Composable building blocks to build Llama Apps https://llama-stack.readthedocs.io
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Sébastien Han 43c1f39bd6
refactor(env)!: enhanced environment variable substitution (#2490)
# What does this PR do?

This commit significantly improves the environment variable substitution
functionality in Llama Stack configuration files:
* The version field in configuration files has been changed from string
to integer type for better type consistency across build and run
configurations.

* The environment variable substitution system for ${env.FOO:} was fixed
and properly returns an error

* The environment variable substitution system for ${env.FOO+} returns
None instead of an empty strings, it better matches type annotations in
config fields

* The system includes automatic type conversion for boolean, integer,
and float values.

* The error messages have been enhanced to provide clearer guidance when
environment variables are missing, including suggestions for using
default values or conditional syntax.

* Comprehensive documentation has been added to the configuration guide
explaining all supported syntax patterns, best practices, and runtime
override capabilities.

* Multiple provider configurations have been updated to use the new
conditional syntax for optional API keys, making the system more
flexible for different deployment scenarios. The telemetry configuration
has been improved to properly handle optional endpoints with appropriate
validation, ensuring that required endpoints are specified when their
corresponding sinks are enabled.

* There were many instances of ${env.NVIDIA_API_KEY:} that should have
caused the code to fail. However, due to a bug, the distro server was
still being started, and early validation wasn’t triggered. As a result,
failures were likely being handled downstream by the providers. I’ve
maintained similar behavior by using ${env.NVIDIA_API_KEY:+}, though I
believe this is incorrect for many configurations. I’ll leave it to each
provider to correct it as needed.

* Environment variable substitution now uses the same syntax as Bash
parameter expansion.

Signed-off-by: Sébastien Han <seb@redhat.com>
2025-06-26 08:20:08 +05:30
.github chore: do not build on auth ci test (#2505) 2025-06-24 21:08:33 +05:30
docs refactor(env)!: enhanced environment variable substitution (#2490) 2025-06-26 08:20:08 +05:30
llama_stack refactor(env)!: enhanced environment variable substitution (#2490) 2025-06-26 08:20:08 +05:30
rfcs chore: remove straggler references to llama-models (#1345) 2025-03-01 14:26:03 -08:00
scripts chore: bump python supported version to 3.12 (#2475) 2025-06-24 09:22:04 +05:30
tests refactor(env)!: enhanced environment variable substitution (#2490) 2025-06-26 08:20:08 +05:30
.coveragerc chore: exclude test, provider, and template directories from coverage (#2028) 2025-04-25 12:16:57 -07:00
.gitignore feat(ui): add infinite scroll pagination to chat completions/responses logs table (#2466) 2025-06-18 15:28:39 -07:00
.pre-commit-config.yaml chore: bump python supported version to 3.12 (#2475) 2025-06-24 09:22:04 +05:30
.readthedocs.yaml fix: build docs without requirements.txt (#2294) 2025-05-27 16:27:57 -07:00
CHANGELOG.md docs: Add recent releases (#2424) 2025-06-10 08:43:02 +05:30
CODE_OF_CONDUCT.md Initial commit 2024-07-23 08:32:33 -07:00
CONTRIBUTING.md chore: bump python supported version to 3.12 (#2475) 2025-06-24 09:22:04 +05:30
install.sh fix: clarify bash requirement in install flow (#2450) 2025-06-17 13:03:28 +05:30
LICENSE Update LICENSE (#47) 2024-08-29 07:39:50 -07:00
MANIFEST.in chore: remove dependencies.json (#2281) 2025-05-27 10:26:57 -07:00
pyproject.toml chore: remove nested imports (#2515) 2025-06-26 08:01:05 +05:30
README.md fix: clarify bash requirement in install flow (#2450) 2025-06-17 13:03:28 +05:30
requirements.txt chore: upgrade hf hub dependency (#2487) 2025-06-20 15:50:54 -07:00
SECURITY.md Create SECURITY.md 2024-10-08 13:30:40 -04:00
uv.lock chore: bump python supported version to 3.12 (#2475) 2025-06-24 09:22:04 +05:30

Llama Stack

PyPI version PyPI - Downloads License Discord Unit Tests Integration Tests

Quick Start | Documentation | Colab Notebook | Discord

🎉 Llama 4 Support 🎉

We released Version 0.2.0 with support for the Llama 4 herd of models released by Meta.

👋 Click here to see how to run Llama 4 models on Llama Stack


Note you need 8xH100 GPU-host to run these models

pip install -U llama_stack

MODEL="Llama-4-Scout-17B-16E-Instruct"
# get meta url from llama.com
llama model download --source meta --model-id $MODEL --meta-url <META_URL>

# start a llama stack server
INFERENCE_MODEL=meta-llama/$MODEL llama stack build --run --template meta-reference-gpu

# install client to interact with the server
pip install llama-stack-client

CLI

# Run a chat completion
llama-stack-client --endpoint http://localhost:8321 \
inference chat-completion \
--model-id meta-llama/$MODEL \
--message "write a haiku for meta's llama 4 models"

ChatCompletionResponse(
    completion_message=CompletionMessage(content="Whispers in code born\nLlama's gentle, wise heartbeat\nFuture's soft unfold", role='assistant', stop_reason='end_of_turn', tool_calls=[]),
    logprobs=None,
    metrics=[Metric(metric='prompt_tokens', value=21.0, unit=None), Metric(metric='completion_tokens', value=28.0, unit=None), Metric(metric='total_tokens', value=49.0, unit=None)]
)

Python SDK

from llama_stack_client import LlamaStackClient

client = LlamaStackClient(base_url=f"http://localhost:8321")

model_id = "meta-llama/Llama-4-Scout-17B-16E-Instruct"
prompt = "Write a haiku about coding"

print(f"User> {prompt}")
response = client.inference.chat_completion(
    model_id=model_id,
    messages=[
        {"role": "system", "content": "You are a helpful assistant."},
        {"role": "user", "content": prompt},
    ],
)
print(f"Assistant> {response.completion_message.content}")

As more providers start supporting Llama 4, you can use them in Llama Stack as well. We are adding to the list. Stay tuned!

🚀 One-Line Installer 🚀

To try Llama Stack locally, run:

curl -LsSf https://github.com/meta-llama/llama-stack/raw/main/install.sh | bash

Overview

Llama Stack standardizes the core building blocks that simplify AI application development. It codifies best practices across the Llama ecosystem. More specifically, it provides

  • Unified API layer for Inference, RAG, Agents, Tools, Safety, Evals, and Telemetry.
  • Plugin architecture to support the rich ecosystem of different API implementations in various environments, including local development, on-premises, cloud, and mobile.
  • Prepackaged verified distributions which offer a one-stop solution for developers to get started quickly and reliably in any environment.
  • Multiple developer interfaces like CLI and SDKs for Python, Typescript, iOS, and Android.
  • Standalone applications as examples for how to build production-grade AI applications with Llama Stack.
Llama Stack

Llama Stack Benefits

  • Flexible Options: Developers can choose their preferred infrastructure without changing APIs and enjoy flexible deployment choices.
  • Consistent Experience: With its unified APIs, Llama Stack makes it easier to build, test, and deploy AI applications with consistent application behavior.
  • Robust Ecosystem: Llama Stack is already integrated with distribution partners (cloud providers, hardware vendors, and AI-focused companies) that offer tailored infrastructure, software, and services for deploying Llama models.

By reducing friction and complexity, Llama Stack empowers developers to focus on what they do best: building transformative generative AI applications.

API Providers

Here is a list of the various API providers and available distributions that can help developers get started easily with Llama Stack.

API Provider Builder Environments Agents Inference Memory Safety Telemetry Post Training
Meta Reference Single Node
SambaNova Hosted
Cerebras Hosted
Fireworks Hosted
AWS Bedrock Hosted
Together Hosted
Groq Hosted
Ollama Single Node
TGI Hosted and Single Node
NVIDIA NIM Hosted and Single Node
Chroma Single Node
PG Vector Single Node
PyTorch ExecuTorch On-device iOS
vLLM Hosted and Single Node
OpenAI Hosted
Anthropic Hosted
Gemini Hosted
watsonx Hosted
HuggingFace Single Node
TorchTune Single Node
NVIDIA NEMO Hosted

Distributions

A Llama Stack Distribution (or "distro") is a pre-configured bundle of provider implementations for each API component. Distributions make it easy to get started with a specific deployment scenario - you can begin with a local development setup (eg. ollama) and seamlessly transition to production (eg. Fireworks) without changing your application code. Here are some of the distributions we support:

Distribution Llama Stack Docker Start This Distribution
Meta Reference llamastack/distribution-meta-reference-gpu Guide
SambaNova llamastack/distribution-sambanova Guide
Cerebras llamastack/distribution-cerebras Guide
Ollama llamastack/distribution-ollama Guide
TGI llamastack/distribution-tgi Guide
Together llamastack/distribution-together Guide
Fireworks llamastack/distribution-fireworks Guide
vLLM llamastack/distribution-remote-vllm Guide

Documentation

Please checkout our Documentation page for more details.

Llama Stack Client SDKs

Language Client SDK Package
Python llama-stack-client-python PyPI version
Swift llama-stack-client-swift Swift Package Index
Typescript llama-stack-client-typescript NPM version
Kotlin llama-stack-client-kotlin Maven version

Check out our client SDKs for connecting to a Llama Stack server in your preferred language, you can choose from python, typescript, swift, and kotlin programming languages to quickly build your applications.

You can find more example scripts with client SDKs to talk with the Llama Stack server in our llama-stack-apps repo.