diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/bulk.json b/rest-api-spec/src/main/resources/rest-api-spec/api/bulk.json
index 97bff093c1dac..19944da4fdee1 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/bulk.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/bulk.json
@@ -55,7 +55,7 @@
         "description": "If `true` then refresh the affected shards to make this operation visible to search, if `wait_for` then wait for a refresh to make this operation visible to search, if `false` (the default) then do nothing with refreshes."
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "timeout": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/create.json b/rest-api-spec/src/main/resources/rest-api-spec/api/create.json
index f96d157ab41e2..f2a847b18f733 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/create.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/create.json
@@ -52,7 +52,7 @@
         "description": "If `true` then refresh the affected shards to make this operation visible to search, if `wait_for` then wait for a refresh to make this operation visible to search, if `false` (the default) then do nothing with refreshes."
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "timeout": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/delete.json b/rest-api-spec/src/main/resources/rest-api-spec/api/delete.json
index 9fea79845dfed..43eb05f36a421 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/delete.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/delete.json
@@ -48,7 +48,7 @@
         "description": "If `true` then refresh the affected shards to make this operation visible to search, if `wait_for` then wait for a refresh to make this operation visible to search, if `false` (the default) then do nothing with refreshes."
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "timeout": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/exists.json b/rest-api-spec/src/main/resources/rest-api-spec/api/exists.json
index 30fc87d3f4cb4..a842b4685cb3f 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/exists.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/exists.json
@@ -51,7 +51,7 @@
         "description": "Refresh the shard containing the document before performing the operation"
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "_source": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/exists_source.json b/rest-api-spec/src/main/resources/rest-api-spec/api/exists_source.json
index 18edcf7f2c97b..82a8a4ceb2a07 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/exists_source.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/exists_source.json
@@ -47,7 +47,7 @@
         "description": "Refresh the shard containing the document before performing the operation"
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "_source": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/explain.json b/rest-api-spec/src/main/resources/rest-api-spec/api/explain.json
index 0315bee5042c5..7fe080ffd31da 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/explain.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/explain.json
@@ -76,7 +76,7 @@
         "description": "Query in the Lucene query string syntax"
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "_source": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/get.json b/rest-api-spec/src/main/resources/rest-api-spec/api/get.json
index aecdb5ce20b55..7912a4d319bf5 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/get.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/get.json
@@ -57,7 +57,7 @@
         "description": "Refresh the shard containing the document before performing the operation"
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "_source": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/get_source.json b/rest-api-spec/src/main/resources/rest-api-spec/api/get_source.json
index e5a6c3d4822a4..b1b760f1aa4c3 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/get_source.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/get_source.json
@@ -47,7 +47,7 @@
         "description": "Refresh the shard containing the document before performing the operation"
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "_source": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/graph.explore.json b/rest-api-spec/src/main/resources/rest-api-spec/api/graph.explore.json
index 0f687422e2cc7..4ad39df61f726 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/graph.explore.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/graph.explore.json
@@ -33,7 +33,7 @@
     },
     "params": {
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "timeout": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/index.json b/rest-api-spec/src/main/resources/rest-api-spec/api/index.json
index ea3f78958eb9d..51a9021540a25 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/index.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/index.json
@@ -72,7 +72,7 @@
         "description": "If `true` then refresh the affected shards to make this operation visible to search, if `wait_for` then wait for a refresh to make this operation visible to search, if `false` (the default) then do nothing with refreshes."
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "timeout": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/mget.json b/rest-api-spec/src/main/resources/rest-api-spec/api/mget.json
index 569f2506e7f3e..69606568736e8 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/mget.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/mget.json
@@ -65,7 +65,7 @@
         "description": "Refresh the shard containing the document before performing the operation"
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "_source": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/mtermvectors.json b/rest-api-spec/src/main/resources/rest-api-spec/api/mtermvectors.json
index 989f9977467be..3205f860b4df5 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/mtermvectors.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/mtermvectors.json
@@ -77,7 +77,7 @@
         "description": "Specify the node or shard the operation should be performed on (default: random) .Applies to all returned documents unless otherwise specified in body \"params\" or \"docs\"."
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value. Applies to all returned documents unless otherwise specified in body \"params\" or \"docs\"."
       },
       "realtime": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/open_point_in_time.json b/rest-api-spec/src/main/resources/rest-api-spec/api/open_point_in_time.json
index 79133e7e4759f..dc246cf273961 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/open_point_in_time.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/open_point_in_time.json
@@ -36,7 +36,7 @@
         "description": "Specify the node or shard the operation should be performed on (default: random)"
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "ignore_unavailable": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/search_shards.json b/rest-api-spec/src/main/resources/rest-api-spec/api/search_shards.json
index 08b928a027d20..7bed96457ea90 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/search_shards.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/search_shards.json
@@ -41,7 +41,7 @@
         "description": "Specify the node or shard the operation should be performed on (default: random)"
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "local": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/termvectors.json b/rest-api-spec/src/main/resources/rest-api-spec/api/termvectors.json
index c60f0ad2bd3e6..4bb2cf8538e9b 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/termvectors.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/termvectors.json
@@ -83,7 +83,7 @@
         "description": "Specify the node or shard the operation should be performed on (default: random)."
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value."
       },
       "realtime": {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/update.json b/rest-api-spec/src/main/resources/rest-api-spec/api/update.json
index d0e9bba53f207..b5476d1686148 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/update.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/update.json
@@ -74,7 +74,7 @@
         "description": "Specify how many times should the operation be retried when a conflict occurs (default: 0)"
       },
       "routing": {
-        "type": "string",
+        "type": "list",
         "description": "Specific routing value"
       },
       "timeout": {