Introduction

We’re currently running a beta for Blocks, an upcoming feature from Vapi.ai aimed at improving bot conversations. The problem we’ve noticed is that single LLM prompts are prone to hallucinations, unreliable tool calls, and can’t handle many-step complex instructions.

By breaking the conversation into smaller, more manageable prompts, we can guarantee the bot will do this, then that, or if this happens, then that happens. It’s like having a checklist for conversations — less room for error, more room for getting things right.

Here’s an example: For food ordering, this is what a prompt would look like.

There are three core types of Blocks: Conversation, Tool-call, and Workflow. Each type serves a different role in shaping how your assistant engages with users.

Advanced Concepts