diff --git a/output/openapi/elasticsearch-serverless-openapi.json b/output/openapi/elasticsearch-serverless-openapi.json
index 3ffcbb3d11..17bee8cb14 100644
--- a/output/openapi/elasticsearch-serverless-openapi.json
+++ b/output/openapi/elasticsearch-serverless-openapi.json
@@ -53247,6 +53247,9 @@
           },
           "location": {
             "$ref": "#/components/schemas/ml._types:TrainedModelLocation"
+          },
+          "prefix_strings": {
+            "$ref": "#/components/schemas/ml._types:TrainedModelPrefixStrings"
           }
         },
         "required": [
@@ -53719,6 +53722,23 @@
           "name"
         ]
       },
+      "ml._types:TrainedModelPrefixStrings": {
+        "type": "object",
+        "properties": {
+          "ingest": {
+            "description": "String prepended to input at ingest",
+            "type": "string"
+          },
+          "search": {
+            "description": "String prepended to input at search",
+            "type": "string"
+          }
+        },
+        "required": [
+          "ingest",
+          "search"
+        ]
+      },
       "ml._types:TrainedModelStats": {
         "type": "object",
         "properties": {
diff --git a/output/schema/schema.json b/output/schema/schema.json
index 9e994b62af..052765732b 100644
--- a/output/schema/schema.json
+++ b/output/schema/schema.json
@@ -139606,7 +139606,7 @@
         "name": "DeploymentAllocationState",
         "namespace": "ml._types"
       },
-      "specLocation": "ml/_types/TrainedModel.ts#L288-L301"
+      "specLocation": "ml/_types/TrainedModel.ts#L289-L302"
     },
     {
       "kind": "enum",
@@ -139628,7 +139628,7 @@
         "name": "DeploymentAssignmentState",
         "namespace": "ml._types"
       },
-      "specLocation": "ml/_types/TrainedModel.ts#L303-L308"
+      "specLocation": "ml/_types/TrainedModel.ts#L304-L309"
     },
     {
       "kind": "enum",
@@ -139650,7 +139650,7 @@
         "name": "DeploymentState",
         "namespace": "ml._types"
       },
-      "specLocation": "ml/_types/TrainedModel.ts#L273-L286"
+      "specLocation": "ml/_types/TrainedModel.ts#L274-L287"
     },
     {
       "kind": "interface",
@@ -140415,7 +140415,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L216-L230"
+      "specLocation": "ml/_types/TrainedModel.ts#L217-L231"
     },
     {
       "kind": "interface",
@@ -143708,7 +143708,7 @@
         "name": "RoutingState",
         "namespace": "ml._types"
       },
-      "specLocation": "ml/_types/TrainedModel.ts#L350-L371"
+      "specLocation": "ml/_types/TrainedModel.ts#L351-L372"
     },
     {
       "kind": "enum",
@@ -144371,7 +144371,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L232-L239"
+      "specLocation": "ml/_types/TrainedModel.ts#L233-L240"
     },
     {
       "kind": "interface",
@@ -144408,7 +144408,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L241-L246"
+      "specLocation": "ml/_types/TrainedModel.ts#L242-L247"
     },
     {
       "kind": "interface",
@@ -144454,7 +144454,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L248-L255"
+      "specLocation": "ml/_types/TrainedModel.ts#L249-L256"
     },
     {
       "kind": "interface",
@@ -144533,7 +144533,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L402-L417"
+      "specLocation": "ml/_types/TrainedModel.ts#L403-L418"
     },
     {
       "kind": "interface",
@@ -144591,7 +144591,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L373-L391"
+      "specLocation": "ml/_types/TrainedModel.ts#L374-L392"
     },
     {
       "kind": "interface",
@@ -144703,7 +144703,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L315-L348"
+      "specLocation": "ml/_types/TrainedModel.ts#L316-L349"
     },
     {
       "kind": "interface",
@@ -144938,9 +144938,20 @@
               "namespace": "ml._types"
             }
           }
+        },
+        {
+          "name": "prefix_strings",
+          "required": false,
+          "type": {
+            "kind": "instance_of",
+            "type": {
+              "name": "TrainedModelPrefixStrings",
+              "namespace": "ml._types"
+            }
+          }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L165-L199"
+      "specLocation": "ml/_types/TrainedModel.ts#L165-L200"
     },
     {
       "kind": "interface",
@@ -144965,7 +144976,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L201-L204"
+      "specLocation": "ml/_types/TrainedModel.ts#L202-L205"
     },
     {
       "kind": "interface",
@@ -145042,7 +145053,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L206-L214"
+      "specLocation": "ml/_types/TrainedModel.ts#L207-L215"
     },
     {
       "kind": "interface",
@@ -145088,7 +145099,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L393-L400"
+      "specLocation": "ml/_types/TrainedModel.ts#L394-L401"
     },
     {
       "kind": "interface",
@@ -145697,7 +145708,7 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L419-L421"
+      "specLocation": "ml/_types/TrainedModel.ts#L420-L422"
     },
     {
       "kind": "interface",
@@ -145718,7 +145729,41 @@
           }
         }
       ],
-      "specLocation": "ml/_types/TrainedModel.ts#L423-L425"
+      "specLocation": "ml/_types/TrainedModel.ts#L424-L426"
+    },
+    {
+      "kind": "interface",
+      "name": {
+        "name": "TrainedModelPrefixStrings",
+        "namespace": "ml._types"
+      },
+      "properties": [
+        {
+          "description": "String prepended to input at ingest",
+          "name": "ingest",
+          "required": true,
+          "type": {
+            "kind": "instance_of",
+            "type": {
+              "name": "string",
+              "namespace": "_builtins"
+            }
+          }
+        },
+        {
+          "description": "String prepended to input at search",
+          "name": "search",
+          "required": true,
+          "type": {
+            "kind": "instance_of",
+            "type": {
+              "name": "string",
+              "namespace": "_builtins"
+            }
+          }
+        }
+      ],
+      "specLocation": "ml/_types/TrainedModel.ts#L428-L437"
     },
     {
       "kind": "interface",
@@ -145865,7 +145910,7 @@
         "name": "TrainedModelType",
         "namespace": "ml._types"
       },
-      "specLocation": "ml/_types/TrainedModel.ts#L257-L271"
+      "specLocation": "ml/_types/TrainedModel.ts#L258-L272"
     },
     {
       "kind": "enum",
@@ -145881,7 +145926,7 @@
         "name": "TrainingPriority",
         "namespace": "ml._types"
       },
-      "specLocation": "ml/_types/TrainedModel.ts#L310-L313"
+      "specLocation": "ml/_types/TrainedModel.ts#L311-L314"
     },
     {
       "kind": "interface",
diff --git a/output/typescript/types.ts b/output/typescript/types.ts
index 041a210e1e..7bf31b4677 100644
--- a/output/typescript/types.ts
+++ b/output/typescript/types.ts
@@ -13246,6 +13246,7 @@ export interface MlTrainedModelConfig {
   metadata?: MlTrainedModelConfigMetadata
   model_size_bytes?: ByteSize
   location?: MlTrainedModelLocation
+  prefix_strings?: MlTrainedModelPrefixStrings
 }
 
 export interface MlTrainedModelConfigInput {
@@ -13333,6 +13334,11 @@ export interface MlTrainedModelLocationIndex {
   name: IndexName
 }
 
+export interface MlTrainedModelPrefixStrings {
+  ingest: string
+  search: string
+}
+
 export interface MlTrainedModelSizeStats {
   model_size_bytes: ByteSize
   required_native_memory_bytes: integer
diff --git a/specification/ml/_types/TrainedModel.ts b/specification/ml/_types/TrainedModel.ts
index 0cb14c14b1..21262132ff 100644
--- a/specification/ml/_types/TrainedModel.ts
+++ b/specification/ml/_types/TrainedModel.ts
@@ -196,6 +196,7 @@ export class TrainedModelConfig {
   metadata?: TrainedModelConfigMetadata
   model_size_bytes?: ByteSize
   location?: TrainedModelLocation
+  prefix_strings?: TrainedModelPrefixStrings
 }
 
 export class TrainedModelConfigInput {
@@ -423,3 +424,14 @@ export class TrainedModelLocation {
 export class TrainedModelLocationIndex {
   name: IndexName
 }
+
+export class TrainedModelPrefixStrings {
+  /**
+   * String prepended to input at ingest
+   */
+  ingest: string
+  /**
+   * String prepended to input at search
+   */
+  search: string
+}