A very simple zero-dependency Typescript library that makes LLM prompts slightly easier to work with.

You probably don't need this library (or any library) to build prompts!

JavaScript template literals are great for this.

This library helps with just two small annoyances.

npm install llm-message-utils

Allows you to indent prompts in your code for readability, while automatically trimming whitespace.

Just add the trim tagged template literal, and it will remove:

• any leading or trailing whitespace from each line
• any empty leading or trailing lines

Other empty lines will be preserved.

Usage:

import { trim } from "llm-message-utils";

const system = trim`
    You are a helpful assistant.
    This line looks indented in code, but the value won't be.
    The prompt starts/ends with empty lines, which will also be removed.
`

It's common to build a messages array like this:

const country = "France";
const messages = [
    {
        role: "system",
        content: "You are a helpful assistant"
    },
    {
        role: "user",
        content: `What's the capital of ${country}?"
    },
    {
        role: "assistant",
        content: "The capital of France is Paris"
    }
]

We provide 3 additional tagged template literals as syntactic sugar.

Usage:

import { systemRole, userRole, assistantRole } from "llm-message-utils";

const country = "France";
const messages = [
    systemRole`
        You are a helpful assistant
    `,
    userRole`
        What's the capital of ${country}?
    `,
    assistantRole`
        The capital of France is Paris
    `
]

These create the message objects with a given role, and trim strings (as above) to allow you to indent however you like for readability.