Enable CHANGE_FEED_WITH_START_TIME_POST_MERGE SDK capability (#48752)

tvaron3 · Copilot · web-flow · commit 51486dba7e23 · 2026-04-09T17:22:43.000-04:00
Enable the CHANGE_FEED_WITH_START_TIME_POST_MERGE capability flag in
SUPPORTED_CAPABILITIES so the backend allows IfModifiedSince headers
on merged partitions for change feed requests.

Co-authored-by: Copilot &lt;223556219+Copilot@users.noreply.github.com&gt;
diff --git a/sdk/cosmos/azure-cosmos/CHANGELOG.md b/sdk/cosmos/azure-cosmos/CHANGELOG.md
@@ -7,6 +7,7 @@
 #### Breaking Changes
 
 #### Bugs Fixed
+* Fixed an issue where change feed with `startFrom` point-in-time returned `400` on merged partitions by enabling the `CHANGE_FEED_WITH_START_TIME_POST_MERGE` SDK capability.
 
 #### Other Changes
 
diff --git a/sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/implementation/HttpConstants.java b/sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/implementation/HttpConstants.java
@@ -316,7 +316,7 @@ public static class SDKSupportedCapabilities {
         public static final String SUPPORTED_CAPABILITIES;
         public static final String SUPPORTED_CAPABILITIES_NONE;
         static {
-            SUPPORTED_CAPABILITIES = String.valueOf(PARTITION_MERGE);
+            SUPPORTED_CAPABILITIES = String.valueOf(PARTITION_MERGE | CHANGE_FEED_WITH_START_TIME_POST_MERGE);
             SUPPORTED_CAPABILITIES_NONE = String.valueOf(NONE);
         }
     }

Original file line number	Diff line number	Diff line change
`@@ -316,7 +316,7 @@ public static class SDKSupportedCapabilities {`
`316`	`316`	`public static final String SUPPORTED_CAPABILITIES;`
`317`	`317`	`public static final String SUPPORTED_CAPABILITIES_NONE;`
`318`	`318`	`static {`
`319`		`- SUPPORTED_CAPABILITIES = String.valueOf(PARTITION_MERGE);`
	`319`	`+ SUPPORTED_CAPABILITIES = String.valueOf(PARTITION_MERGE \| CHANGE_FEED_WITH_START_TIME_POST_MERGE);`
`320`	`320`	`SUPPORTED_CAPABILITIES_NONE = String.valueOf(NONE);`
`321`	`321`	`}`
`322`	`322`	`}`