At the core of llm-ui is useLLMOutput. This hook takes a single chat response from an LLM and breaks it into blocks.

Blocks

useLLMOutput takes blocks and fallbackBlock as parameters.

• blocks is an array of block configurations that useLLMOutput attempts to match against the LLM output.
• fallbackBlock is used for parts of the chat response when no other block matches.

Example

Language model markdown output:

## Python

```python
print('Hello llm-ui!')
```

## Typescript

```typescript
console.log('Hello llm-ui!');
```

If we pass the following parameters to useLLMOutput:

• blocks: [codeBlock] which matches code blocks starting with ```.
• fallbackBlock: markdownBlock which assumes anything else is markdown .

useLLMOutput will break the chat response into code and markdown blocks.

llm-ui breaks the example into blocks:

Throtting

useLLMOutput also takes throttle as an argument. This function allows useLLMOutput to lag behind the actual LLM output.

Here is an example of llm-ui’s throttling in action:

# H1
Hi Docs

```typescript
console.log('hello')
```

# H1
Hi Docs

```typescript
console.log('hello')
```

console.log('hello')

console.log('hello')

The disadvantage of throttling is that the llm output is delayed in reaching the user.

The benefits of throttling:

• llm-ui can smooth out pauses in the LLM’s streamed output.
• Blocks can hide ‘non-user’ characters from user (e.g. ## in a markdown header).