Move the test_context.py under the main tests directory, and fix the code. The problem was that the function captures the initial values of the context variables and then restores those same initial values before each iteration. This means that any modifications made to the context variables during iteration are lost when the next iteration starts. Error was: ``` ====================================================== FAILURES ======================================================= ______________________________________ test_preserve_contexts_across_event_loops ______________________________________ @pytest.mark.asyncio async def test_preserve_contexts_across_event_loops(): """ Test that context variables are preserved across event loop boundaries with nested generators. This simulates the real-world scenario where: 1. A new event loop is created for each streaming request 2. The async generator runs inside that loop 3. There are multiple levels of nested generators 4. Context needs to be preserved across these boundaries """ # Create context variables request_id = ContextVar("request_id", default=None) user_id = ContextVar("user_id", default=None) # Set initial values # Results container to verify values across thread boundaries results = [] # Inner-most generator (level 2) async def inner_generator(): # Should have the context from the outer scope yield (1, request_id.get(), user_id.get()) # Modify one context variable user_id.set("user-modified") # Should reflect the modification yield (2, request_id.get(), user_id.get()) # Middle generator (level 1) async def middle_generator(): inner_gen = inner_generator() # Forward the first yield from inner item = await inner_gen.__anext__() yield item # Forward the second yield from inner item = await inner_gen.__anext__() yield item request_id.set("req-modified") # Add our own yield with both modified variables yield (3, request_id.get(), user_id.get()) # Function to run in a separate thread with a new event loop def run_in_new_loop(): # Create a new event loop for this thread loop = asyncio.new_event_loop() asyncio.set_event_loop(loop) try: # Outer generator (runs in the new loop) async def outer_generator(): request_id.set("req-12345") user_id.set("user-6789") # Wrap the middle generator wrapped_gen = preserve_contexts_async_generator(middle_generator(), [request_id, user_id]) # Process all items from the middle generator async for item in wrapped_gen: # Store results for verification results.append(item) # Run the outer generator in the new loop loop.run_until_complete(outer_generator()) finally: loop.close() # Run the generator chain in a separate thread with a new event loop with ThreadPoolExecutor(max_workers=1) as executor: future = executor.submit(run_in_new_loop) future.result() # Wait for completion # Verify the results assert len(results) == 3 # First yield should have original values assert results[0] == (1, "req-12345", "user-6789") # Second yield should have modified user_id assert results[1] == (2, "req-12345", "user-modified") # Third yield should have both modified values > assert results[2] == (3, "req-modified", "user-modified") E AssertionError: assert (3, 'req-modified', 'user-6789') == (3, 'req-modified', 'user-modified') E E At index 2 diff: 'user-6789' != 'user-modified' E E Full diff: E ( E 3, E 'req-modified', E - 'user-modified', E + 'user-6789', E ) tests/unit/distribution/test_context.py:155: AssertionError -------------------------------------------------- Captured log call -------------------------------------------------- ERROR asyncio:base_events.py:1758 Task was destroyed but it is pending! task: <Task pending name='Task-7' coro=<<async_generator_athrow without __name__>()>> ================================================== warnings summary =================================================== .venv/lib/python3.10/site-packages/pydantic/fields.py:1042 /Users/leseb/Documents/AI/llama-stack/.venv/lib/python3.10/site-packages/pydantic/fields.py:1042: PydanticDeprecatedSince20: Using extra keyword arguments on `Field` is deprecated and will be removed. Use `json_schema_extra` instead. (Extra keys: 'contentEncoding'). Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.10/migration/ warn( -- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html =============================================== short test summary info =============================================== FAILED tests/unit/distribution/test_context.py::test_preserve_contexts_across_event_loops - AssertionError: assert (3, 'req-modified', 'user-6789') == (3, 'req-modified', 'user-modified') At index 2 diff: 'user-6789' != 'user-modified' Full diff: ( 3, 'req-modified', - 'user-modified', + 'user-6789', ) ``` [//]: # (## Documentation) Signed-off-by: Sébastien Han <seb@redhat.com> |
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docs | ||
llama_stack | ||
rfcs | ||
scripts | ||
tests | ||
.gitignore | ||
.pre-commit-config.yaml | ||
.readthedocs.yaml | ||
CHANGELOG.md | ||
CODE_OF_CONDUCT.md | ||
CONTRIBUTING.md | ||
LICENSE | ||
MANIFEST.in | ||
pyproject.toml | ||
README.md | ||
requirements.txt | ||
SECURITY.md | ||
uv.lock |
Llama Stack
Quick Start | Documentation | Colab Notebook
✨🎉 Llama 4 Support 🎉✨
We released Version 0.2.0 with support for the Llama 4 herd of models released by Meta.
You can now 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!
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 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 |
---|---|---|---|---|---|---|
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 | ✅ |
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 |
Meta Reference Quantized | llamastack/distribution-meta-reference-quantized-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.
- CLI references
- llama (server-side) CLI Reference: Guide for using the
llama
CLI to work with Llama models (download, study prompts), and building/starting a Llama Stack distribution. - llama (client-side) CLI Reference: Guide for using the
llama-stack-client
CLI, which allows you to query information about the distribution.
- llama (server-side) CLI Reference: Guide for using the
- Getting Started
- Quick guide to start a Llama Stack server.
- Jupyter notebook to walk-through how to use simple text and vision inference llama_stack_client APIs
- The complete Llama Stack lesson Colab notebook of the new Llama 3.2 course on Deeplearning.ai.
- A Zero-to-Hero Guide that guide you through all the key components of llama stack with code samples.
- Contributing
- Adding a new API Provider to walk-through how to add a new API provider.
Llama Stack Client SDKs
Language | Client SDK | Package |
---|---|---|
Python | llama-stack-client-python | |
Swift | llama-stack-client-swift | |
Typescript | llama-stack-client-typescript | |
Kotlin | llama-stack-client-kotlin |
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.