Composable building blocks to build Llama Apps https://llama-stack.readthedocs.io
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Francisco Arceo 8e7ab146f8
feat: Adding support for customizing chunk context in RAG insertion and querying (#2134)
# What does this PR do?
his PR allows users to customize the template used for chunks when
inserted into the context. Additionally, this enables metadata injection
into the context of an LLM for RAG. This makes a naive and crude
assumption that each chunk should include the metadata, this is
obviously redundant when multiple chunks are returned from the same
document. In order to remove any sort of duplication of chunks, we'd
have to make much more significant changes so this is a reasonable first
step that unblocks users requesting this enhancement in
https://github.com/meta-llama/llama-stack/issues/1767.

In the future, this can be extended to support citations.


List of Changes:
- `llama_stack/apis/tools/rag_tool.py`
    - Added  `chunk_template` field in `RAGQueryConfig`.
- Added `field_validator` to validate the `chunk_template` field in
`RAGQueryConfig`.
- Ensured the `chunk_template` field includes placeholders `{index}` and
`{chunk.content}`.
- Updated the `query` method to use the `chunk_template` for formatting
chunk text content.
- `llama_stack/providers/inline/tool_runtime/rag/memory.py`
- Modified the `insert` method to pass `doc.metadata` for chunk
creation.
- Enhanced the `query` method to format results using `chunk_template`
and exclude unnecessary metadata fields like `token_count`.
- `llama_stack/providers/utils/memory/vector_store.py`
- Updated `make_overlapped_chunks` to include metadata serialization and
token count for both content and metadata.
    - Added error handling for metadata serialization issues.
- `pyproject.toml`
- Added `pydantic.field_validator` as a recognized `classmethod`
decorator in the linting configuration.
- `tests/integration/tool_runtime/test_rag_tool.py`
- Refactored test assertions to separate `assert_valid_chunk_response`
and `assert_valid_text_response`.
- Added integration tests to validate `chunk_template` functionality
with and without metadata inclusion.
- Included a test case to ensure `chunk_template` validation errors are
raised appropriately.
- `tests/unit/rag/test_vector_store.py`
- Added unit tests for `make_overlapped_chunks`, verifying chunk
creation with overlapping tokens and metadata integrity.
- Added tests to handle metadata serialization errors, ensuring proper
exception handling.
- `docs/_static/llama-stack-spec.html`
- Added a new `chunk_template` field of type `string` with a default
template for formatting retrieved chunks in RAGQueryConfig.
    - Updated the `required` fields to include `chunk_template`.
- `docs/_static/llama-stack-spec.yaml`
- Introduced `chunk_template` field with a default value for
RAGQueryConfig.
- Updated the required configuration list to include `chunk_template`.
- `docs/source/building_applications/rag.md`
- Documented the `chunk_template` configuration, explaining how to
customize metadata formatting in RAG queries.
- Added examples demonstrating the usage of the `chunk_template` field
in RAG tool queries.
    - Highlighted default values for `RAG` agent configurations.

# Resolves https://github.com/meta-llama/llama-stack/issues/1767

## Test Plan
Updated both `test_vector_store.py` and `test_rag_tool.py` and tested
end-to-end with a script.

I also tested the quickstart to enable this and specified this metadata:
```python
document = RAGDocument(
    document_id="document_1",
    content=source,
    mime_type="text/html",
    metadata={"author": "Paul Graham", "title": "How to do great work"},
)
```
Which produced the output below: 

![Screenshot 2025-05-13 at 10 53
43 PM](https://github.com/user-attachments/assets/bb199d04-501e-4217-9c44-4699d43d5519)

This highlights the usefulness of the additional metadata. Notice how
the metadata is redundant for different chunks of the same document. I
think we can update that in a subsequent PR.

# Documentation
I've added a brief comment about this in the documentation to outline
this to users and updated the API documentation.

---------

Signed-off-by: Francisco Javier Arceo <farceo@redhat.com>
2025-05-14 21:56:20 -04:00
.github chore: enforce no git tags or branches in external github actions (#2159) 2025-05-14 20:40:06 +02:00
docs feat: Adding support for customizing chunk context in RAG insertion and querying (#2134) 2025-05-14 21:56:20 -04:00
llama_stack feat: Adding support for customizing chunk context in RAG insertion and querying (#2134) 2025-05-14 21:56:20 -04:00
rfcs chore: remove straggler references to llama-models (#1345) 2025-03-01 14:26:03 -08:00
scripts chore: enforce no git tags or branches in external github actions (#2159) 2025-05-14 20:40:06 +02:00
tests feat: Adding support for customizing chunk context in RAG insertion and querying (#2134) 2025-05-14 21:56:20 -04:00
.coveragerc chore: exclude test, provider, and template directories from coverage (#2028) 2025-04-25 12:16:57 -07:00
.gitignore build: remove .python-version (#1513) 2025-03-12 20:08:24 -07:00
.pre-commit-config.yaml chore: enforce no git tags or branches in external github actions (#2159) 2025-05-14 20:40:06 +02:00
.readthedocs.yaml first version of readthedocs (#278) 2024-10-22 10:15:58 +05:30
CHANGELOG.md docs: Update changelog to include recent releases (#2108) 2025-05-06 14:42:06 -07:00
CODE_OF_CONDUCT.md Initial commit 2024-07-23 08:32:33 -07:00
CONTRIBUTING.md docs: revamp testing documentation (#2155) 2025-05-13 11:28:29 -07:00
install.sh fix(installer): harden install.sh for Podman macOS (#2068) 2025-05-05 00:31:58 -07:00
LICENSE Update LICENSE (#47) 2024-08-29 07:39:50 -07:00
MANIFEST.in feat: introduce llama4 support (#1877) 2025-04-05 11:53:35 -07:00
pyproject.toml feat: Adding support for customizing chunk context in RAG insertion and querying (#2134) 2025-05-14 21:56:20 -04:00
README.md docs: Add link to Discord to README (#2126) 2025-05-10 18:32:44 -07:00
requirements.txt chore: rehydrate requirements.txt (#2146) 2025-05-12 12:45:35 -07:00
SECURITY.md Create SECURITY.md 2024-10-08 13:30:40 -04:00
uv.lock build: Bump version to 0.2.6 2025-05-12 18:02:05 +00:00

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 | sh

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
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

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.