June 25, 2025

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 and WorkflowGoogleModel objects. Control payload structure for advanced integrations and expand your model choices beyond OpenAI.

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 field. Select between Server-Sent Events (sse) or Streamable HTTP (shttp) protocols for tool communication.

Support Ticket Submission via API

**Create support tickets directly through Vapi ** using the new /support/ticket endpoint, simplifying how you request assistance.

Multilingual LMNT Voice Support: The LMNTVoice and FallbackLMNTVoice objects now support a language property (ISO 639-1 or auto) for selecting or auto-detecting spoken language in synthesized voices.
Assistant Overrides in Chats: The assistantOverrides property is now available in Chat, CreateChatDTO, and OpenAIResponsesRequest, allowing you to dynamically override assistant settings and template variables per chat session.
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.
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.

Breaking Change: The 'aws-sts' type is no longer supported in OAuth2AuthenticationPlan. If you’re currently using this type in your OAuth2 authentication configurations, you’ll need to update it to avoid errors.