ollama/examples/typescript-simplechat/readme.md

Simple Chat Example

The chat endpoint is one of two ways to generate text from an LLM with Ollama. At a high level you provide the endpoint an array of message objects with a role and content specified. Then with each output and prompt, you add more messages, which builds up the history.

Run the Example

There are a few ways to run this, just like any Typescript code:

1. Compile with tsc and then run it with node client.js.
2. Install tsx and run it with tsx client.ts.
3. Install bun and run it with bun client.ts.

Review the Code

You can see in the chat function that is actually calling the endpoint is simply done with:

const body = {
  model: model,
  messages: messages
}

const response = await fetch("http://localhost:11434/api/chat", {
  method: "POST",
  body: JSON.stringify(body)
})

With the generate endpoint, you need to provide a prompt. But with chat, you provide messages. And the resulting stream of responses includes a message object with a content field.

The final JSON object doesn't provide the full content, so you will need to build the content yourself. In this example, chat takes the full array of messages and outputs the resulting message from this call of the chat endpoint.

In the askQuestion function, we collect user_input and add it as a message to our messages and that is passed to the chat function. When the LLM is done responding the output is added as another message to the messages array.

At the end, you will see a printout of all the messages.

Next Steps

In this example, all generations are kept. You might want to experiment with summarizing everything older than 10 conversations to enable longer history with less context being used.