Fix the response format of the `/send` endpoint

Fixes https://github.com/matrix-org/matrix-doc/issues/2236

api/server-server/transactions.yaml

@@ -77,43 +77,33 @@ paths:
             The result of processing the transaction. The server is to use this response even in
             the event of one or more PDUs failing to be processed.
           schema:
-            type: array
-            minItems: 2
-            maxItems: 2
-            items:
-              - type: integer
-                description: The value ``200``.
-                example: 200
-              - type: object
-                title: PDU Processing Results
-                description: The results for the processing of each PDU in the transaction.
-                properties:
-                  pdus:
-                    type: object
-                    description: |-
-                      The PDUs from the original transaction. The string key represents the ID of the
-                      PDU (event) that was processed.
-                    additionalProperties:
-                      type: object
-                      title: PDU Processing Result
-                      description: Information about how the PDU was handled.
-                      properties:
-                        error:
-                          type: string
-                          description: |-
-                            A human readable description about what went wrong in processing this PDU.
-                            If no error is present, the PDU can be considered successfully handled.
-                          example: "You are not allowed to send a message to this room."
-                required: ['pdus']
+            type: object
+            title: PDU Processing Results
+            description: The results for the processing of each PDU in the transaction.
+            properties:
+              pdus:
+                type: object
+                description: |-
+                  The PDUs from the original transaction. The string key represents the ID of the
+                  PDU (event) that was processed.
+                additionalProperties:
+                  type: object
+                  title: PDU Processing Result
+                  description: Information about how the PDU was handled.
+                  properties:
+                    error:
+                      type: string
+                      description: |-
+                        A human readable description about what went wrong in processing this PDU.
+                        If no error is present, the PDU can be considered successfully handled.
+                      example: "You are not allowed to send a message to this room."
+            required: ['pdus']
           examples:
-            application/json: [
-              200,
-              {
-                "pdus": {
-                  "$successful_event:example.org": {},
-                  "$failed_event:example.org": {
-                    "error": "You are not allowed to send a message to this room."
-                  }
+            application/json: {
+              "pdus": {
+                "$successful_event:example.org": {},
+                "$failed_event:example.org": {
+                  "error": "You are not allowed to send a message to this room."
                 }
               }
-            ]
+            }

changelogs/server_server/newsfragments/2560.clarification

@@ -0,0 +1 @@
+Fix the response format of the ``/send`` endpoint.