Add changelog for 2025-06-20

[quantstruct-bot]

Description

New Campaigns APIs and Assistant Improvements

**Create, retrieve, and manage campaigns** using the new [`/campaign` endpoints](https://docs.vapi.ai/api-reference/calls/list#:~:text=Campaign). Build automated call campaigns with specified customers and schedules. **General Availability**: [`Assistant.modelOutputInMessagesEnabled`](https://api.vapi.ai/api#:~:text=SessionPaginatedResponse-,Assistant,-AssistantPaginatedResponse) is now generally available without beta limitations. You can decide whether to use the model's output in conversation history instead of the assistant's speech transcription.

1. Simplified Assistant Property Structure: Properties like serverMessages, clientMessages, and serverUrl have been moved under Assistant.monitorPlan. This reorganization simplifies how you configure monitoring for your assistants.

2. Node-Level Overrides for Model and Voice: In Conversation Node, properties like model, voice, and transcriber now explicitly override the workflow's settings. This allows you to customize these settings for individual nodes within a workflow for greater control.

3. Enhanced Credential Configuration in Assistants: Assistants now support credentials and credentialIds, similar to workflows. This allows you to specify dynamic credentials specifically for assistant calls, enhancing security and flexibility.

4. New Models Available in ConversationNode: You can now use Google Models and Custom Models in conversation nodes. This expands the range of language models that can be integrated into conversation nodes.

 ## Testing Steps

• Run the app locally using fern docs dev or navigate to preview deployment
• Ensure that the changed pages and code snippets work

[github-actions]

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