LLMGleam

A Gleam library for interacting with Large Language Model APIs. Currently supports Google’s Gemini and OpenAI’s GPT APIs with a clean, type-safe interface.

Features

• 🔒 Type-safe: Leverages Gleam’s type system for reliable API interactions
• 🌟 Clean API: Fluent builder pattern for constructing requests
• 🔌 Extensible: Designed to support multiple LLM providers
• ⚡ Async: Built on Gleam’s concurrent model

Installation

gleam add llmgleam

Quick Start

import llmgleam
import llmgleam/client
import llmgleam/messages

pub fn main() {
  // Create a client
  let client = llmgleam.new_client(client.Gemini, "your-api-key-here")
  
  // Get completion using the builder pattern
  let result =
    client
    |> client.request()
    |> client.with_message(messages.user("Hello, how are you?"))
    |> client.completion("gemini-2.5-flash")
  
  case result {
    Ok(completion) -> {
      io.println("Response: " <> completion.content)
    }
    Error(error) -> {
      io.println("Error: " <> string.inspect(error))
    }
  }
}

API Reference

Creating a Client

import llmgleam
import llmgleam/client

// For Gemini
let gemini_client = llmgleam.new_client(client.Gemini, "your-gemini-api-key")

// For GPT
let gpt_client = llmgleam.new_client(client.GPT, "your-openai-api-key")

Building Requests

The library uses a fluent builder pattern for constructing requests:

import llmgleam/client
import llmgleam/messages

let completion =
  client
  |> client.request()
  |> client.with_message(messages.user("Hello, how are you?"))
  |> client.with_system_instruction("You are a helpful assistant")
  |> client.completion("gemini-2.5-flash")

Messages

import llmgleam/messages

// Create a user message
let user_msg = messages.user("Hello, how are you?")

// System instructions are added via with_system_instruction

Functions

llmgleam.new_client(provider: Provider, api_key: String) -> Client

Creates a new LLM client for the specified provider.

client.request(client: Client) -> Request

Initializes a new request builder from a client.

client.with_message(request: Request, message: Message) -> Request

Adds a message to the request.

client.with_system_instruction(request: Request, instruction: String) -> Request

Adds a system instruction to the request.

client.completion(request: Request, model: String) -> Result(Completion, CompletionError)

Executes the request and returns a completion.

Supported Providers

Google Gemini

• Provider: client.Gemini
• Authentication: API key via Google AI Studio

OpenAI GPT

• Provider: client.GPT
• Authentication: API key via OpenAI

Example with System Instructions

import llmgleam
import llmgleam/client
import llmgleam/messages

let client = llmgleam.new_client(client.Gemini, "your-api-key")

let completion =
  client
  |> client.request()
  |> client.with_message(messages.user("hello, how are you?"))
  |> client.with_system_instruction("you are a helpful conversationalist")
  |> client.completion("gemini-2.5-flash")

Development

Running Tests

gleam test

For integration tests (requires API keys):

RUN_INTEGRATION_TESTS=1 GEMINI_KEY=your-key GPT_KEY=your-key gleam test

Building

gleam build

Contributing

Contributions are welcome! Areas for improvement:

• [X] Add support for OpenAI GPT models
• [X] Add support for Gemini API
• [ ] Add support for Gemini through vertex.ai
• [ ] Add support for Anthropic Claude
• [ ] Add streaming support
• [ ] Add function calling support
• [ ] Add image/multimodal support

License

This project is licensed under the MIT License - see the LICENSE file for details.