Quickstart

Install

# Cargo.toml
[dependencies]
minillmlib = "0.6"
tokio = { version = "1", features = ["full"] }

One call

use minillmlib::{ChatNode, GeneratorInfo};

#[tokio::main]
async fn main() -> minillmlib::Result<()> {
    // Pick a provider. OpenRouter reads OPENROUTER_API_KEY from the environment
    // (if it is in a .env file, call `minillmlib::init()` first, which loads it).
    let generator = GeneratorInfo::openrouter("google/gemini-2.5-flash-lite");

    // A conversation is a tree; `root` is the system prompt.
    let root = ChatNode::root("You are a helpful assistant. Be brief.");

    // `chat` = add a user message + get the assistant reply (returns the new node).
    let answer = root.chat("Say hello in five words.", &generator).await?;

    println!("{}", answer.message.text().unwrap_or(""));
    Ok(())
}

If you want another provider, change that one line:

#![allow(unused)]
fn main() {
use minillmlib::GeneratorInfo;
GeneratorInfo::openrouter("google/gemini-2.5-flash-lite");      // OPENROUTER_API_KEY
GeneratorInfo::openai("gpt-4o-mini");                           // OPENAI_API_KEY
GeneratorInfo::anthropic("claude-haiku-4-5");                   // ANTHROPIC_API_KEY, native /v1/messages
GeneratorInfo::custom("my", "http://localhost:8000/v1", "m");   // your own OpenAI-compatible server
}

For what each preset does, go and read Providers, and to connect your own server, Custom Providers.

A multi-turn conversation

Each chat returns the assistant node; chain from it to continue the thread.

use minillmlib::{ChatNode, GeneratorInfo};

#[tokio::main]
async fn main() -> minillmlib::Result<()> {
    let gen = GeneratorInfo::openrouter("google/gemini-2.5-flash-lite");
    let root = ChatNode::root("You are a terse assistant.");

    let a1 = root.chat("What's the capital of France?", &gen).await?;
    let a2 = a1.chat("And its population, roughly?", &gen).await?;

    println!("{}", a2.message.text().unwrap_or(""));
    // a2 knows its whole history: a2.thread() is the full root-to-leaf message list.
    Ok(())
}

Errors

Every fallible call returns minillmlib::Result<T>, whose error is a MiniLLMError you can match on: Api { status, message } when the provider refuses, Timeout, and MaxRetriesExceeded once retries you turned on run out. An empty reply counts as a success unless you pass NodeCompletionParameters::new().with_crash_on_empty(true) to complete (see Completion Parameters).