[9.3] [inference] handle array type without items property (#250350) (#250426)

kibanamachine · pgayvallet · web-flow · commit e7cff86ff661 · 2026-01-26T18:18:04.000+01:00
# Backport This will backport the following commits from `main` to `9.3`: - [[inference] handle array type without items property (#250350)](#250350)  ### Questions ? Please refer to the [Backport tool documentation](https://github.com/sorenlouv/backport)  Co-authored-by: Pierre Gayvallet <pierre.gayvallet@elastic.co>
diff --git a/x-pack/platform/packages/shared/ai-infra/inference-common/src/chat_complete/tool_schema.ts b/x-pack/platform/packages/shared/ai-infra/inference-common/src/chat_complete/tool_schema.ts
@@ -37,7 +37,7 @@ interface ToolSchemaTypeNumber extends ToolSchemaFragmentBase {
 
 interface ToolSchemaTypeArray extends ToolSchemaFragmentBase {
   type: 'array';
-  items: Exclude<ToolSchemaType, ToolSchemaTypeArray>;
+  items?: Exclude<ToolSchemaType, ToolSchemaTypeArray>;
 }
 
 /**
@@ -64,9 +64,10 @@ type FromToolSchemaObject<TToolSchemaObject extends ToolSchemaTypeObject> =
       >
     : never;
 
-type FromToolSchemaArray<TToolSchemaObject extends ToolSchemaTypeArray> = Array<
-  FromToolSchema<TToolSchemaObject['items']>
->;
+type FromToolSchemaArray<TToolSchemaObject extends ToolSchemaTypeArray> =
+  TToolSchemaObject['items'] extends Exclude<ToolSchemaType, ToolSchemaTypeArray>
+    ? Array<FromToolSchema<TToolSchemaObject['items']>>
+    : unknown[];
 
 type FromToolSchemaString<TToolSchemaString extends ToolSchemaTypeString> =
   TToolSchemaString extends { const: string }
diff --git a/x-pack/platform/plugins/shared/inference/server/chat_complete/adapters/bedrock/convert_tools.ts b/x-pack/platform/plugins/shared/inference/server/chat_complete/adapters/bedrock/convert_tools.ts
@@ -94,7 +94,7 @@ export function fixSchemaArrayProperties<T extends ToolSchemaType>(schemaPart: T
       description: schemaPart.description
         ? `${schemaPart.description}. Must be provided as a JSON array`
         : 'Must be provided as a JSON array',
-      items: fixSchemaArrayProperties(schemaPart.items),
+      items: schemaPart.items ? fixSchemaArrayProperties(schemaPart.items) : {},
     };
   }
 
diff --git a/x-pack/platform/plugins/shared/inference/server/chat_complete/adapters/gemini/gemini_adapter.ts b/x-pack/platform/plugins/shared/inference/server/chat_complete/adapters/gemini/gemini_adapter.ts
@@ -119,7 +119,8 @@ function toolSchemaToGemini({ schema }: { schema: ToolSchema }): Gemini.Function
         return {
           type: Gemini.SchemaType.ARRAY,
           description: def.description,
-          items: convertSchemaType({ def: def.items }),
+          // @ts-expect-error - items is optional (empty object means any)
+          items: def.items ? convertSchemaType({ def: def.items }) : {},
         };
       case 'object':
         return {
diff --git a/x-pack/platform/plugins/shared/inference/server/chat_complete/adapters/openai/to_openai.ts b/x-pack/platform/plugins/shared/inference/server/chat_complete/adapters/openai/to_openai.ts
@@ -19,20 +19,55 @@ import type { Message, ToolOptions, InferenceConnector } from '@kbn/inference-co
 import { MessageRole } from '@kbn/inference-common';
 import { OpenAiProviderType } from './types';
 
+/**
+ * Recursively processes a schema to ensure all array types have an `items` property.
+ * OpenAI requires `items` to be present for array types.
+ */
+function ensureArrayItems(schema: Record<string, unknown>): Record<string, unknown> {
+  if (typeof schema !== 'object' || schema === null) {
+    return schema;
+  }
+
+  const result = { ...schema };
+
+  if (result.type === 'array' && !('items' in result)) {
+    result.items = {};
+  }
+
+  if (result.items && typeof result.items === 'object') {
+    result.items = ensureArrayItems(result.items as Record<string, unknown>);
+  }
+
+  if (result.properties && typeof result.properties === 'object') {
+    const properties = result.properties as Record<string, unknown>;
+    result.properties = Object.fromEntries(
+      Object.entries(properties).map(([key, value]) => [
+        key,
+        ensureArrayItems(value as Record<string, unknown>),
+      ])
+    );
+  }
+
+  return result;
+}
+
 export function toolsToOpenAI(
   tools: ToolOptions['tools']
 ): OpenAI.ChatCompletionCreateParams['tools'] {
   return tools
     ? Object.entries(tools).map(([toolName, { description, schema }]) => {
+        const parameters = schema ?? {
+          type: 'object' as const,
+          properties: {},
+        };
         return {
           type: 'function',
           function: {
             name: toolName,
             description,
-            parameters: (schema ?? {
-              type: 'object' as const,
-              properties: {},
-            }) as unknown as Record<string, unknown>,
+            parameters: ensureArrayItems(
+              parameters as unknown as Record<string, unknown>
+            ) as unknown as Record<string, unknown>,
           },
         };
       })

Original file line number	Diff line number	Diff line change
`@@ -94,7 +94,7 @@ export function fixSchemaArrayProperties<T extends ToolSchemaType>(schemaPart: T`
`94`	`94`	`description: schemaPart.description`
`95`	`95`	? `${schemaPart.description}. Must be provided as a JSON array`
`96`	`96`	`: 'Must be provided as a JSON array',`
`97`		`- items: fixSchemaArrayProperties(schemaPart.items),`
	`97`	`+ items: schemaPart.items ? fixSchemaArrayProperties(schemaPart.items) : {},`
`98`	`98`	`};`
`99`	`99`	`}`
`100`	`100`