Add changelog for 2025-06-25

Author: quantstruct-bot

fern/changelog/2025-06-25-1.mdx

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+# Custom Models, Enhanced Campaigns, and MCP Tool Improvements
+
+<Card title="Custom Model Support in Workflows" icon="brain">
+  **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.
+<Frame caption="Google Model Configuration">
+    <img src="../static/images/changelog/gemini-2.5-pro.png" />
+</Frame>
+</Card>
+
+<Card title="Enhanced Campaign Analytics" icon="chart-line">
+  **Gain deeper insight into campaign performance** with new call counters including `callsCounterQueued`, `callsCounterScheduled`, `callsCounterInProgress`, and `callsCounterEndedVoicemail` for comprehensive campaign tracking.
+</Card>
+
+<Card title="MCP Tool Protocols and Metadata" icon="tools">
+  **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.
+</Card>
+
+<Card title="Support Ticket Submission via API" icon="ticket" href="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.
+</Card>
+
+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).
+
+5. **Org Concurrency Limit Deprecated**: The `concurrencyLimit` field in [`Org`](https://api.vapi.ai/api#:~:text=Org), [`CreateOrgDTO`](https://api.vapi.ai/api#:~:text=CreateOrgDTO), and [`UpdateOrgDTO`](https://api.vapi.ai/api#:~:text=UpdateOrgDTO) is now marked as deprecated.
+
+<Warning>
+**Breaking Change**: The `codeSwitchingEnabled` property has been removed from Deepgram transcribers. If you're currently using this property in your Deepgram transcriber configurations, you'll need to remove it to avoid errors.
+</Warning>
+
+<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.
+</Warning>