feat(ai): SDK 5, tool calling, custom backends [render preview]

[YousefED]

This PR is a major update to BlockNote AI 🔥

Overview

• Updates BlockNote AI to use the Vercel AI SDK 5 (closes The ai-sdk has updated to v5, requesting the compatible AI extension #1952)
• Now uses streamText + tool calling by default instead of Object Generation
• Designed to call your own backend (instead of the old proxy-based setup).
• Leans in more heavily to the updated AI SDK architecture (reusing the Chat and transport concepts)
• PromptBuilders have been redesigned to split the creation of the required data (PromptBuilderInputData and creation / modification of the LLMMessages
• fix: better handling of parallel tool calls

Backend pattern

We've revisited the old solution where BlockNote made direct calls to LLMs from the client using the Vercel AI SDK (or via a proxy).

Instead it's now recommended to send request to your backend. There, you can then invoke your LLM (potentially adding more context, tools, RAG, etc). While a bit more work to set up, this architecture is more inline with the Vercel SDK and unlocks more powerful workflows.

Breaking changes

See the updated docs (TODO) and backend integration guide (TODO) for an overview of the new APIs. The main breaking change is that createAIExtension now accepts a transport that provides the integration with your backend.

We now recommend to use the Vercel AI SDK on your backend. For alternative options, see the backend integration guide. The previous proxy-based approach is still available and explained in the backend guide.

For assistance in upgrading and integration with your pipeline, please reach out to the team.

supersedes #1903 and #1898
closes #1952
closes #1793
closes #1783
closes #1753
closes #1847
closes #1988

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Project	Deployment	Preview	Updated (UTC)
blocknote	Ready	Preview	Sep 25, 2025 1:34pm
blocknote-website	Ready	Preview	Sep 25, 2025 1:34pm