Knowledge Base Full Prompt – Character / Token Limits?

Hello HeyGen team,

I’m working on an educational use case using Interactive Avatars, with the goal of integrating a structured didactic program composed of multiple modules into the Knowledge Base.

I understand that LiveAvatar API tasks have a limit of around 1,000 characters and that the Knowledge Base is structured into Persona, Instructions, and Knowledge sections. However, I haven’t been able to find clear documentation regarding the maximum character or token limits for the Knowledge Base Full Prompt fields.

In particular, I would like to understand whether these limits apply individually to each section or to the Knowledge Base as a whole, and whether there are any recommended best practices for structuring and managing a large educational curriculum within these constraints.

Could you please confirm the exact limits and provide guidance on how to best structure prompts when the objective is to deliver a complete educational program through an Interactive Avatar?

Thank you in advance for your support.