diff --git a/CHANGELOG.md b/CHANGELOG.md
index 33921bf4..08782ae7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -84,6 +84,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Added `AwarenessAttributeStats` to `/_cluster/health` ([#534](https://github.com/opensearch-project/opensearch-api-specification/pull/534))
 - Added `cache_reserved_in_bytes` to `ClusterFileSystem` ([#534](https://github.com/opensearch-project/opensearch-api-specification/pull/534))
 - Added `cluster_manager` to `ClusterNodeCount` ([#534](https://github.com/opensearch-project/opensearch-api-specification/pull/534))
+- Added request and response schemas for `/_cluster/routing/awareness/{attribute}/weights` ([#524](https://github.com/opensearch-project/opensearch-api-specification/pull/524))
 
 ### Changed
 
diff --git a/TESTING_GUIDE.md b/TESTING_GUIDE.md
index 98dae41a..6c38c31f 100644
--- a/TESTING_GUIDE.md
+++ b/TESTING_GUIDE.md
@@ -201,6 +201,8 @@ Consider the following chapters in [ml/model_groups](tests/plugins/ml/ml/model_g
 ```
 As you can see, the `output` field in the first chapter saves the `model_group_id` from the response body. This value is then used in the subsequent chapters to query and delete the model group.
 
+You can also supply defaults in both output and input values, e.g. `version: payload.version ? 0` or `${weights._version ? 0}` used in [cluster/routing/awareness/weights.yaml](tests/default/cluster/routing/awareness/weights.yaml).
+
 You can also reuse output in payload expectations. See [tests/plugins/index_state_management/nodes/plugins/index_state_management.yaml](tests/plugins/index_state_management/nodes/plugins/index_state_management.yaml) for an example.
 
 ### Managing Versions
diff --git a/spec/namespaces/cluster.yaml b/spec/namespaces/cluster.yaml
index d526738d..12435950 100644
--- a/spec/namespaces/cluster.yaml
+++ b/spec/namespaces/cluster.yaml
@@ -195,6 +195,8 @@ paths:
         url: https://opensearch.org/docs/latest/api-reference/cluster-api/cluster-awareness/#example-weighted-round-robin-search
       parameters:
         - $ref: '#/components/parameters/cluster.put_weighted_routing::path.attribute'
+      requestBody:
+        $ref: '#/components/requestBodies/cluster.put_weighted_routing'
       responses:
         '200':
           $ref: '#/components/responses/cluster.put_weighted_routing@200'
@@ -465,6 +467,11 @@ paths:
           $ref: '#/components/responses/cluster.remote_info@200'
 components:
   requestBodies:
+    cluster.put_weighted_routing:
+      content:
+        application/json:
+          schema:
+            $ref: '../schemas/cluster.weighted_routing.yaml#/components/schemas/Weights'
     cluster.allocation_explain:
       content:
         application/json:
@@ -647,7 +654,11 @@ components:
             required:
               - persistent
               - transient
-    cluster.get_weighted_routing@200: {}
+    cluster.get_weighted_routing@200:
+      content:
+        application/json:
+          schema:
+            $ref: '../schemas/cluster.weighted_routing.yaml#/components/schemas/WeightsResponse'
     cluster.health@200:
       content:
         application/json:
@@ -692,7 +703,11 @@ components:
               - acknowledged
               - persistent
               - transient
-    cluster.put_weighted_routing@200: {}
+    cluster.put_weighted_routing@200:
+      content:
+        application/json:
+          schema:
+            type: object
     cluster.remote_info@200:
       content:
         application/json:
diff --git a/spec/schemas/cluster.weighted_routing.yaml b/spec/schemas/cluster.weighted_routing.yaml
new file mode 100644
index 00000000..c4579ba8
--- /dev/null
+++ b/spec/schemas/cluster.weighted_routing.yaml
@@ -0,0 +1,23 @@
+openapi: 3.1.0
+info:
+  title: Schemas of Weighted Routing Category
+  description: Schemas of weighted routing category.
+  version: 1.0.0
+paths: {}
+components:
+  schemas:
+    Weights:
+      type: object
+      properties:
+        _version:
+          $ref: '_common.yaml#/components/schemas/VersionNumber'
+        weights:
+          type: object
+    WeightsResponse:
+      allOf:
+        - $ref: '#/components/schemas/Weights'
+        - type: object
+          properties:
+            discovered_cluster_manager:
+              type: boolean
+      
diff --git a/tests/default/cluster/routing/awareness/weights.yaml b/tests/default/cluster/routing/awareness/weights.yaml
new file mode 100644
index 00000000..78837314
--- /dev/null
+++ b/tests/default/cluster/routing/awareness/weights.yaml
@@ -0,0 +1,36 @@
+$schema: ../../../../../json_schemas/test_story.schema.yaml
+
+description: Test cluster routing settings.
+version: '>= 2.16'
+prologues:
+  - path: /_cluster/settings
+    method: PUT
+    request:
+      payload:
+        transient:
+          cluster.routing.allocation.awareness.attributes: zone
+          cluster.routing.allocation.awareness.force.zone.values:
+            - zone-a
+            - zone-b
+chapters:
+  - synopsis: Get zone routing weights.
+    id: weights
+    path: /_cluster/routing/awareness/{attribute}/weights
+    method: GET
+    parameters:
+      attribute: zone
+    output:
+      version: payload._version ? -1
+  - synopsis: Update zone routing weights.
+    path: /_cluster/routing/awareness/{attribute}/weights
+    method: PUT
+    parameters:
+      attribute: zone
+    request:
+      payload:
+        weights:
+          zone-a: '1'
+          zone-b: '0'
+        _version: ${weights.version}
+    response:
+      status: 200
diff --git a/tools/src/tester/ChapterOutput.ts b/tools/src/tester/ChapterOutput.ts
index d8fd6d11..e3c9ae85 100644
--- a/tools/src/tester/ChapterOutput.ts
+++ b/tools/src/tester/ChapterOutput.ts
@@ -35,7 +35,11 @@ export class ChapterOutput {
         if (response.payload === undefined) {
           return { evaluation: { result: Result.ERROR, message: 'No payload found in response, but expected output: ' + path } }
         }
-        value = _.get(response, path)
+        const rhs = path.replaceAll(' ', '').split('?', 2)
+        let default_value: any = parseFloat(rhs[1])
+        if (Number.isNaN(default_value)) default_value = rhs[1]
+        value = _.get(response, rhs[0])
+        if (value === undefined) value = default_value
         if (value === undefined) {
           return { evaluation: { result: Result.ERROR, message: `Expected to find non undefined value at \`${path}\`.` } }
         }
diff --git a/tools/src/tester/StoryOutputs.ts b/tools/src/tester/StoryOutputs.ts
index 41b8d9e7..08171e45 100644
--- a/tools/src/tester/StoryOutputs.ts
+++ b/tools/src/tester/StoryOutputs.ts
@@ -50,7 +50,7 @@ export class StoryOutputs {
   resolve_string (str: string): any {
     const ref = OutputReference.parse(str)
     if (ref) {
-      return this.get_output_value(ref.chapter_id, ref.output_name)
+      return this.get_output_value(ref.chapter_id, ref.output_name) ?? ref.default_value
     } else {
       return str
     }
diff --git a/tools/src/tester/types/eval.types.ts b/tools/src/tester/types/eval.types.ts
index eacb2c62..9474836c 100644
--- a/tools/src/tester/types/eval.types.ts
+++ b/tools/src/tester/types/eval.types.ts
@@ -87,15 +87,20 @@ export enum Result {
 export class OutputReference {
   chapter_id: string
   output_name: string
-  private constructor (chapter_id: string, output_name: string) {
+  default_value?: string
+  private constructor (chapter_id: string, output_name: string, default_value?: string) {
     this.chapter_id = chapter_id
     this.output_name = output_name
+    this.default_value = default_value
   }
 
   static parse (str: string): OutputReference | undefined {
     if (str.startsWith('${') && str.endsWith('}')) {
-      const spl = str.slice(2, -1).split('.', 2)
-      return { chapter_id: spl[0], output_name: spl[1] }
+      const spl = str.slice(2, -1).replaceAll(' ', '').split('.', 2)
+      const rhs = spl[1].split('?', 2)
+      let default_value: any = parseFloat(rhs[1])
+      if (Number.isNaN(default_value)) default_value = rhs[1]
+      return { chapter_id: spl[0], output_name: rhs[0], default_value }
     }
     return undefined
   }
diff --git a/tools/tests/tester/ChapterOutput.test.ts b/tools/tests/tester/ChapterOutput.test.ts
index f5ace6ed..06be1bea 100644
--- a/tools/tests/tester/ChapterOutput.test.ts
+++ b/tools/tests/tester/ChapterOutput.test.ts
@@ -36,7 +36,8 @@ describe('with an object response', () => {
         { d: 2 },
         { e: 3 }
       ]
-    }
+    },
+    zero: 0
   })
 
   test('returns nested values', () => {
@@ -68,6 +69,18 @@ describe('with an object response', () => {
     })
   })
 
+  test('uses a default value', () => {
+    expect(ChapterOutput.extract_output_values(response, { x: 'payload.a.b.x[0] ? -1' })).toEqual(
+      passed_output({ x: -1 })
+    )
+  })
+
+  test('does not use a default value on a numeric zero', () => {
+    expect(ChapterOutput.extract_output_values(response, { x: 'payload.zero ? -1' })).toEqual(
+      passed_output({ x: 0 })
+    )
+  })
+
   test('errors on invalid source', () => {
     expect(ChapterOutput.extract_output_values(response, { x: 'foobar' })).toEqual({
       evaluation: {
diff --git a/tools/tests/tester/StoryOutputs.test.ts b/tools/tests/tester/StoryOutputs.test.ts
index 3017b7a6..450ddfd3 100644
--- a/tools/tests/tester/StoryOutputs.test.ts
+++ b/tools/tests/tester/StoryOutputs.test.ts
@@ -13,13 +13,18 @@ import { StoryOutputs } from 'tester/StoryOutputs'
 const story_outputs = new StoryOutputs({
   chapter_id: new ChapterOutput({
     x: 1,
-    y: 2
+    y: 2,
+    n: null,
+    z: 0
   })
 })
 
 test('resolve_string', () => {
   expect(story_outputs.resolve_string('${chapter_id.x}')).toEqual(1)
   expect(story_outputs.resolve_string('${invalid_id.x}')).toBeUndefined()
+  expect(story_outputs.resolve_string('${chapter_id.n ? x}')).toEqual('x')
+  expect(story_outputs.resolve_string('${chapter_id.n ? 0}')).toEqual(0)
+  expect(story_outputs.resolve_string('${chapter_id.z ? -1}')).toEqual(0)
   expect(story_outputs.resolve_string('some_str')).toEqual('some_str')
 })