diff --git a/typing-server/openapi.yaml b/typing-server/openapi.yaml
new file mode 100644
index 0000000..94e9455
--- /dev/null
+++ b/typing-server/openapi.yaml
@@ -0,0 +1,203 @@
+openapi: 3.0.0
+info:
+  title: Typing API
+  version: 1.0.0
+servers:
+  - url: http://localhost:8080
+    description: ローカル開発環境
+  - url: https://typemaster.com
+    description: 本番環境
+paths:
+  /users:
+    post:
+      summary: 新しいユーザーを作成
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                MailAdress:
+                  type: string
+                  maxLength: 255
+                HandleName:
+                  type: string
+                  maxLength: 36
+                Name:
+                  type: string
+                  maxLength: 36
+                HashedPassword:
+                  type: string
+                  maxLength: 255
+                Department:
+                  type: string
+                  enum: [CS, BI, IA]
+      responses:
+        '201':
+          description: ユーザー作成成功
+        '400':
+          description: 不正なリクエスト
+  /users/{userId}:
+    get:
+      summary: ユーザー情報を取得
+      parameters:
+        - in: path
+          name: userId
+          required: true
+          schema:
+            type: string
+      responses:
+        '200':
+          description: ユーザー情報取得成功
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/User'
+        '404':
+          description: ユーザーが見つからない
+  /users/{userId}/scores:
+    post:
+      summary: ユーザーのスコアを登録
+      parameters:
+        - in: path
+          name: userId
+          required: true
+          schema:
+            type: string
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                keystrokes:
+                  type: integer
+                accuracy:
+                  type: number
+                  format: float
+                score:
+                  type: number
+                  format: float
+                startedAt:
+                  type: string
+                  format: date-time
+                endedAt:
+                  type: string
+                  format: date-time
+      responses:
+        '201':
+          description: スコア登録成功
+        '400':
+          description: 不正なリクエスト
+  /users/{userId}/scores/{scoreId}:
+    get:
+      summary: 特定のスコア情報の取得
+      parameters:
+        - in: path
+          name: userId
+          required: true
+          schema:
+            type: string
+        - in: path
+          name: scoreId
+          required: true
+          schema:
+            type: string
+      responses:
+        '200':
+          description: スコア情報の取得成功
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Score'
+        '404':
+          description: スコアが見つからない
+
+    put:
+      summary: ユーザーのスコアを更新
+      parameters:
+        - in: path
+          name: userId
+          required: true
+          schema:
+            type: string
+        - in: path
+          name: scoreId
+          required: true
+          schema:
+            type: string
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                keystrokes:
+                  type: integer
+                accuracy:
+                  type: number
+                  format: float
+                score:
+                  type: number
+                  format: float
+                startedAt:
+                  type: string
+                  format: date-time
+                endedAt:
+                  type: string
+                  format: date-time
+      responses:
+        '200':
+          description: スコアの更新成功
+        '400':
+          description: 不正なリクエスト
+        '404':
+          description: スコアが見つからない
+components:
+  schemas:
+    User:
+      type: object
+      properties:
+        id:
+          type: string
+          format: uuid
+        MailAdress:
+          type: string
+        HandleName:
+          type: string
+        Name:
+          type: string
+        HashedPassword:
+          type: string
+        Department:
+          type: string
+          enum: [CS, BI, IA]
+        created_at:
+          type: string
+          format: date-time
+        updated_at:
+          type: string
+          format: date-time
+    Score:
+      type: object
+      properties:
+        id:
+          type: string
+          format: uuid
+        keystrokes:
+          type: integer
+        accuracy:
+          type: number
+          format: float
+        score:
+          type: number
+          format: float
+        startedAt:
+          type: string
+          format: date-time
+        endedAt:
+          type: string
+          format: date-time