fix(provider/openai): remove redundant name from custom tool args

.changeset/small-buses-help.md

@@ -0,0 +1,75 @@
+---
+'@ai-sdk/provider-utils': major
+'@ai-sdk/openai': major
+---
+
+### `@ai-sdk/openai`: remove redundant `name` argument from `openai.tools.customTool()`
+
+`openai.tools.customTool()` no longer accepts a `name` field. the tool name is now derived from the sdk tool key (the object key in the `tools` object).
+
+migration: remove the `name` property from `customTool()` calls. the object key is now used as the tool name sent to the openai api.
+
+before:
+
+```ts
+tools: {
+  write_sql: openai.tools.customTool({
+    name: 'write_sql',
+    description: '...',
+  }),
+}
+```
+
+after:
+
+```ts
+tools: {
+  write_sql: openai.tools.customTool({
+    description: '...',
+  }),
+}
+```
+
+### `@ai-sdk/provider-utils`: `createToolNameMapping()` no longer accepts the `resolveProviderToolName` parameter
+
+before: tool name can be set dynamically
+
+```ts
+const toolNameMapping = createToolNameMapping({
+  tools,
+  providerToolNames: {
+    'openai.code_interpreter': 'code_interpreter',
+    'openai.file_search': 'file_search',
+    'openai.image_generation': 'image_generation',
+    'openai.local_shell': 'local_shell',
+    'openai.shell': 'shell',
+    'openai.web_search': 'web_search',
+    'openai.web_search_preview': 'web_search_preview',
+    'openai.mcp': 'mcp',
+    'openai.apply_patch': 'apply_patch',
+  },
+  resolveProviderToolName: tool =>
+    tool.id === 'openai.custom'
+      ? (tool.args as { name?: string }).name
+      : undefined,
+});
+```
+
+after: tool name is static based on `tools` keys
+
+```
+const toolNameMapping = createToolNameMapping({
+  tools,
+  providerToolNames: {
+    'openai.code_interpreter': 'code_interpreter',
+    'openai.file_search': 'file_search',
+    'openai.image_generation': 'image_generation',
+    'openai.local_shell': 'local_shell',
+    'openai.shell': 'shell',
+    'openai.web_search': 'web_search',
+    'openai.web_search_preview': 'web_search_preview',
+    'openai.mcp': 'mcp',
+    'openai.apply_patch': 'apply_patch',
+  }
+});
+```

content/providers/01-ai-sdk-providers/03-openai.mdx

@@ -1114,7 +1114,6 @@ const result = await generateText({
   model: openai.responses('gpt-5.2-codex'),
   tools: {
     write_sql: openai.tools.customTool({
-      name: 'write_sql',
       description: 'Write a SQL SELECT query to answer the user question.',
       format: {
         type: 'grammar',
@@ -1144,7 +1143,6 @@ const result = streamText({
   model: openai.responses('gpt-5.2-codex'),
   tools: {
     write_sql: openai.tools.customTool({
-      name: 'write_sql',
       description: 'Write a SQL SELECT query to answer the user question.',
       format: {
         type: 'grammar',
@@ -1167,7 +1165,6 @@ for await (const chunk of result.fullStream) {
 
 The custom tool can be configured with:
 
-- **name** _string_ (required) - The name of the custom tool. Used to identify the tool in tool calls.
 - **description** _string_ (optional) - A description of what the tool does, to help the model understand when to use it.
 - **format** _object_ (optional) - The output format constraint. Omit for unconstrained text output.
   - **type** _'grammar' | 'text'_ - The format type. Use `'grammar'` for constrained output or `'text'` for explicit unconstrained text.

examples/ai-functions/src/generate-text/openai/responses-custom-tool-multi-turn.ts

@@ -8,7 +8,6 @@ run(async () => {
     model: openai.responses('gpt-5.2-codex'),
     tools: {
       write_sql: openai.tools.customTool({
-        name: 'write_sql',
         description: 'Write a SQL SELECT query to answer the user question.',
         format: {
           type: 'grammar',

examples/ai-functions/src/generate-text/openai/responses-custom-tool.ts

@@ -8,7 +8,6 @@ run(async () => {
     model: openai.responses('gpt-5.2-codex'),
     tools: {
       write_sql: openai.tools.customTool({
-        name: 'write_sql',
         description: 'Write a SQL SELECT query to answer the user question.',
         format: {
           type: 'grammar',

examples/ai-functions/src/stream-text/openai/responses-custom-tool-multi-turn.ts

@@ -7,7 +7,6 @@ run(async () => {
     model: openai.responses('gpt-5.2-codex'),
     tools: {
       write_sql: openai.tools.customTool({
-        name: 'write_sql',
         description: 'Write a SQL SELECT query to answer the user question.',
         format: {
           type: 'grammar',

examples/ai-functions/src/stream-text/openai/responses-custom-tool.ts

@@ -7,7 +7,6 @@ run(async () => {
     model: openai.responses('gpt-5.2-codex'),
     tools: {
       write_sql: openai.tools.customTool({
-        name: 'write_sql',
         description: 'Write a SQL SELECT query to answer the user question.',
         format: {
           type: 'grammar',

packages/openai/src/openai-tools.ts

@@ -25,7 +25,6 @@ export const openaiTools = {
    * Lark syntax). The model returns a `custom_tool_call` output item whose
    * `input` field is a string matching the specified grammar.
    *
-   * @param name - The name of the custom tool.
    * @param description - An optional description of the tool.
    * @param format - The output format constraint (grammar type, syntax, and definition).
    */

packages/openai/src/responses/convert-to-openai-responses-input.test.ts

@@ -3942,46 +3942,6 @@ describe('convertToOpenAIResponsesInput', () => {
       `);
     });
 
-    it('should convert aliased tool name to provider custom tool name', async () => {
-      const result = await convertToOpenAIResponsesInput({
-        toolNameMapping: {
-          toProviderToolName: name =>
-            name === 'alias_name' ? 'write_sql' : name,
-          toCustomToolName: name =>
-            name === 'write_sql' ? 'alias_name' : name,
-        },
-        prompt: [
-          {
-            role: 'assistant',
-            content: [
-              {
-                type: 'tool-call',
-                toolCallId: 'call_custom_004',
-                toolName: 'alias_name',
-                input: 'SELECT 1',
-              },
-            ],
-          },
-        ],
-        systemMessageMode: 'system',
-        providerOptionsName: 'openai',
-        store: true,
-        customProviderToolNames,
-      });
-
-      expect(result.input).toMatchInlineSnapshot(`
-        [
-          {
-            "call_id": "call_custom_004",
-            "id": undefined,
-            "input": "SELECT 1",
-            "name": "write_sql",
-            "type": "custom_tool_call",
-          },
-        ]
-      `);
-    });
-
     it('should convert custom tool result content output', async () => {
       const result = await convertToOpenAIResponsesInput({
         toolNameMapping: testToolNameMapping,

packages/openai/src/responses/openai-responses-language-model.test.ts

@@ -4098,7 +4098,6 @@ describe('OpenAIResponsesLanguageModel', () => {
               id: 'openai.custom',
               name: 'write_sql',
               args: {
-                name: 'write_sql',
                 description:
                   'Write a SQL SELECT query to answer the user question.',
                 format: {
@@ -4169,45 +4168,6 @@ describe('OpenAIResponsesLanguageModel', () => {
           }
         `);
       });
-
-      it('should map aliased custom tool names in toolChoice and response parsing', async () => {
-        prepareJsonFixtureResponse('openai-custom-tool.1');
-
-        const aliasedResult = await createModel('gpt-5.2-codex').doGenerate({
-          prompt: TEST_PROMPT,
-          toolChoice: { type: 'tool', toolName: 'alias_name' },
-          tools: [
-            {
-              type: 'provider',
-              id: 'openai.custom',
-              name: 'alias_name',
-              args: {
-                name: 'write_sql',
-                description:
-                  'Write a SQL SELECT query to answer the user question.',
-                format: {
-                  type: 'grammar',
-                  syntax: 'regex',
-                  definition: 'SELECT .+',
-                },
-              },
-            },
-          ],
-        });
-
-        expect(
-          (await server.calls.at(-1)!.requestBodyJson).tool_choice,
-        ).toStrictEqual({
-          type: 'custom',
-          name: 'write_sql',
-        });
-
-        const toolCall = aliasedResult.content.find(
-          part => part.type === 'tool-call',
-        );
-        expect(toolCall).toBeDefined();
-        expect((toolCall as { toolName: string }).toolName).toBe('alias_name');
-      });
     });
 
     it('should handle computer use tool calls', async () => {
@@ -5766,7 +5726,6 @@ describe('OpenAIResponsesLanguageModel', () => {
               id: 'openai.custom',
               name: 'write_sql',
               args: {
-                name: 'write_sql',
                 description:
                   'Write a SQL SELECT query to answer the user question.',
                 format: {
@@ -5867,47 +5826,6 @@ describe('OpenAIResponsesLanguageModel', () => {
             ]
           `);
       });
-
-      it('should map aliased custom tool names while streaming', async () => {
-        prepareChunksFixtureResponse('openai-custom-tool.1');
-
-        const { stream } = await createModel('gpt-5.2-codex').doStream({
-          tools: [
-            {
-              type: 'provider',
-              id: 'openai.custom',
-              name: 'alias_name',
-              args: {
-                name: 'write_sql',
-                description:
-                  'Write a SQL SELECT query to answer the user question.',
-                format: {
-                  type: 'grammar',
-                  syntax: 'regex',
-                  definition: 'SELECT .+',
-                },
-              },
-            },
-          ],
-          toolChoice: { type: 'tool', toolName: 'alias_name' },
-          prompt: TEST_PROMPT,
-          includeRawChunks: false,
-        });
-
-        expect(
-          (await server.calls.at(-1)!.requestBodyJson).tool_choice,
-        ).toStrictEqual({
-          type: 'custom',
-          name: 'write_sql',
-        });
-
-        const parts = await convertReadableStreamToArray(stream);
-        const streamToolCall = parts.find(part => part.type === 'tool-call');
-        expect(streamToolCall).toBeDefined();
-        expect((streamToolCall as { toolName: string }).toolName).toBe(
-          'alias_name',
-        );
-      });
     });
 
     describe('web search tool', () => {

packages/openai/src/responses/openai-responses-language-model.ts

@@ -199,10 +199,6 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV4 {
         'openai.apply_patch': 'apply_patch',
         'openai.tool_search': 'tool_search',
       },
-      resolveProviderToolName: tool =>
-        tool.id === 'openai.custom'
-          ? (tool.args as { name?: string }).name
-          : undefined,
     });
 
     const customProviderToolNames = new Set<string>();