> For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://poly-ai.ferndocs.com/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://poly-ai.ferndocs.com/_mcp/server. # 4.2026 > April 2026 release notes. The **April 2026** PolyAI Agent Studio release introduces first-class multi-language support – configure multilingual agents entirely from the UI, manage translations in a dedicated page, connect external tools with MCP integrations, and script agent configuration through the new Agents API. Expand the items below for details: #### Multi-language support ![source-hub-file-preview](/_fern-files/_img/09aa5097af47a7fd59d8a84616007340ba84a78a58e2e4b8c7663f43ec67935f.webp) Build a single agent that handles multiple languages – no separate projects, no manual `start_function` workarounds. The new **Multi-language** settings page lets you configure everything from the UI. **What's new:** * **Add languages in the UI** – go to **Behavior** and add up to 10 additional languages with a couple of clicks. * **Per-language voices** – assign a dedicated Agent voice and Disclaimer voice for each language under **Voice > Settings**, with multi-voice support per language. The agent switches voice automatically when the conversation language changes. * **Test in any language** – a new language dropdown in Agent Chat lets you start conversations in a specific language to verify behavior before going live. * **Conditional content tags** – wrap language-specific content in `` / `` tags to serve the right version from a single prompt. * **Test in any language** – a new language dropdown in Agent Chat lets you start conversations in a specific language to verify behavior before going live. * **Language metadata** – see which language was used for each conversation in Conversation Review (list and detail), and manage language-tagged audio in Audio Management. See [Multi-language](/agent-studio/behavior/language/multi-language) for full setup instructions. #### Translations ![source-hub-file-preview](/_fern-files/_img/b99a87b5de80d77d488c0455f630740c6fe7de5ffc86c15dd4a971621af67732.webp) Fine-tune how your agent speaks in every language. The new **Translations** page under **Voice > Advanced** gives you a central place to manage auto-translated content and override anything that doesn't sound right. **What's new:** * **Translation cards** – each card holds a piece of content (like a greeting or confirmation message) with versions for every configured language. * **Automatic translation** – when you save a card, all configured languages are translated instantly. Cards that haven't been manually reviewed are marked as "Auto Translated". * **Manual overrides** – edit any translation to fix awkward phrasing, adjust formality, or handle idioms that don't carry over. Overridden entries are marked as "Manually Translated". * **Insert anywhere** – reference translation cards via the action menu in greetings, disclaimers, behavior rules, prompts, delay control responses, and SMS templates. * **Access in functions** – use `conv.translations.your_key` to pull the right translation programmatically for hard-coded utterances. See [Translations](/agent-studio/behavior/language/translations) for setup instructions. #### Agents API Script agent configuration and deployment through a new public REST API. The **Agents API** covers the same surface as Agent Studio's build pipeline — create agents, edit behavior, manage the knowledge base, configure variants, and promote deployments — all from code. **What's new:** * **Full CRUD for agent configuration** – create, update, duplicate, and delete agents; read and update behavior rules on any branch. * **Knowledge base management** – list, create, update, and delete knowledge base topics programmatically, making bulk migrations and CMS sync straightforward. * **Variants and attributes** – sync multi-site variants from a source of truth (locations database, CRM) instead of editing them by hand. * **Deployment pipeline** – publish drafts to Sandbox, promote through Pre-release to Live, and roll back from CI. * **Telephony plumbing** – import phone numbers, reassign them to different connectors, and look up which connector serves a given number. * **Branches and real-time configs** – manage branches and real-time configuration values alongside the rest of the agent. See the [Agents API reference](/api-reference/build-deploy/agents-api/overview) for the full endpoint list. #### MCP integrations ![source-hub-file-preview](/_fern-files/_img/2dc2dec349a4e07ceb52e72e58938a573b789721a3aa7ac6f6259f2c0929702f.webp) Agent Studio now supports [Model Context Protocol](https://modelcontextprotocol.io/) (MCP) integrations, letting you connect external tool servers to your agent directly from the UI. **What's new:** * A dedicated **MCP** tab is now available under **Integrations**. * Add an MCP server by providing a URL, authentication details (Header, Query parameter, or OAuth), and an optional timeout. * Agent Studio **auto-discovers** the tools available on the connected server and displays them in a configuration panel. * **Toggle individual tools** on or off to control which functions are exposed to the agent, helping manage context window usage. * Supports **Header**, **Query parameter**, and **OAuth** authentication methods using secrets from the Secrets Vault. > **Note** > > Projects that previously configured MCP through experimental config will continue to work – the old MCP tab is hidden once the feature is enabled, but existing servers keep running in the background. The old config only stops being used if you add a new MCP server through the new UI. See [MCP integrations](/integrations/mcp/mcp-integrations) for setup instructions.