> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.vapi.ai/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.vapi.ai/_mcp/server.

# Custom Models, Enhanced Campaigns, and MCP Tool Improvements

#### Custom Model Support in Workflows

**Bring your own hosted LLMs and Google Gemini models** to workflows with new [`WorkflowCustomModel`](https://api.vapi.ai/api#:~:text=WorkflowCustomModel) and [`WorkflowGoogleModel`](https://api.vapi.ai/api#:~:text=WorkflowGoogleModel) objects. Control payload structure for advanced integrations and expand your model choices beyond OpenAI.

![](/_fern-img/71e3b276a8e8095a511aa350ac543d273fa7acfd7a8d910554008f4bd7e00a48.webp)

#### Enhanced Campaign Analytics

**Gain deeper insight into campaign performance** with new call counters including `callsCounterQueued`, `callsCounterScheduled`, `callsCounterInProgress`, and `callsCounterEndedVoicemail` for comprehensive campaign tracking.

#### MCP Tool Protocols and Metadata

**Flexible tool integrations** with new [`McpToolMetadata`](https://api.vapi.ai/api#:~:text=McpToolMetadata) field. Select between Server-Sent Events (`sse`) or Streamable HTTP (`shttp`) protocols for tool communication.

#### [Support Ticket Submission via API](https://api.vapi.ai/api#:~:text=SupportTicket)

\*\*Create support tickets directly through Vapi \*\* using the new [`/support/ticket`](https://api.vapi.ai/api#:~:text=SupportTicket) endpoint, simplifying how you request assistance.

1. **Multilingual LMNT Voice Support**: The [`LMNTVoice`](https://api.vapi.ai/api#:~:text=LMNTVoice) and [`FallbackLMNTVoice`](https://api.vapi.ai/api#:~:text=FallbackLMNTVoice) objects now support a `language` property (ISO 639-1 or `auto`) for selecting or auto-detecting spoken language in synthesized voices.

2. **Assistant Overrides in Chats**: The `assistantOverrides` property is now available in [`Chat`](https://api.vapi.ai/api#:~:text=Chat), [`CreateChatDTO`](https://api.vapi.ai/api#:~:text=CreateChatDTO), and [`OpenAIResponsesRequest`](https://api.vapi.ai/api#:~:text=OpenAIResponsesRequest), allowing you to dynamically override assistant settings and template variables per chat session.

3. **New API Endpoints and Objects**: Added `POST /workflow/generate` endpoint for workflow generation with tool IDs, plus new objects including `GenerateWorkflowDTO` and enhanced `CreateMcpToolDTO`/`UpdateMcpToolDTO` with metadata support.

4. **Include Messages in Server Response from Transfer Requests**: When transferring calls, you can now include a `message` to communicate with users during the process with [`ServerMessageResponse.message.message`](https://api.vapi.ai/api#:~:text=ServerMessageResponse).

> **Warning**
>
> **Breaking Change**: The `'aws-sts'` type is no longer supported in [`OAuth2AuthenticationPlan`](https://api.vapi.ai/api#:~:text=OAuth2AuthenticationPlan). If you're currently using this type in your OAuth2 authentication configurations, you'll need to update it to avoid errors.