llama-stack-mirror/docs/source/getting_started/index.md

Quick Start

In this guide, we'll through how you can use the Llama Stack client SDK to build a simple RAG agent.

The most critical requirement for running the agent is running inference on the underlying Llama model. Depending on what hardware (GPUs) you have available, you have various options. We will use Ollama for this purpose as it is the easiest to get started with and yet robust.

First, let's set up some environment variables that we will use in the rest of the guide. Note that if you open up a new terminal, you will need to set these again.

export INFERENCE_MODEL="meta-llama/Llama-3.2-3B-Instruct"
# ollama names this model differently, and we must use the ollama name when loading the model
export OLLAMA_INFERENCE_MODEL="llama3.2:3b-instruct-fp16"
export LLAMA_STACK_PORT=5001

1. Start Ollama

ollama run $OLLAMA_INFERENCE_MODEL --keepalive 60m

By default, Ollama keeps the model loaded in memory for 5 minutes which can be too short. We set the --keepalive flag to 60 minutes to ensure the model remains loaded for sometime.

2. Start the Llama Stack server

Llama Stack is based on a client-server architecture. It consists of a server which can be configured very flexibly so you can mix-and-match various providers for its individual API components -- beyond Inference, these include Memory, Agents, Telemetry, Evals and so forth.

To get started quickly, we provide various Docker images for the server component that work with different inference providers out of the box. For this guide, we will use llamastack/distribution-ollama as the Docker image.

docker run -it \
  -p $LLAMA_STACK_PORT:$LLAMA_STACK_PORT \
  -v ~/.llama:/root/.llama \
  llamastack/distribution-ollama \
  --port $LLAMA_STACK_PORT \
  --env INFERENCE_MODEL=$INFERENCE_MODEL \
  --env OLLAMA_URL=http://host.docker.internal:11434

Configuration for this is available at distributions/ollama/run.yaml.

3. Use the Llama Stack client SDK

You can interact with the Llama Stack server using various client SDKs. We will use the Python SDK which you can install using the following command. Note that you must be using Python 3.10 or newer:

pip install llama-stack-client

Let's use the llama-stack-client CLI to check the connectivity to the server.

llama-stack-client configure --endpoint http://localhost:$LLAMA_STACK_PORT
llama-stack-client models list
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━┓
┃ identifier                       ┃ provider_id ┃ provider_resource_id      ┃ metadata ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━┩
│ meta-llama/Llama-3.2-3B-Instruct │ ollama      │ llama3.2:3b-instruct-fp16 │          │
└──────────────────────────────────┴─────────────┴───────────────────────────┴──────────┘

You can test basic Llama inference completion using the CLI too.

llama-stack-client \
  inference chat-completion \
  --message "hello, what model are you?"

Here is a simple example to perform chat completions using Python instead of the CLI.

import os
from llama_stack_client import LlamaStackClient

client = LlamaStackClient(base_url=f"http://localhost:{os.environ['LLAMA_STACK_PORT']}")

# List available models
models = client.models.list()
print(models)

response = client.inference.chat_completion(
    model_id=os.environ["INFERENCE_MODEL"],
    messages=[
        {"role": "system", "content": "You are a helpful assistant."},
        {"role": "user", "content": "Write a haiku about coding"}
    ]
)
print(response.completion_message.content)

4. Your first RAG agent

Here is an example of a simple RAG agent that uses the Llama Stack client SDK.

import asyncio
import os

from llama_stack_client import LlamaStackClient
from llama_stack_client.lib.agents.agent import Agent
from llama_stack_client.lib.agents.event_logger import EventLogger
from llama_stack_client.types import Attachment
from llama_stack_client.types.agent_create_params import AgentConfig


async def run_main():
    urls = ["chat.rst", "llama3.rst", "datasets.rst", "lora_finetune.rst"]
    attachments = [
        Attachment(
            content=f"https://raw.githubusercontent.com/pytorch/torchtune/main/docs/source/tutorials/{url}",
            mime_type="text/plain",
        )
        for i, url in enumerate(urls)
    ]

    client = LlamaStackClient(base_url=f"http://localhost:{os.environ['LLAMA_STACK_PORT']}")

    agent_config = AgentConfig(
        model=os.environ["INFERENCE_MODEL"],
        instructions="You are a helpful assistant",
        tools=[{"type": "memory"}],  # enable Memory aka RAG
        enable_session_persistence=True,
    )

    agent = Agent(client, agent_config)
    session_id = agent.create_session("test-session")
    user_prompts = [
        (
            "I am attaching documentation for Torchtune. Help me answer questions I will ask next.",
            attachments,
        ),
        (
            "What are the top 5 topics that were explained? Only list succinct bullet points.",
            None,
        ),
    ]
    for prompt, attachments in user_prompts:
        response = agent.create_turn(
            messages=[{"role": "user", "content": prompt}],
            attachments=attachments,
            session_id=session_id,
        )
        for log in EventLogger().log(response):
            log.print()


if __name__ == "__main__":
    asyncio.run(run_main())

Next Steps

• Learn more about Llama Stack Concepts
• Learn how to Build Llama Stacks
• See References for more details about the llama CLI and Python SDK
• For example applications and more detailed tutorials, visit our llama-stack-apps repository.