fix(133,137): correct Create/Apply HTTP response codes to 201

Create should return 201 Created, not 200 OK, per RFC 7231. Apply should
return 201 when creating and 200 when updating. The aep-2026 release
incorrectly specified 200 for both; this corrects that with should-level
guidance to allow backwards compatibility.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: thegagne

aep/general/0133/aep.md.j2

@@ -90,7 +90,14 @@ Create methods implement a common request message pattern:
 
 {% tab oas %}
 
-{% sample '../example.oas.yaml', '$.paths./publishers/{publisher_id}/books.post.responses.200' %}
+{% sample '../example.oas.yaml', '$.paths./publishers/{publisher_id}/books.post.responses.201' %}
+
+- The response **should** return a `201 Created` HTTP status code.
+
+**Note:** The aep-2026 release incorrectly specified `200 OK` for Create
+responses. This guidance corrects that: `201 Created` is the appropriate status
+code per [RFC 7231][rfc-7231]. Implementations **should** accept `200` for
+backwards compatibility.
 
 - The response **must** be the resource itself. There is no separate response
   schema.
@@ -195,6 +202,7 @@ the ID of the newly-created resource.
 Having a user-specified ID also means the client can precalculate the resource
 path and use it in references from other resources.
 
+[rfc-7231]: https://datatracker.ietf.org/doc/html/rfc7231#section-4.3.3
 [data plane]: ./0111.md#data-plane
 [errors]: ./0193
 [field_behavior]: ./0203

aep/general/0137/aep.md.j2

@@ -108,10 +108,15 @@ Apply methods implement a common request message pattern:
 
 {% tab oas %}
 
-{% sample '../example.oas.yaml', '$.paths./publishers/{publisher_id}/books/{book_id}.put.responses.200' %}
+{% sample '../example.oas.yaml', '$.paths./publishers/{publisher_id}/books/{book_id}.put.responses' %}
 
-- If the resource is created, the response **must** return a `201` status code.
-- If the resource is updated, the response **must** return a `200` status code.
+- If the resource is created, the response **should** return a `201` status code.
+- If the resource is updated, the response **should** return a `200` status code.
+
+**Note:** The aep-2026 release incorrectly specified `200 OK` for both cases.
+This guidance corrects that: `201 Created` is the appropriate status code when
+a resource is created, per [RFC 7231][rfc-7231]. Implementations **should**
+accept `200` for backwards compatibility.
 
 {% endtabs %}
 
@@ -159,4 +164,5 @@ See [AEP-134's patch and put](/134#patch-and-put) for more information.
 - For ensuring idempotency in `Apply` methods, see [idempotency](/idempotency).
 - For naming resources involving Unicode, see [unicode](/unicode).
 
+[rfc-7231]: https://datatracker.ietf.org/doc/html/rfc7231#section-4.3.3
 [strong consistency]: ./0121.md#strong-consistency

aep/general/example.oas.yaml

@@ -196,7 +196,7 @@ paths:
               $ref: '#/components/schemas/isbn'
         required: true
       responses:
-        '200':
+        '201':
           content:
             application/json:
               schema:
@@ -269,7 +269,7 @@ paths:
               $ref: '#/components/schemas/publisher'
         required: true
       responses:
-        '200':
+        '201':
           content:
             application/json:
               schema:
@@ -354,7 +354,13 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/publisher'
-          description: Successful response
+          description: Successful response (updated)
+        '201':
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/publisher'
+          description: Successful response (created)
   /publishers/{publisher_id}/books:
     get:
       description: List method for book
@@ -411,7 +417,7 @@ paths:
               $ref: '#/components/schemas/book'
         required: true
       responses:
-        '200':
+        '201':
           content:
             application/json:
               schema:
@@ -516,7 +522,13 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/book'
-          description: Successful response
+          description: Successful response (updated)
+        '201':
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/book'
+          description: Successful response (created)
   /publishers/{publisher_id}/books/{book_id}/editions:
     get:
       description: List method for book-edition
@@ -579,7 +591,7 @@ paths:
               $ref: '#/components/schemas/book-edition'
         required: true
       responses:
-        '200':
+        '201':
           content:
             application/json:
               schema: