    delete (entity as any).spec.category;
+    await expect(ruleValidator.check(entity)).rejects.toThrow(/category/);
+  });
+
+  it('rejects empty category', async () => {
+    (entity as any).spec.category = '';
+    await expect(ruleValidator.check(entity)).rejects.toThrow(/category/);
+  });
+
+  it('rejects missing rationale', async () => {
+    delete (entity as any).spec.rationale;
+    await expect(ruleValidator.check(entity)).rejects.toThrow(/rationale/);
+  });
+
+  it('rejects empty rationale', async () => {
+    (entity as any).spec.rationale = '';
+    await expect(ruleValidator.check(entity)).rejects.toThrow(/rationale/);
+  });
+
+  it('accepts missing optional fields', async () => {
+    delete (entity as any).spec.system;
+    delete (entity as any).spec.disciplines;
+    await expect(ruleValidator.check(entity)).resolves.toBe(true);
+  });
+
+  it('rejects disciplines with empty strings', async () => {
+    (entity as any).spec.disciplines = [''];
+    await expect(ruleValidator.check(entity)).rejects.toThrow(/disciplines/);
+  });
+});
+
+describe('isRuleAiResourceEntity', () => {
+  it('returns true for a rule AiResource', () => {
+    const entity: Entity = {
+      apiVersion: 'backstage.io/v1alpha1',
+      kind: 'AiResource',
+      metadata: { name: 'test' },
+      spec: { type: 'rule' },
+    };
+    expect(isRuleAiResourceEntity(entity)).toBe(true);
+  });
+
+  it('returns false for a non-rule AiResource', () => {
+    const entity: Entity = {
+      apiVersion: 'backstage.io/v1alpha1',
+      kind: 'AiResource',
+      metadata: { name: 'test' },
+      spec: { type: 'skill' },
+    };
+    expect(isRuleAiResourceEntity(entity)).toBe(false);
+  });
+});
+
 describe('isAiResourceEntity', () => {
   it('returns true when apiVersion and kind match', () => {
     const entity: Entity = {
diff --git a/packages/catalog-model/src/kinds/AiResourceEntityV1alpha1.ts b/packages/catalog-model/src/kinds/AiResourceEntityV1alpha1.ts
index 53fa20d17a..1655e0fdbc 100644
--- a/packages/catalog-model/src/kinds/AiResourceEntityV1alpha1.ts
+++ b/packages/catalog-model/src/kinds/AiResourceEntityV1alpha1.ts
@@ -21,6 +21,7 @@ import type { KindValidator } from './types';
 import type { JsonObject } from '@backstage/types';
 import defaultJsonSchema from '../schema/kinds/AiResource.v1alpha1.schema.json';
 import skillJsonSchema from '../schema/kinds/AiResource.v1alpha1.skill.schema.json';
+import ruleJsonSchema from '../schema/kinds/AiResource.v1alpha1.rule.schema.json';
 
 /**
  * Default AiResource entity for types that don't have a structured spec.
@@ -59,6 +60,26 @@ export interface SkillAiResourceEntityV1alpha1 extends Entity {
   };
 }
 
+/**
+ * AiResource entity with spec.type 'rule'. Represents a governance rule
+ * or constraint for AI coding tools.
+ *
+ * @alpha
+ */
+export interface RuleAiResourceEntityV1alpha1 extends Entity {
+  apiVersion: 'backstage.io/v1alpha1';
+  kind: 'AiResource';
+  spec: {
+    type: 'rule';
+    lifecycle: string;
+    owner: string;
+    system?: string;
+    disciplines?: string[];
+    category: string;
+    rationale: string;
+  };
+}
+
 /**
  * Backstage catalog AiResource kind Entity. Represents contextual information
  * consumed by AI coding tools, such as skills and rules.
@@ -67,7 +88,8 @@ export interface SkillAiResourceEntityV1alpha1 extends Entity {
  */
 export type AiResourceEntityV1alpha1 =
   | AiResourceEntityV1alpha1Default
-  | SkillAiResourceEntityV1alpha1;
+  | SkillAiResourceEntityV1alpha1
+  | RuleAiResourceEntityV1alpha1;
 
 const defaultValidator = entityKindSchemaValidator(defaultJsonSchema);
 
@@ -115,6 +137,29 @@ export const isSkillAiResourceEntity = (
 ): entity is SkillAiResourceEntityV1alpha1 =>
   isAiResourceEntity(entity) && entity.spec?.type === 'skill';
 
+const ruleValidator = entityKindSchemaValidator(ruleJsonSchema);
+
+/**
+ * Entity data validator for {@link RuleAiResourceEntityV1alpha1}.
+ *
+ * @alpha
+ */
+export const ruleAiResourceEntityV1alpha1Validator: KindValidator = {
+  async check(data: Entity) {
+    return ruleValidator(data) === data;
+  },
+};
+
+/**
+ * Type guard for {@link RuleAiResourceEntityV1alpha1}.
+ *
+ * @alpha
+ */
+export const isRuleAiResourceEntity = (
+  entity: Entity,
+): entity is RuleAiResourceEntityV1alpha1 =>
+  isAiResourceEntity(entity) && entity.spec?.type === 'rule';
+
 const baseRelationFields = [
   {
     selector: { path: 'spec.owner' },
@@ -172,6 +217,14 @@ export const aiResourceEntityModel = createCatalogModelLayer({
             jsonSchema: skillJsonSchema as JsonObject,
           },
         },
+        {
+          name: 'v1alpha1',
+          specType: 'rule',
+          relationFields: baseRelationFields,
+          schema: {
+            jsonSchema: ruleJsonSchema as JsonObject,
+          },
+        },
       ],
     });
   },
diff --git a/packages/catalog-model/src/schema/kinds/AiResource.v1alpha1.rule.schema.json b/packages/catalog-model/src/schema/kinds/AiResource.v1alpha1.rule.schema.json
new file mode 100644
index 0000000000..48c0f3ee1e
--- /dev/null
+++ b/packages/catalog-model/src/schema/kinds/AiResource.v1alpha1.rule.schema.json
@@ -0,0 +1,87 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema",
+  "$id": "AiResourceV1alpha1Rule",
+  "description": "An AI resource of type 'rule', representing a governance rule or constraint for AI coding tools.",
+  "examples": [
+    {
+      "apiVersion": "backstage.io/v1alpha1",
+      "kind": "AiResource",
+      "metadata": {
+        "name": "use-internal-apis",
+        "description": "Agents must use internal API clients instead of raw HTTP calls"
+      },
+      "spec": {
+        "type": "rule",
+        "lifecycle": "production",
+        "owner": "frontend-platform",
+        "disciplines": ["web", "backend"],
+        "category": "architecture",
+        "rationale": "Ensures consistent error handling, authentication, and observability across all service calls"
+      }
+    }
+  ],
+  "allOf": [
+    {
+      "$ref": "Entity"
+    },
+    {
+      "type": "object",
+      "required": ["spec"],
+      "properties": {
+        "apiVersion": {
+          "enum": ["backstage.io/v1alpha1"]
+        },
+        "kind": {
+          "enum": ["AiResource"]
+        },
+        "spec": {
+          "type": "object",
+          "required": ["type", "lifecycle", "owner", "category", "rationale"],
+          "properties": {
+            "type": {
+              "type": "string",
+              "enum": ["rule"],
+              "description": "The type of AI resource."
+            },
+            "lifecycle": {
+              "type": "string",
+              "description": "The lifecycle state of the AI resource.",
+              "examples": ["experimental", "production", "deprecated"],
+              "minLength": 1
+            },
+            "owner": {
+              "type": "string",
+              "description": "An entity reference to the owner of the AI resource.",
+              "examples": ["frontend-platform", "user:john.johnson"],
+              "minLength": 1
+            },
+            "system": {
+              "type": "string",
+              "description": "An entity reference to the system that the AI resource belongs to.",
+              "minLength": 1
+            },
+            "disciplines": {
+              "type": "array",
+              "description": "Engineering disciplines this rule applies to.",
+              "items": {
+                "type": "string",
+                "minLength": 1
+              }
+            },
+            "category": {
+              "type": "string",
+              "description": "The category of this rule.",
+              "examples": ["security", "architecture", "style"],
+              "minLength": 1
+            },
+            "rationale": {
+              "type": "string",
+              "description": "Explanation of why this rule exists.",
+              "minLength": 1
+            }
+          }
+        }
+      }
+    }
+  ]
+}