Chat & Streaming

This section shows core APIs: chat_completion, streaming variants, cancellation, batch, quick helpers, and model listing. Always verify against the crate version on docs.rs.

Basic Chat Completion

use ai_lib::{AiClient, Provider, ChatCompletionRequest, Message, Role};
use ai_lib::types::common::Content;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
  let client = AiClient::new(Provider::OpenAI)?;
  let req = ChatCompletionRequest::new(
    "gpt-4o".to_string(),
    vec![Message { role: Role::User, content: Content::Text("Summarize Rust ownership succinctly.".to_string()), function_call: None }]
  );
  let resp = client.chat_completion(req).await?;
  if let Some(first) = resp.choices.first() {
    println!("Answer: {}", first.message.content.as_text());
  }
  Ok(())
}

Streaming Tokens

Method assumed: chat_completion_stream(request) returning an async stream of Result<ChatCompletionChunk, AiLibError>.

use ai_lib::{AiClient, Provider, ChatCompletionRequest, Message, Role};
use ai_lib::types::common::Content;
use futures_util::StreamExt; // if using futures stream

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
  let client = AiClient::new(Provider::Groq)?;
  let req = ChatCompletionRequest::new(
    "llama3-8b-8192".to_string(),
    vec![Message { role: Role::User, content: Content::Text("Stream a haiku about concurrency.".to_string()), function_call: None }]
  );
  let mut stream = client.chat_completion_stream(req).await?;
  while let Some(chunk) = stream.next().await {
    match chunk {
      Ok(c) => {
        if let Some(choice) = c.choices.first() {
            if let Some(content) = &choice.delta.content {
                print!("{}", content);
            }
        }
      }
      Err(e) => { eprintln!("stream error: {e}"); break; }
    }
  }
  Ok(())
}

Streaming + Cancellation

Assumed helper: chat_completion_stream_with_cancel(req)(impl Stream, CancelHandle).

use ai_lib::{AiClient, Provider, ChatCompletionRequest, Message, Role};
use ai_lib::types::common::Content;
use futures_util::StreamExt;
use tokio::time::{sleep, Duration};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
  let client = AiClient::new(Provider::OpenAI)?;
  let req = ChatCompletionRequest::new(
    "gpt-4o".into(),
    vec![Message { role: Role::User, content: Content::Text("Explain borrow checker slowly.".into()), function_call: None }]
  );
  let (mut stream, handle) = client.chat_completion_stream_with_cancel(req).await?;
  tokio::select! {
    _ = async {
      while let Some(chunk) = stream.next().await {
        if let Ok(c) = chunk { /* print!("{}", c.delta_text()); */ }
      }
    } => {},
    _ = sleep(Duration::from_millis(400)) => {
      handle.cancel();
      eprintln!("Cancelled after 400ms");
    }
  }
  Ok(())
}

Batch Requests

Two patterns (names assumed):

  1. chat_completion_batch(Vec<ChatCompletionRequest>) – fire concurrently, return Vec of results.
  2. chat_completion_batch_smart – may apply internal heuristics/routing.
use ai_lib::{AiClient, Provider, ChatCompletionRequest, Message, Role};
use ai_lib::types::common::Content;

fn prompt(p: &str) -> ChatCompletionRequest {
  ChatCompletionRequest::new(
    "gpt-4o".into(),
    vec![Message { role: Role::User, content: Content::Text(p.into()), function_call: None }]
  )
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
  let client = AiClient::new(Provider::OpenAI)?;
  let batch = vec![prompt("Define RAII"), prompt("One sentence on lifetimes"), prompt("Explain Send vs Sync")];
  let results = client.chat_completion_batch(batch).await?;
  for (i, r) in results.iter().enumerate() {
    if let Some(c) = r.choices.first() { /* println!("{}: {}", i, c.message_text()); */ }
  }
  Ok(())
}

If a smarter variant exists:

// let results = client.chat_completion_batch_smart(batch).await?;

Quick Helpers

Some crates expose ergonomic shortcuts like quick_chat_text(model, prompt) returning a String.

// let text = client.quick_chat_text("gpt-4o", "What is ownership?" ).await?;
// println!("{text}");

List Models

let models = client.list_models().await?;
for model in models { 
    println!("{}", model); 
}

Notes

Tips:

  • Check docs.rs for any renames (e.g. chat vs chat_completion).
  • Collect streaming deltas into a String if you need the final answer.
  • Batch + streaming together? Launch multiple chat_completion_stream tasks and aggregate.
  • More patterns: Advanced Examples
Build: 3de64ed · 2025-09-09T12:50:59.531Z · v0.21