diff --git a/compiler/crates/relay-codegen/tests/defer_stream/fixtures/fragment-with-stream-default-label.expected b/compiler/crates/relay-codegen/tests/defer_stream/fixtures/fragment-with-stream-default-label.expected
index 95222b6649848..a741b1fce7a72 100644
--- a/compiler/crates/relay-codegen/tests/defer_stream/fixtures/fragment-with-stream-default-label.expected
+++ b/compiler/crates/relay-codegen/tests/defer_stream/fixtures/fragment-with-stream-default-label.expected
@@ -8,7 +8,7 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1) {
+  actors @stream(initialCount: 1) {
     name
   }
 }
diff --git a/compiler/crates/relay-codegen/tests/defer_stream/fixtures/fragment-with-stream-default-label.graphql b/compiler/crates/relay-codegen/tests/defer_stream/fixtures/fragment-with-stream-default-label.graphql
index 23fa23b3e8e43..739db7de64c6a 100644
--- a/compiler/crates/relay-codegen/tests/defer_stream/fixtures/fragment-with-stream-default-label.graphql
+++ b/compiler/crates/relay-codegen/tests/defer_stream/fixtures/fragment-with-stream-default-label.graphql
@@ -7,7 +7,7 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1) {
+  actors @stream(initialCount: 1) {
     name
   }
 }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-defer-in-stream.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-defer-in-stream.expected
index 3d556e54b8851..2139b95fd1a88 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-defer-in-stream.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-defer-in-stream.expected
@@ -8,7 +8,7 @@ query fragmentWithDeferInStream_QueryWithFragmentWithStreamQuery($id: ID!) {
 
 fragment fragmentWithDeferInStream_FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: "StreamedActorsLabel") {
+  actors @stream(initialCount: 1, label: "StreamedActorsLabel") {
     ...fragmentWithDeferInStream_ActorFragment @defer
   }
 }
@@ -193,7 +193,7 @@ fragment fragmentWithDeferInStream_ActorFragment on Actor {
 
 fragment fragmentWithDeferInStream_FeedbackFragment on Feedback {
   id
-  actors @stream(label: "fragmentWithDeferInStream_FeedbackFragment$stream$StreamedActorsLabel", initial_count: 1) {
+  actors @stream(label: "fragmentWithDeferInStream_FeedbackFragment$stream$StreamedActorsLabel", initialCount: 1) {
     __typename
     ...fragmentWithDeferInStream_ActorFragment @defer(label: "fragmentWithDeferInStream_FeedbackFragment$defer$fragmentWithDeferInStream_ActorFragment")
     id
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-defer-in-stream.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-defer-in-stream.graphql
index 7886bae9ac370..d551db5e514b2 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-defer-in-stream.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-defer-in-stream.graphql
@@ -7,7 +7,7 @@ query fragmentWithDeferInStream_QueryWithFragmentWithStreamQuery($id: ID!) {
 
 fragment fragmentWithDeferInStream_FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: "StreamedActorsLabel") {
+  actors @stream(initialCount: 1, label: "StreamedActorsLabel") {
     ...fragmentWithDeferInStream_ActorFragment @defer
   }
 }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-stream.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-stream.expected
index 002bbb646c663..1b3e53770b1b2 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-stream.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-stream.expected
@@ -8,7 +8,7 @@ query fragmentWithStream_QueryWithFragmentWithStreamQuery($id: ID!) {
 
 fragment fragmentWithStream_FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: "StreamedActorsLabel") {
+  actors @stream(initialCount: 1, label: "StreamedActorsLabel") {
     name
   }
 }
@@ -173,7 +173,7 @@ query fragmentWithStream_QueryWithFragmentWithStreamQuery(
 
 fragment fragmentWithStream_FeedbackFragment on Feedback {
   id
-  actors @stream(label: "fragmentWithStream_FeedbackFragment$stream$StreamedActorsLabel", initial_count: 1) {
+  actors @stream(label: "fragmentWithStream_FeedbackFragment$stream$StreamedActorsLabel", initialCount: 1) {
     __typename
     name
     id
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-stream.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-stream.graphql
index e60f16cdf1a39..c9020d678df83 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-stream.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/fragment-with-stream.graphql
@@ -7,7 +7,7 @@ query fragmentWithStream_QueryWithFragmentWithStreamQuery($id: ID!) {
 
 fragment fragmentWithStream_FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: "StreamedActorsLabel") {
+  actors @stream(initialCount: 1, label: "StreamedActorsLabel") {
     name
   }
 }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/refetchable-fragment-with-connection-with-stream.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/refetchable-fragment-with-connection-with-stream.expected
index 330d00ea0ebc4..683a12d8c2fe3 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/refetchable-fragment-with-connection-with-stream.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/refetchable-fragment-with-connection-with-stream.expected
@@ -9,7 +9,7 @@ fragment refetchableFragmentWithConnectionWithStream_PaginationFragment on Node
   ... on User {
     name
     friends(after: $cursor, first: $count)
-      @stream_connection(key: "PaginationFragment_friends", initial_count: 1) {
+      @stream_connection(key: "PaginationFragment_friends", initialCount: 1) {
       edges {
         node {
           id
@@ -305,7 +305,7 @@ fragment refetchableFragmentWithConnectionWithStream_PaginationFragment_1G22uz o
   ... on User {
     name
     friends(after: $cursor, first: $count) {
-      edges @stream(label: "refetchableFragmentWithConnectionWithStream_PaginationFragment$stream$PaginationFragment_friends", initial_count: 1) {
+      edges @stream(label: "refetchableFragmentWithConnectionWithStream_PaginationFragment$stream$PaginationFragment_friends", initialCount: 1) {
         node {
           id
           __typename
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/refetchable-fragment-with-connection-with-stream.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/refetchable-fragment-with-connection-with-stream.graphql
index a46be98ae3ff9..bc89a07f01a2b 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/refetchable-fragment-with-connection-with-stream.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/refetchable-fragment-with-connection-with-stream.graphql
@@ -8,7 +8,7 @@ fragment refetchableFragmentWithConnectionWithStream_PaginationFragment on Node
   ... on User {
     name
     friends(after: $cursor, first: $count)
-      @stream_connection(key: "PaginationFragment_friends", initial_count: 1) {
+      @stream_connection(key: "PaginationFragment_friends", initialCount: 1) {
       edges {
         node {
           id
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_1.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_1.expected
index be19d3923866b..b585b6c837a59 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_1.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_1.expected
@@ -5,7 +5,7 @@ query selectionSetConflictInconsistentStreamUsage1Query {
     ... on User {
       friends {
         ... on FriendsConnection {
-          edges @stream(label: "hdijf", initial_count: 1) {
+          edges @stream(label: "hdijf", initialCount: 1) {
             node {
               name
             }
@@ -25,7 +25,7 @@ query selectionSetConflictInconsistentStreamUsage1Query {
 
   selection_set_conflict_inconsistent_stream_usage_1.graphql:7:11
     6 │         ... on FriendsConnection {
-    7 │           edges @stream(label: "hdijf", initial_count: 1) {
+    7 │           edges @stream(label: "hdijf", initialCount: 1) {
       │           ^^^^^
     8 │             node {
 
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_1.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_1.graphql
index 4e97124b440fd..ae506dfaf7429 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_1.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_1.graphql
@@ -4,7 +4,7 @@ query selectionSetConflictInconsistentStreamUsage1Query {
     ... on User {
       friends {
         ... on FriendsConnection {
-          edges @stream(label: "hdijf", initial_count: 1) {
+          edges @stream(label: "hdijf", initialCount: 1) {
             node {
               name
             }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_2.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_2.expected
index 29d689b89243b..18e73023db4e5 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_2.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_2.expected
@@ -5,13 +5,13 @@ query selectionSetConflictInconsistentStreamUsage2Query {
     ... on User {
       friends {
         ... on FriendsConnection {
-          edges @stream(label: "hdijf", initial_count: 1) {
+          edges @stream(label: "hdijf", initialCount: 1) {
             node {
               name
             }
           }
         }
-        edges @stream(label: "hkjdf", initial_count: 2) {
+        edges @stream(label: "hkjdf", initialCount: 2) {
           node {
             id
           }
@@ -25,7 +25,7 @@ query selectionSetConflictInconsistentStreamUsage2Query {
 
   selection_set_conflict_inconsistent_stream_usage_2.graphql:7:11
     6 │         ... on FriendsConnection {
-    7 │           edges @stream(label: "hdijf", initial_count: 1) {
+    7 │           edges @stream(label: "hdijf", initialCount: 1) {
       │           ^^^^^
     8 │             node {
 
@@ -33,6 +33,6 @@ query selectionSetConflictInconsistentStreamUsage2Query {
 
   selection_set_conflict_inconsistent_stream_usage_2.graphql:13:9
    12 │         }
-   13 │         edges @stream(label: "hkjdf", initial_count: 2) {
+   13 │         edges @stream(label: "hkjdf", initialCount: 2) {
       │         ^^^^^
    14 │           node {
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_2.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_2.graphql
index e69ddcbf87db8..1042d77fa9bcf 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_2.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_inconsistent_stream_usage_2.graphql
@@ -4,13 +4,13 @@ query selectionSetConflictInconsistentStreamUsage2Query {
     ... on User {
       friends {
         ... on FriendsConnection {
-          edges @stream(label: "hdijf", initial_count: 1) {
+          edges @stream(label: "hdijf", initialCount: 1) {
             node {
               name
             }
           }
         }
-        edges @stream(label: "hkjdf", initial_count: 2) {
+        edges @stream(label: "hkjdf", initialCount: 2) {
           node {
             id
           }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges.expected
index f69b6e967b75e..9330283b2f92e 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges.expected
@@ -3,7 +3,7 @@ query selectionSetConflictStreamOnNodesOrEdgesQuery {
   me {
     ... on User {
       friends {
-        edges @stream(label: "b", initial_count: 1) {
+        edges @stream(label: "b", initialCount: 1) {
           node {
             id
           }
@@ -167,7 +167,7 @@ QUERY:
 query selectionSetConflictStreamOnNodesOrEdgesQuery {
   me {
     friends {
-      edges @stream(label: "selectionSetConflictStreamOnNodesOrEdgesQuery$stream$b", initial_count: 1) {
+      edges @stream(label: "selectionSetConflictStreamOnNodesOrEdgesQuery$stream$b", initialCount: 1) {
         node {
           id
         }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges.graphql
index db0148987fcb8..e8902568b4a2d 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges.graphql
@@ -2,7 +2,7 @@ query selectionSetConflictStreamOnNodesOrEdgesQuery {
   me {
     ... on User {
       friends {
-        edges @stream(label: "b", initial_count: 1) {
+        edges @stream(label: "b", initialCount: 1) {
           node {
             id
           }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info.expected
index 42539774dc1e4..cb46571fafe82 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info.expected
@@ -9,7 +9,7 @@ query selectionSetConflictStreamOnNodesOrEdgesWithoutDeferOnPageInfoQuery {
             hasNextPage
           }
         }
-        edges @stream(label: "b", initial_count: 1) {
+        edges @stream(label: "b", initialCount: 1) {
           node {
             id
           }
@@ -212,7 +212,7 @@ query selectionSetConflictStreamOnNodesOrEdgesWithoutDeferOnPageInfoQuery {
       pageInfo {
         hasNextPage
       }
-      edges @stream(label: "selectionSetConflictStreamOnNodesOrEdgesWithoutDeferOnPageInfoQuery$stream$b", initial_count: 1) {
+      edges @stream(label: "selectionSetConflictStreamOnNodesOrEdgesWithoutDeferOnPageInfoQuery$stream$b", initialCount: 1) {
         node {
           id
         }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info.graphql
index 5622f4c32e72a..2b932153c1396 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info.graphql
@@ -8,7 +8,7 @@ query selectionSetConflictStreamOnNodesOrEdgesWithoutDeferOnPageInfoQuery {
             hasNextPage
           }
         }
-        edges @stream(label: "b", initial_count: 1) {
+        edges @stream(label: "b", initialCount: 1) {
           node {
             id
           }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info_and_page_info_alias.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info_and_page_info_alias.expected
index 076b93742a360..36ae58f1a4df5 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info_and_page_info_alias.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info_and_page_info_alias.expected
@@ -9,7 +9,7 @@ query selectionSetConflictStreamOnNodesOrEdgesWithoutDeferOnPageInfoAndPageInfoA
             hasNextPage
           }
         }
-        edges @stream(label: "b", initial_count: 1) {
+        edges @stream(label: "b", initialCount: 1) {
           node {
             id
           }
@@ -212,7 +212,7 @@ query selectionSetConflictStreamOnNodesOrEdgesWithoutDeferOnPageInfoAndPageInfoA
       pagination: pageInfo {
         hasNextPage
       }
-      edges @stream(label: "selectionSetConflictStreamOnNodesOrEdgesWithoutDeferOnPageInfoAndPageInfoAliasQuery$stream$b", initial_count: 1) {
+      edges @stream(label: "selectionSetConflictStreamOnNodesOrEdgesWithoutDeferOnPageInfoAndPageInfoAliasQuery$stream$b", initialCount: 1) {
         node {
           id
         }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info_and_page_info_alias.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info_and_page_info_alias.graphql
index c956d3b86fd3b..52fb05a8580c7 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info_and_page_info_alias.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_stream_on_nodes_or_edges_without_defer_on_page_info_and_page_info_alias.graphql
@@ -8,7 +8,7 @@ query selectionSetConflictStreamOnNodesOrEdgesWithoutDeferOnPageInfoAndPageInfoA
             hasNextPage
           }
         }
-        edges @stream(label: "b", initial_count: 1) {
+        edges @stream(label: "b", initialCount: 1) {
           node {
             id
           }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_valid_stream.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_valid_stream.expected
index ca94f2998cec2..31724edcdf7e0 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_valid_stream.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_valid_stream.expected
@@ -3,7 +3,7 @@ query selectionSetConflictValidStreamQuery {
   me {
     ... on User {
       friends {
-        edges @stream(label: "jkdhg", initial_count: 0) {
+        edges @stream(label: "jkdhg", initialCount: 0) {
           node {
             id
           }
@@ -167,7 +167,7 @@ QUERY:
 query selectionSetConflictValidStreamQuery {
   me {
     friends {
-      edges @stream(label: "selectionSetConflictValidStreamQuery$stream$jkdhg", initial_count: 0) {
+      edges @stream(label: "selectionSetConflictValidStreamQuery$stream$jkdhg", initialCount: 0) {
         node {
           id
         }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_valid_stream.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_valid_stream.graphql
index 414122e99e447..b1f17e144839e 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_valid_stream.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/selection_set_conflict_valid_stream.graphql
@@ -2,7 +2,7 @@ query selectionSetConflictValidStreamQuery {
   me {
     ... on User {
       friends {
-        edges @stream(label: "jkdhg", initial_count: 0) {
+        edges @stream(label: "jkdhg", initialCount: 0) {
           node {
             id
           }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-and-handle.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-and-handle.expected
index fceaef53b576a..c8447ca01c5a2 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-and-handle.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-and-handle.expected
@@ -7,7 +7,7 @@ query streamAndHandleQuery {
 
 fragment streamAndHandleFragment on Feedback {
   actors
-    @stream(label: "actors", if: true, initial_count: 0)
+    @stream(label: "actors", if: true, initialCount: 0)
     @__clientField(handle: "actors_handler") {
     name @__clientField(handle: "name_handler")
   }
@@ -169,7 +169,7 @@ query streamAndHandleQuery {
 }
 
 fragment streamAndHandleFragment on Feedback {
-  actors @stream(label: "streamAndHandleFragment$stream$actors", if: true, initial_count: 0) {
+  actors @stream(label: "streamAndHandleFragment$stream$actors", if: true, initialCount: 0) {
     __typename
     name
     id
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-and-handle.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-and-handle.graphql
index 0be41830dbe54..010ca4457f0cf 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-and-handle.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-and-handle.graphql
@@ -6,7 +6,7 @@ query streamAndHandleQuery {
 
 fragment streamAndHandleFragment on Feedback {
   actors
-    @stream(label: "actors", if: true, initial_count: 0)
+    @stream(label: "actors", if: true, initialCount: 0)
     @__clientField(handle: "actors_handler") {
     name @__clientField(handle: "name_handler")
   }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection-conditional.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection-conditional.expected
index c54f3d9efe97a..d948fbb5b6d1a 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection-conditional.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection-conditional.expected
@@ -5,9 +5,9 @@ query streamConnectionConditionalQuery($id: ID!, $cond: Boolean!) {
     ... on Story {
       comments(first: 10)
       @stream_connection(
-        use_customized_batch: $cond
+        useCustomizedBatch: $cond
         if: $cond
-        initial_count: 0
+        initialCount: 0
         key: "NodeQuery_comments"
       ) {
         edges {
@@ -359,7 +359,7 @@ query streamConnectionConditionalQuery(
     id
     ... on Story {
       comments(first: 10) {
-        edges @stream(label: "streamConnectionConditionalQuery$stream$NodeQuery_comments", if: $cond, initial_count: 0, use_customized_batch: $cond) {
+        edges @stream(label: "streamConnectionConditionalQuery$stream$NodeQuery_comments", if: $cond, initialCount: 0, useCustomizedBatch: $cond) {
           node {
             __typename
             id
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection-conditional.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection-conditional.graphql
index c73f0bc8e57eb..bf937a7fed149 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection-conditional.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection-conditional.graphql
@@ -4,9 +4,9 @@ query streamConnectionConditionalQuery($id: ID!, $cond: Boolean!) {
     ... on Story {
       comments(first: 10)
       @stream_connection(
-        use_customized_batch: $cond
+        useCustomizedBatch: $cond
         if: $cond
-        initial_count: 0
+        initialCount: 0
         key: "NodeQuery_comments"
       ) {
         edges {
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection.expected
index e24b01c449b7a..d59b8695de0e5 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection.expected
@@ -4,7 +4,7 @@ query streamConnection_NodeQuery($id: ID!) {
     id
     ... on Story {
       comments(first: 10)
-        @stream_connection(key: "NodeQuery_comments", initial_count: 0) {
+        @stream_connection(key: "NodeQuery_comments", initialCount: 0) {
         edges {
           node {
             actor {
@@ -399,7 +399,7 @@ query streamConnection_NodeQuery(
     id
     ... on Story {
       comments(first: 10) {
-        edges @stream(label: "streamConnection_NodeQuery$stream$NodeQuery_comments", initial_count: 0) {
+        edges @stream(label: "streamConnection_NodeQuery$stream$NodeQuery_comments", initialCount: 0) {
           node {
             actor {
               __typename
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection.graphql
index f572f9abf5957..73bd62e0133ea 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream-connection.graphql
@@ -3,7 +3,7 @@ query streamConnection_NodeQuery($id: ID!) {
     id
     ... on Story {
       comments(first: 10)
-        @stream_connection(key: "NodeQuery_comments", initial_count: 0) {
+        @stream_connection(key: "NodeQuery_comments", initialCount: 0) {
         edges {
           node {
             actor {
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream_if_arguments.expected b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream_if_arguments.expected
index 50b14943b9484..2df04cbcbaf1d 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream_if_arguments.expected
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream_if_arguments.expected
@@ -19,27 +19,27 @@ fragment streamIfArgumentsFragment on User
   setToFalse: { type: "Boolean", defaultValue: false }
 ) {
   withDefaultTrue: tasks
-    @stream(initial_count: 1, if: $defaultsToTrue, label: "defaultTrue") {
+    @stream(initialCount: 1, if: $defaultsToTrue, label: "defaultTrue") {
     __typename
   }
   withDefaultFalse: tasks
-    @stream(initial_count: 1, if: $defaultsToFalse, label: "defaultFalse") {
+    @stream(initialCount: 1, if: $defaultsToFalse, label: "defaultFalse") {
     __typename
   }
   setToTrue: tasks
-    @stream(initial_count: 1, if: $setToTrue, label: "setToTrue") {
+    @stream(initialCount: 1, if: $setToTrue, label: "setToTrue") {
     __typename
   }
   setToFalse: tasks
-    @stream(initial_count: 1, if: $setToFalse, label: "setToFalse") {
+    @stream(initialCount: 1, if: $setToFalse, label: "setToFalse") {
     __typename
   }
   withValueFromQueryDirectly: tasks
-    @stream(initial_count: 1, if: $valueFromQuery, label: "fromQueryDirectly") {
+    @stream(initialCount: 1, if: $valueFromQuery, label: "fromQueryDirectly") {
     __typename
   }
   withValueFromQueryViaArgDef: tasks
-    @stream(initial_count: 1, if: $setToValue, label: "fromQueryViaArg") {
+    @stream(initialCount: 1, if: $setToValue, label: "fromQueryViaArg") {
     __typename
   }
 }
@@ -282,22 +282,22 @@ query streamIfArgumentsQuery(
 }
 
 fragment streamIfArgumentsFragment_39RTKZ on User {
-  withDefaultTrue: tasks @stream(label: "streamIfArgumentsFragment$stream$defaultTrue", if: true, initial_count: 1) {
+  withDefaultTrue: tasks @stream(label: "streamIfArgumentsFragment$stream$defaultTrue", if: true, initialCount: 1) {
     __typename
   }
   withDefaultFalse: tasks {
     __typename
   }
-  setToTrue: tasks @stream(label: "streamIfArgumentsFragment$stream$setToTrue", if: true, initial_count: 1) {
+  setToTrue: tasks @stream(label: "streamIfArgumentsFragment$stream$setToTrue", if: true, initialCount: 1) {
     __typename
   }
   setToFalse: tasks {
     __typename
   }
-  withValueFromQueryDirectly: tasks @stream(label: "streamIfArgumentsFragment$stream$fromQueryDirectly", if: $valueFromQuery, initial_count: 1) {
+  withValueFromQueryDirectly: tasks @stream(label: "streamIfArgumentsFragment$stream$fromQueryDirectly", if: $valueFromQuery, initialCount: 1) {
     __typename
   }
-  withValueFromQueryViaArgDef: tasks @stream(label: "streamIfArgumentsFragment$stream$fromQueryViaArg", if: $valueFromQuery, initial_count: 1) {
+  withValueFromQueryViaArgDef: tasks @stream(label: "streamIfArgumentsFragment$stream$fromQueryViaArg", if: $valueFromQuery, initialCount: 1) {
     __typename
   }
 }
diff --git a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream_if_arguments.graphql b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream_if_arguments.graphql
index 0ab8458f480f9..ffc1e2ae9280a 100644
--- a/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream_if_arguments.graphql
+++ b/compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/stream_if_arguments.graphql
@@ -18,27 +18,27 @@ fragment streamIfArgumentsFragment on User
   setToFalse: { type: "Boolean", defaultValue: false }
 ) {
   withDefaultTrue: tasks
-    @stream(initial_count: 1, if: $defaultsToTrue, label: "defaultTrue") {
+    @stream(initialCount: 1, if: $defaultsToTrue, label: "defaultTrue") {
     __typename
   }
   withDefaultFalse: tasks
-    @stream(initial_count: 1, if: $defaultsToFalse, label: "defaultFalse") {
+    @stream(initialCount: 1, if: $defaultsToFalse, label: "defaultFalse") {
     __typename
   }
   setToTrue: tasks
-    @stream(initial_count: 1, if: $setToTrue, label: "setToTrue") {
+    @stream(initialCount: 1, if: $setToTrue, label: "setToTrue") {
     __typename
   }
   setToFalse: tasks
-    @stream(initial_count: 1, if: $setToFalse, label: "setToFalse") {
+    @stream(initialCount: 1, if: $setToFalse, label: "setToFalse") {
     __typename
   }
   withValueFromQueryDirectly: tasks
-    @stream(initial_count: 1, if: $valueFromQuery, label: "fromQueryDirectly") {
+    @stream(initialCount: 1, if: $valueFromQuery, label: "fromQueryDirectly") {
     __typename
   }
   withValueFromQueryViaArgDef: tasks
-    @stream(initial_count: 1, if: $setToValue, label: "fromQueryViaArg") {
+    @stream(initialCount: 1, if: $setToValue, label: "fromQueryViaArg") {
     __typename
   }
 }
diff --git a/compiler/crates/relay-lsp/src/completion/test.rs b/compiler/crates/relay-lsp/src/completion/test.rs
index 221bf35245969..e67d3002c2e87 100644
--- a/compiler/crates/relay-lsp/src/completion/test.rs
+++ b/compiler/crates/relay-lsp/src/completion/test.rs
@@ -247,7 +247,7 @@ fn empty_argument_list() {
     );
     assert_labels(
         items.unwrap(),
-        vec!["label", "initial_count", "if", "use_customized_batch"],
+        vec!["label", "initialCount", "if", "useCustomizedBatch"],
     );
 }
 
@@ -265,7 +265,7 @@ fn argument_name_without_value() {
     );
     assert_labels(
         items.unwrap(),
-        vec!["label", "initial_count", "if", "use_customized_batch"],
+        vec!["label", "initialCount", "if", "useCustomizedBatch"],
     );
 }
 
@@ -286,7 +286,7 @@ fn argument_name_with_existing_name() {
     );
     assert_labels(
         items.unwrap(),
-        vec!["label", "initial_count", "use_customized_batch"],
+        vec!["label", "initialCount", "useCustomizedBatch"],
     );
 }
 
diff --git a/compiler/crates/relay-schema/src/relay-extensions.graphql b/compiler/crates/relay-schema/src/relay-extensions.graphql
index 9cf77eedb57b9..46045aba95586 100644
--- a/compiler/crates/relay-schema/src/relay-extensions.graphql
+++ b/compiler/crates/relay-schema/src/relay-extensions.graphql
@@ -128,9 +128,9 @@ directive @stream_connection(
   filters: [String]
   handler: String
   label: String
-  initial_count: Int!
+  initialCount: Int!
   if: Boolean = true
-  use_customized_batch: Boolean = false
+  useCustomizedBatch: Boolean = false
   dynamicKey_UNSTABLE: String
 ) on FIELD
 
diff --git a/compiler/crates/relay-test-schema/src/testschema.graphql b/compiler/crates/relay-test-schema/src/testschema.graphql
index 841eb1c0418e5..403920e517a95 100644
--- a/compiler/crates/relay-test-schema/src/testschema.graphql
+++ b/compiler/crates/relay-test-schema/src/testschema.graphql
@@ -25,9 +25,9 @@ directive @defer(
 
 directive @stream(
   label: String!
-  initial_count: Int!
+  initialCount: Int!
   if: Boolean = true
-  use_customized_batch: Boolean = false
+  useCustomizedBatch: Boolean = false
 ) on FIELD
 
 directive @fetchable(field_name: String!) on OBJECT
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-default-label.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-default-label.expected
index 4b424a088dd26..0061be156e355 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-default-label.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-default-label.expected
@@ -8,7 +8,7 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1) {
+  actors @stream(initialCount: 1) {
     name
   }
 }
@@ -24,7 +24,7 @@ query QueryWithFragmentWithStream(
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(label: "FeedbackFragment$stream$actors", initial_count: 1) {
+  actors @stream(label: "FeedbackFragment$stream$actors", initialCount: 1) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-default-label.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-default-label.graphql
index 23fa23b3e8e43..739db7de64c6a 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-default-label.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-default-label.graphql
@@ -7,7 +7,7 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1) {
+  actors @stream(initialCount: 1) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-duplicate-label.invalid.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-duplicate-label.invalid.expected
index 37c40c910a975..7fe5f5834cdda 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-duplicate-label.invalid.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-duplicate-label.invalid.expected
@@ -9,10 +9,10 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: "actors") {
+  actors @stream(initialCount: 1, label: "actors") {
     name
   }
-  otherActors: actors @stream(initial_count: 1, label: "actors") {
+  otherActors: actors @stream(initialCount: 1, label: "actors") {
     # invalid: duplicate label
     name
   }
@@ -22,7 +22,7 @@ fragment FeedbackFragment on Feedback {
 
   fragment-with-stream-duplicate-label.invalid.graphql:11:10
    10 │   id
-   11 │   actors @stream(initial_count: 1, label: "actors") {
+   11 │   actors @stream(initialCount: 1, label: "actors") {
       │          ^^^^^^^
    12 │     name
 
@@ -30,6 +30,6 @@ fragment FeedbackFragment on Feedback {
 
   fragment-with-stream-duplicate-label.invalid.graphql:14:23
    13 │   }
-   14 │   otherActors: actors @stream(initial_count: 1, label: "actors") {
+   14 │   otherActors: actors @stream(initialCount: 1, label: "actors") {
       │                       ^^^^^^^
    15 │     # invalid: duplicate label
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-duplicate-label.invalid.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-duplicate-label.invalid.graphql
index 6f0d3488b2cb9..a05f524d1de46 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-duplicate-label.invalid.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-duplicate-label.invalid.graphql
@@ -8,10 +8,10 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: "actors") {
+  actors @stream(initialCount: 1, label: "actors") {
     name
   }
-  otherActors: actors @stream(initial_count: 1, label: "actors") {
+  otherActors: actors @stream(initialCount: 1, label: "actors") {
     # invalid: duplicate label
     name
   }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-if-arg.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-if-arg.expected
index 07a4e1cfba531..d3db2ff831380 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-if-arg.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-if-arg.expected
@@ -9,7 +9,7 @@ query QueryWithFragmentWithStream($id: ID!, $enableStream: Boolean) {
 fragment FeedbackFragment on Feedback {
   id
   actors
-    @stream(initial_count: 1, label: "StreamedActorsLabel", if: $enableStream) {
+    @stream(initialCount: 1, label: "StreamedActorsLabel", if: $enableStream) {
     name
   }
 }
@@ -26,7 +26,7 @@ query QueryWithFragmentWithStream(
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(label: "FeedbackFragment$stream$StreamedActorsLabel", if: $enableStream, initial_count: 1) {
+  actors @stream(label: "FeedbackFragment$stream$StreamedActorsLabel", if: $enableStream, initialCount: 1) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-if-arg.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-if-arg.graphql
index 20ae2c07f0bcf..266ebda30663d 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-if-arg.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-if-arg.graphql
@@ -8,7 +8,7 @@ query QueryWithFragmentWithStream($id: ID!, $enableStream: Boolean) {
 fragment FeedbackFragment on Feedback {
   id
   actors
-    @stream(initial_count: 1, label: "StreamedActorsLabel", if: $enableStream) {
+    @stream(initialCount: 1, label: "StreamedActorsLabel", if: $enableStream) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-initial-count-arg.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-initial-count-arg.expected
index 4c128c9f3f139..1f8aade373550 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-initial-count-arg.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-initial-count-arg.expected
@@ -8,7 +8,7 @@ query QueryWithFragmentWithStream($id: ID!, $initialCount: Int) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: $initialCount, label: "StreamedActorsLabel") {
+  actors @stream(initialCount: $initialCount, label: "StreamedActorsLabel") {
     name
   }
 }
@@ -25,7 +25,7 @@ query QueryWithFragmentWithStream(
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(label: "FeedbackFragment$stream$StreamedActorsLabel", initial_count: $initialCount) {
+  actors @stream(label: "FeedbackFragment$stream$StreamedActorsLabel", initialCount: $initialCount) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-initial-count-arg.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-initial-count-arg.graphql
index 9e689d6875cb5..338a8274a7ed7 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-initial-count-arg.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-initial-count-arg.graphql
@@ -7,7 +7,7 @@ query QueryWithFragmentWithStream($id: ID!, $initialCount: Int) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: $initialCount, label: "StreamedActorsLabel") {
+  actors @stream(initialCount: $initialCount, label: "StreamedActorsLabel") {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-missing-initial-count-arg.invalid.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-missing-initial-count-arg.invalid.expected
index e8b5acc305d89..9e66097730c87 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-missing-initial-count-arg.invalid.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-missing-initial-count-arg.invalid.expected
@@ -15,7 +15,7 @@ fragment FeedbackFragment on Feedback {
   }
 }
 ==================================== ERROR ====================================
-✖︎ Missing required argument: `initial_count`
+✖︎ Missing required argument: `initialCount`
 
   fragment-with-stream-missing-initial-count-arg.invalid.graphql:11:11
    10 │   id
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-on-scalar-field.invalid.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-on-scalar-field.invalid.expected
index fe338e6a8ba90..d1b7e4edc6d6d 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-on-scalar-field.invalid.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-on-scalar-field.invalid.expected
@@ -9,13 +9,13 @@ query QueryWithFragmentWithStream($id: ID!, $label: String!) {
 
 fragment UserFragment on User {
   id
-  name @stream(initial_count: 1, label: $label)
+  name @stream(initialCount: 1, label: $label)
 }
 ==================================== ERROR ====================================
 ✖︎ Invalid use of @stream on scalar field 'name'
 
   fragment-with-stream-on-scalar-field.invalid.graphql:11:8
    10 │   id
-   11 │   name @stream(initial_count: 1, label: $label)
+   11 │   name @stream(initialCount: 1, label: $label)
       │        ^^^^^^^
    12 │ }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-on-scalar-field.invalid.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-on-scalar-field.invalid.graphql
index 5ee3aa3cc33fc..907553dc9f516 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-on-scalar-field.invalid.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-on-scalar-field.invalid.graphql
@@ -8,5 +8,5 @@ query QueryWithFragmentWithStream($id: ID!, $label: String!) {
 
 fragment UserFragment on User {
   id
-  name @stream(initial_count: 1, label: $label)
+  name @stream(initialCount: 1, label: $label)
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-statically-disabled.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-statically-disabled.expected
index fdcdc1f94f927..18a1d123489f1 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-statically-disabled.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-statically-disabled.expected
@@ -8,7 +8,7 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: "StreamedActorsLabel", if: false) {
+  actors @stream(initialCount: 1, label: "StreamedActorsLabel", if: false) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-statically-disabled.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-statically-disabled.graphql
index cc529d908f6db..9fb1e0e3212d6 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-statically-disabled.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-statically-disabled.graphql
@@ -7,7 +7,7 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: "StreamedActorsLabel", if: false) {
+  actors @stream(initialCount: 1, label: "StreamedActorsLabel", if: false) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-use_customized_batch-arg.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-use_customized_batch-arg.expected
index e63411c2c5e3f..f7e18f6a86691 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-use_customized_batch-arg.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-use_customized_batch-arg.expected
@@ -11,9 +11,9 @@ fragment FeedbackFragment on Feedback {
   actors
     @stream(
       if: true
-      initial_count: 1
+      initialCount: 1
       label: "StreamedActorsLabel"
-      use_customized_batch: $useCustomizedBatch
+      useCustomizedBatch: $useCustomizedBatch
     ) {
     name
   }
@@ -31,7 +31,7 @@ query QueryWithFragmentWithStream(
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(label: "FeedbackFragment$stream$StreamedActorsLabel", if: true, initial_count: 1, use_customized_batch: $useCustomizedBatch) {
+  actors @stream(label: "FeedbackFragment$stream$StreamedActorsLabel", if: true, initialCount: 1, useCustomizedBatch: $useCustomizedBatch) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-use_customized_batch-arg.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-use_customized_batch-arg.graphql
index 5c0f7c15b697e..b252e2ba8dfbe 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-use_customized_batch-arg.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-use_customized_batch-arg.graphql
@@ -10,9 +10,9 @@ fragment FeedbackFragment on Feedback {
   actors
     @stream(
       if: true
-      initial_count: 1
+      initialCount: 1
       label: "StreamedActorsLabel"
-      use_customized_batch: $useCustomizedBatch
+      useCustomizedBatch: $useCustomizedBatch
     ) {
     name
   }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-variable-label.invalid.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-variable-label.invalid.expected
index 7c03a46f98759..de2cc3bf22754 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-variable-label.invalid.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-variable-label.invalid.expected
@@ -9,7 +9,7 @@ query QueryWithFragmentWithStream($id: ID!, $label: String!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: $label) {
+  actors @stream(initialCount: 1, label: $label) {
     name
   }
 }
@@ -18,6 +18,6 @@ fragment FeedbackFragment on Feedback {
 
   fragment-with-stream-variable-label.invalid.graphql:11:10
    10 │   id
-   11 │   actors @stream(initial_count: 1, label: $label) {
+   11 │   actors @stream(initialCount: 1, label: $label) {
       │          ^^^^^^^
    12 │     name
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-variable-label.invalid.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-variable-label.invalid.graphql
index 0877996f4bd7b..9d6f748019d5d 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-variable-label.invalid.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream-variable-label.invalid.graphql
@@ -8,7 +8,7 @@ query QueryWithFragmentWithStream($id: ID!, $label: String!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: $label) {
+  actors @stream(initialCount: 1, label: $label) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream.expected
index 61c9e8b532e49..2c4055bc32bc2 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream.expected
@@ -8,7 +8,7 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: "StreamedActorsLabel") {
+  actors @stream(initialCount: 1, label: "StreamedActorsLabel") {
     name
   }
 }
@@ -24,7 +24,7 @@ query QueryWithFragmentWithStream(
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(label: "FeedbackFragment$stream$StreamedActorsLabel", initial_count: 1) {
+  actors @stream(label: "FeedbackFragment$stream$StreamedActorsLabel", initialCount: 1) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream.graphql
index 8891fba1b9c8d..ceb87c5700edc 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/fragment-with-stream.graphql
@@ -7,7 +7,7 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  actors @stream(initial_count: 1, label: "StreamedActorsLabel") {
+  actors @stream(initialCount: 1, label: "StreamedActorsLabel") {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/query-with-stream.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/query-with-stream.expected
index 94b95aa77dd22..99d8ff40f48c6 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/query-with-stream.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/query-with-stream.expected
@@ -2,7 +2,7 @@
 query QueryWithStream($id: ID!) {
   node(id: $id) {
     ... on Feedback {
-      actors @stream(initial_count: 1, label: "StreamedActorsLabel") {
+      actors @stream(initialCount: 1, label: "StreamedActorsLabel") {
         name
       }
     }
@@ -14,7 +14,7 @@ query QueryWithStream(
 ) {
   node(id: $id) {
     ... on Feedback {
-      actors @stream(label: "QueryWithStream$stream$StreamedActorsLabel", initial_count: 1) {
+      actors @stream(label: "QueryWithStream$stream$StreamedActorsLabel", initialCount: 1) {
         name
       }
     }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/query-with-stream.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/query-with-stream.graphql
index 2b7d7173527d1..cb244a79f1267 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/query-with-stream.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/query-with-stream.graphql
@@ -1,7 +1,7 @@
 query QueryWithStream($id: ID!) {
   node(id: $id) {
     ... on Feedback {
-      actors @stream(initial_count: 1, label: "StreamedActorsLabel") {
+      actors @stream(initialCount: 1, label: "StreamedActorsLabel") {
         name
       }
     }
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/stream.invalid.expected b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/stream.invalid.expected
index 4d392cfd59708..e5a18b3a14b11 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/stream.invalid.expected
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/stream.invalid.expected
@@ -3,7 +3,7 @@
 
 fragment FeedbackFragment on Feedback {
   id
-  actor @stream(initial_count: 1) {
+  actor @stream(initialCount: 1) {
     name
   }
 }
@@ -12,6 +12,6 @@ fragment FeedbackFragment on Feedback {
 
   stream.invalid.graphql:5:9
     4 │   id
-    5 │   actor @stream(initial_count: 1) {
+    5 │   actor @stream(initialCount: 1) {
       │         ^^^^^^^
     6 │     name
diff --git a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/stream.invalid.graphql b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/stream.invalid.graphql
index b8e9a950fe4fc..5c640c998741a 100644
--- a/compiler/crates/relay-transforms/tests/defer_stream/fixtures/stream.invalid.graphql
+++ b/compiler/crates/relay-transforms/tests/defer_stream/fixtures/stream.invalid.graphql
@@ -2,7 +2,7 @@
 
 fragment FeedbackFragment on Feedback {
   id
-  actor @stream(initial_count: 1) {
+  actor @stream(initialCount: 1) {
     name
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-fragment-with-connection-with-stream.expected b/compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-fragment-with-connection-with-stream.expected
index ddce6f7a336e3..2541e5cf73437 100644
--- a/compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-fragment-with-connection-with-stream.expected
+++ b/compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-fragment-with-connection-with-stream.expected
@@ -9,7 +9,7 @@ fragment PaginationFragment on Node
   ... on User {
     name
     friends(after: $cursor, first: $count)
-      @stream_connection(key: "PaginationFragment_friends", initial_count: 1) {
+      @stream_connection(key: "PaginationFragment_friends", initialCount: 1) {
       edges {
         node {
           id
@@ -73,7 +73,7 @@ fragment PaginationFragment on Node @refetchable(queryName: "RefetchableFragment
   ... on User {
     name
     friends(after: $cursor, first: $count) @__clientField(key: "PaginationFragment_friends", handle: "connection", filters: null, dynamicKey_UNSTABLE: null) {
-      edges @stream(label: "PaginationFragment_friends", initial_count: 1) {
+      edges @stream(label: "PaginationFragment_friends", initialCount: 1) {
         node {
           id
         }
diff --git a/compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-fragment-with-connection-with-stream.graphql b/compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-fragment-with-connection-with-stream.graphql
index e6fc5872ef07d..a4cf016c7d77a 100644
--- a/compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-fragment-with-connection-with-stream.graphql
+++ b/compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-fragment-with-connection-with-stream.graphql
@@ -8,7 +8,7 @@ fragment PaginationFragment on Node
   ... on User {
     name
     friends(after: $cursor, first: $count)
-      @stream_connection(key: "PaginationFragment_friends", initial_count: 1) {
+      @stream_connection(key: "PaginationFragment_friends", initialCount: 1) {
       edges {
         node {
           id
diff --git a/compiler/crates/relay-transforms/tests/skip_unused_variables/fixtures/kitchen-sink.expected b/compiler/crates/relay-transforms/tests/skip_unused_variables/fixtures/kitchen-sink.expected
index 7cbd27d973980..3b954212f932a 100644
--- a/compiler/crates/relay-transforms/tests/skip_unused_variables/fixtures/kitchen-sink.expected
+++ b/compiler/crates/relay-transforms/tests/skip_unused_variables/fixtures/kitchen-sink.expected
@@ -54,7 +54,7 @@ query StreamQuerry($RELAY_INCREMENTAL_DELIVERY: Boolean!) {
   node(id: 4) {
     id
     ... on Feedback {
-      actors @stream(if: $RELAY_INCREMENTAL_DELIVERY, label: "foo", initial_count: 3) {
+      actors @stream(if: $RELAY_INCREMENTAL_DELIVERY, label: "foo", initialCount: 3) {
         name
       }
     }
@@ -78,7 +78,7 @@ query StreamQuerry(
   node(id: 4) {
     id
     ... on Feedback {
-      actors @stream(if: $RELAY_INCREMENTAL_DELIVERY, label: "foo", initial_count: 3) {
+      actors @stream(if: $RELAY_INCREMENTAL_DELIVERY, label: "foo", initialCount: 3) {
         name
       }
     }
diff --git a/compiler/crates/relay-transforms/tests/skip_unused_variables/fixtures/kitchen-sink.graphql b/compiler/crates/relay-transforms/tests/skip_unused_variables/fixtures/kitchen-sink.graphql
index 16577bd68b6dd..19ad1dec6ad0e 100644
--- a/compiler/crates/relay-transforms/tests/skip_unused_variables/fixtures/kitchen-sink.graphql
+++ b/compiler/crates/relay-transforms/tests/skip_unused_variables/fixtures/kitchen-sink.graphql
@@ -53,7 +53,7 @@ query StreamQuerry($RELAY_INCREMENTAL_DELIVERY: Boolean!) {
   node(id: 4) {
     id
     ... on Feedback {
-      actors @stream(if: $RELAY_INCREMENTAL_DELIVERY, label: "foo", initial_count: 3) {
+      actors @stream(if: $RELAY_INCREMENTAL_DELIVERY, label: "foo", initialCount: 3) {
         name
       }
     }
diff --git a/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection-no-label.expected b/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection-no-label.expected
index 96ceba0afdd37..12cc24c847dbf 100644
--- a/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection-no-label.expected
+++ b/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection-no-label.expected
@@ -4,7 +4,7 @@ query NodeQuery($id: ID!) {
     id
     ... on Story {
       comments(first: 10)
-        @stream_connection(key: "NodeQuery_comments", initial_count: 0) {
+        @stream_connection(key: "NodeQuery_comments", initialCount: 0) {
         edges {
           node {
             actor {
@@ -47,7 +47,7 @@ query NodeQuery(
     id
     ... on Story {
       comments(first: 10) @__clientField(key: "NodeQuery_comments", handle: "connection", filters: null, dynamicKey_UNSTABLE: null) {
-        edges @stream(label: "NodeQuery_comments", initial_count: 0) {
+        edges @stream(label: "NodeQuery_comments", initialCount: 0) {
           node {
             actor {
               name
diff --git a/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection-no-label.graphql b/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection-no-label.graphql
index e688708be3259..14406dcf91753 100644
--- a/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection-no-label.graphql
+++ b/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection-no-label.graphql
@@ -3,7 +3,7 @@ query NodeQuery($id: ID!) {
     id
     ... on Story {
       comments(first: 10)
-        @stream_connection(key: "NodeQuery_comments", initial_count: 0) {
+        @stream_connection(key: "NodeQuery_comments", initialCount: 0) {
         edges {
           node {
             actor {
diff --git a/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection.expected b/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection.expected
index e279dc6f8b7e3..eee7c86f07878 100644
--- a/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection.expected
+++ b/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection.expected
@@ -6,7 +6,7 @@ query NodeQuery($id: ID!) {
       comments(first: 10)
         @stream_connection(
           key: "NodeQuery_comments"
-          initial_count: 0
+          initialCount: 0
           label: "comments"
         ) {
         edges {
@@ -51,7 +51,7 @@ query NodeQuery(
     id
     ... on Story {
       comments(first: 10) @__clientField(key: "NodeQuery_comments", handle: "connection", filters: null, dynamicKey_UNSTABLE: null) {
-        edges @stream(label: "NodeQuery_comments", initial_count: 0) {
+        edges @stream(label: "NodeQuery_comments", initialCount: 0) {
           node {
             actor {
               name
diff --git a/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection.graphql b/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection.graphql
index 85b2df8960abc..a635f314c224d 100644
--- a/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection.graphql
+++ b/compiler/crates/relay-transforms/tests/transform_connections/fixtures/stream-connection.graphql
@@ -5,7 +5,7 @@ query NodeQuery($id: ID!) {
       comments(first: 10)
         @stream_connection(
           key: "NodeQuery_comments"
-          initial_count: 0
+          initialCount: 0
           label: "comments"
         ) {
         edges {
diff --git a/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-edges.invalid.expected b/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-edges.invalid.expected
index 2568aa2448730..b89be4b64e55f 100644
--- a/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-edges.invalid.expected
+++ b/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-edges.invalid.expected
@@ -5,7 +5,7 @@ query NodeQuery($id: ID!) {
     id
     ... on Story {
       comments(first: 10)
-        @stream_connection(key: "NodeQuery_comments", initial_count: 0) {
+        @stream_connection(key: "NodeQuery_comments", initialCount: 0) {
         commentEdges: edges {
           node {
             actor {
@@ -24,7 +24,7 @@ query NodeQuery($id: ID!) {
 ✖︎ @stream_connection does not support aliasing the 'edges' field.
 
   stream-connection-with-aliased-edges.invalid.graphql:8:23
-    7 │         @stream_connection(key: "NodeQuery_comments", initial_count: 0) {
+    7 │         @stream_connection(key: "NodeQuery_comments", initialCount: 0) {
     8 │         commentEdges: edges {
       │                       ^^^^^
     9 │           node {
diff --git a/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-edges.invalid.graphql b/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-edges.invalid.graphql
index d0aab1efddabc..fd1e797aae68e 100644
--- a/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-edges.invalid.graphql
+++ b/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-edges.invalid.graphql
@@ -4,7 +4,7 @@ query NodeQuery($id: ID!) {
     id
     ... on Story {
       comments(first: 10)
-        @stream_connection(key: "NodeQuery_comments", initial_count: 0) {
+        @stream_connection(key: "NodeQuery_comments", initialCount: 0) {
         commentEdges: edges {
           node {
             actor {
diff --git a/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-page-info.invalid.expected b/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-page-info.invalid.expected
index 0e5eb11245c42..e2bc851831b1d 100644
--- a/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-page-info.invalid.expected
+++ b/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-page-info.invalid.expected
@@ -5,7 +5,7 @@ query NodeQuery($id: ID!) {
     id
     ... on Story {
       comments(first: 10)
-        @stream_connection(key: "NodeQuery_comments", initial_count: 0) {
+        @stream_connection(key: "NodeQuery_comments", initialCount: 0) {
         edges {
           node {
             actor {
diff --git a/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-page-info.invalid.graphql b/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-page-info.invalid.graphql
index 07452848d1db5..9252ecd1319c7 100644
--- a/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-page-info.invalid.graphql
+++ b/compiler/crates/relay-transforms/tests/validate_connections/fixtures/stream-connection-with-aliased-page-info.invalid.graphql
@@ -4,7 +4,7 @@ query NodeQuery($id: ID!) {
     id
     ... on Story {
       comments(first: 10)
-        @stream_connection(key: "NodeQuery_comments", initial_count: 0) {
+        @stream_connection(key: "NodeQuery_comments", initialCount: 0) {
         edges {
           node {
             actor {
diff --git a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-child-of-client.invalid.expected b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-child-of-client.invalid.expected
index 71e9b5d1152c7..f581b57be4a83 100644
--- a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-child-of-client.invalid.expected
+++ b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-child-of-client.invalid.expected
@@ -11,7 +11,7 @@ fragment FeedbackFragment on Feedback {
   id
   foo {
     bar {
-      users @stream(initial_count: 1, label: "StreamedActorsLabel") {
+      users @stream(initialCount: 1, label: "StreamedActorsLabel") {
         id
         name
       }
@@ -36,7 +36,7 @@ type Bar {
 
   fragment-with-stream-child-of-client.invalid.graphql:13:13
    12 │     bar {
-   13 │       users @stream(initial_count: 1, label: "StreamedActorsLabel") {
+   13 │       users @stream(initialCount: 1, label: "StreamedActorsLabel") {
       │             ^^^^^^^
    14 │         id
 
diff --git a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-child-of-client.invalid.graphql b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-child-of-client.invalid.graphql
index 49880cbacd8cc..ce5213ab3d448 100644
--- a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-child-of-client.invalid.graphql
+++ b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-child-of-client.invalid.graphql
@@ -10,7 +10,7 @@ fragment FeedbackFragment on Feedback {
   id
   foo {
     bar {
-      users @stream(initial_count: 1, label: "StreamedActorsLabel") {
+      users @stream(initialCount: 1, label: "StreamedActorsLabel") {
         id
         name
       }
diff --git a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-on-client.invalid.expected b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-on-client.invalid.expected
index 0a8232ffb6cbd..f15daf0a8c3e7 100644
--- a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-on-client.invalid.expected
+++ b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-on-client.invalid.expected
@@ -9,7 +9,7 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  foos @stream(initial_count: 1, label: "StreamedActorsLabel") {
+  foos @stream(initialCount: 1, label: "StreamedActorsLabel") {
     bar
   }
 }
@@ -28,7 +28,7 @@ type Foo {
 
   fragment-with-stream-on-client.invalid.graphql:11:8
    10 │   id
-   11 │   foos @stream(initial_count: 1, label: "StreamedActorsLabel") {
+   11 │   foos @stream(initialCount: 1, label: "StreamedActorsLabel") {
       │        ^^^^^^^
    12 │     bar
 
@@ -36,6 +36,6 @@ type Foo {
 
   fragment-with-stream-on-client.invalid.graphql:11:3
    10 │   id
-   11 │   foos @stream(initial_count: 1, label: "StreamedActorsLabel") {
+   11 │   foos @stream(initialCount: 1, label: "StreamedActorsLabel") {
       │   ^^^^
    12 │     bar
diff --git a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-on-client.invalid.graphql b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-on-client.invalid.graphql
index 045192ee83bfa..5a45d44cf6645 100644
--- a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-on-client.invalid.graphql
+++ b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/fragment-with-stream-on-client.invalid.graphql
@@ -8,7 +8,7 @@ query QueryWithFragmentWithStream($id: ID!) {
 
 fragment FeedbackFragment on Feedback {
   id
-  foos @stream(initial_count: 1, label: "StreamedActorsLabel") {
+  foos @stream(initialCount: 1, label: "StreamedActorsLabel") {
     bar
   }
 }
diff --git a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/stream-connection-on-client.invalid.expected b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/stream-connection-on-client.invalid.expected
index 960dcba4a0f30..ef9e5276bbcb4 100644
--- a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/stream-connection-on-client.invalid.expected
+++ b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/stream-connection-on-client.invalid.expected
@@ -7,7 +7,7 @@ query NodeQuery($id: ID!) {
       clientComments(first: 10)
         @stream_connection(
           key: "NodeQuery_clientComments"
-          initial_count: 0
+          initialCount: 0
           label: "comments"
         ) {
         edges {
diff --git a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/stream-connection-on-client.invalid.graphql b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/stream-connection-on-client.invalid.graphql
index 965cb04e82ca9..7e675cbd21c30 100644
--- a/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/stream-connection-on-client.invalid.graphql
+++ b/compiler/crates/relay-transforms/tests/validate_server_only_directives/fixtures/stream-connection-on-client.invalid.graphql
@@ -6,7 +6,7 @@ query NodeQuery($id: ID!) {
       clientComments(first: 10)
         @stream_connection(
           key: "NodeQuery_clientComments"
-          initial_count: 0
+          initialCount: 0
           label: "comments"
         ) {
         edges {
diff --git a/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream-connection.expected b/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream-connection.expected
index 4067ea5553524..260df907d798b 100644
--- a/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream-connection.expected
+++ b/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream-connection.expected
@@ -4,7 +4,7 @@ query TestDefer @raw_response_type {
     ... on User {
       name
       friends(first: 10)
-        @stream_connection(key: "TestDefer_friends", initial_count: 0) {
+        @stream_connection(key: "TestDefer_friends", initialCount: 0) {
         edges {
           node {
             actor {
diff --git a/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream-connection.graphql b/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream-connection.graphql
index d318b27e3e3f0..88832391bf57e 100644
--- a/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream-connection.graphql
+++ b/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream-connection.graphql
@@ -3,7 +3,7 @@ query TestDefer @raw_response_type {
     ... on User {
       name
       friends(first: 10)
-        @stream_connection(key: "TestDefer_friends", initial_count: 0) {
+        @stream_connection(key: "TestDefer_friends", initialCount: 0) {
         edges {
           node {
             actor {
diff --git a/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream.expected b/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream.expected
index c1146f1c14df1..6ed3e0c66c620 100644
--- a/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream.expected
+++ b/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream.expected
@@ -6,7 +6,7 @@ query TestStream @raw_response_type {
       friends(first: 10)
         @stream_connection(
           key: "PaginationFragment_friends"
-          initial_count: 1
+          initialCount: 1
         ) {
         edges {
           node {
diff --git a/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream.graphql b/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream.graphql
index 4d2caacc587ba..0f5e1b4d9b8c8 100644
--- a/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream.graphql
+++ b/compiler/crates/relay-typegen/tests/generate_flow/fixtures/query-with-stream.graphql
@@ -5,7 +5,7 @@ query TestStream @raw_response_type {
       friends(first: 10)
         @stream_connection(
           key: "PaginationFragment_friends"
-          initial_count: 1
+          initialCount: 1
         ) {
         edges {
           node {
diff --git a/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream-connection.expected b/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream-connection.expected
index 35ca87a7a8c49..9390fcf2a34fb 100644
--- a/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream-connection.expected
+++ b/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream-connection.expected
@@ -4,7 +4,7 @@ query TestDefer @raw_response_type {
     ... on User {
       name
       friends(first: 10)
-        @stream_connection(key: "TestDefer_friends", initial_count: 0) {
+        @stream_connection(key: "TestDefer_friends", initialCount: 0) {
         edges {
           node {
             actor {
diff --git a/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream-connection.graphql b/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream-connection.graphql
index d318b27e3e3f0..88832391bf57e 100644
--- a/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream-connection.graphql
+++ b/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream-connection.graphql
@@ -3,7 +3,7 @@ query TestDefer @raw_response_type {
     ... on User {
       name
       friends(first: 10)
-        @stream_connection(key: "TestDefer_friends", initial_count: 0) {
+        @stream_connection(key: "TestDefer_friends", initialCount: 0) {
         edges {
           node {
             actor {
diff --git a/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream.expected b/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream.expected
index ddae6797f8bcb..6318fe817e227 100644
--- a/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream.expected
+++ b/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream.expected
@@ -6,7 +6,7 @@ query TestStream @raw_response_type {
       friends(first: 10)
         @stream_connection(
           key: "PaginationFragment_friends"
-          initial_count: 1
+          initialCount: 1
         ) {
         edges {
           node {
diff --git a/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream.graphql b/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream.graphql
index 4d2caacc587ba..0f5e1b4d9b8c8 100644
--- a/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream.graphql
+++ b/compiler/crates/relay-typegen/tests/generate_typescript/fixtures/query-with-stream.graphql
@@ -5,7 +5,7 @@ query TestStream @raw_response_type {
       friends(first: 10)
         @stream_connection(
           key: "PaginationFragment_friends"
-          initial_count: 1
+          initialCount: 1
         ) {
         edges {
           node {