Quickstart

Install

# Cargo.toml
[dependencies]
minillmlib = "0.3"
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.
    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(())
}

That is the 80% case. Swapping the provider is a one-line change and nothing else moves:

#![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::claude_subscription("claude-haiku-4-5");         // your Pro/Max plan, no API key
GeneratorInfo::custom("my", "http://localhost:8000/v1", "m");   // your own OpenAI-compatible server
}

See Providers for what each does, and Custom Providers for connecting your own server.

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>, an alias for Result<T, MiniLLMError>. The library fails loudly: an auth/validation error, a malformed response, or an exhausted retry surface as a typed MiniLLMError, never a silent empty success.