cognis-core

The foundation crate for Cognis v2, providing the core traits and primitives for building composable AI workflows.

Purpose

cognis-core defines the typed Runnable<I, O> trait, which is the building block of all operations in Cognis. It also provides the essential data structures for chat messages, prompts, output parsing, and functional composition.

Key Features

• Runnable Trait: A standardized interface for any unit of work that can be invoked, batched, or streamed.
• Composition: Primitives like pipe, Parallel, and Branch to build complex chains from simple runnables.
• Messages: Typed chat messages (SystemMessage, HumanMessage, AiMessage, ToolMessage) with support for multi-modal content.
• Prompts: Template systems for generating formatted strings or message sequences.
• Output Parsers: Tools to transform raw LLM output into structured data (JSON, XML, lists, etc.).
• Wrappers: Higher-order runnables for Retry, Fallback, Timeout, and Cache.

Usage

Add this to your Cargo.toml:

[dependencies]
cognis-core = "0.1.0"

Basic Example: Defining and Piping Runnables

use cognis_core::prelude::*;
use async_trait::async_trait;

struct Doubler;

#[async_trait]
impl Runnable<u32, u32> for Doubler {
    async fn invoke(&self, input: u32, _: RunnableConfig) -> Result<u32> {
        Ok(input * 2)
    }
}

#[tokio::main]
async fn main() -> Result<()> {
    let chain = pipe(Doubler, lambda(|x: u32| async move { Ok(x + 1) }));
    
    let result = chain.invoke(5, RunnableConfig::default()).await?;
    assert_eq!(result, 11); // (5 * 2) + 1
    Ok(())
}