Add documentations for building applications and with some content for agentic loop

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Ashwin Bharambe 2024-12-08 14:56:03 -08:00
parent a29013112f
commit 1274fa4c0d
5 changed files with 424 additions and 16 deletions

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@ -9,3 +9,4 @@ sphinx-tabs
sphinx-design sphinx-design
sphinxcontrib-openapi sphinxcontrib-openapi
sphinxcontrib-redoc sphinxcontrib-redoc
sphinxcontrib-mermaid

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@ -1,17 +1,413 @@
# Building Applications # Building AI Applications
```{admonition} Work in Progress Llama Stack provides all the building blocks needed to create sophisticated AI applications. This guide will walk you through how to use these components effectively.
:class: warning
## What can you do with the Stack? ## Basic Inference
- Agents The foundation of any AI application is the ability to interact with LLM models. Llama Stack provides a simple interface for both completion and chat-based inference:
- what is a turn? session?
- inference ```python
- memory / RAG; pre-ingesting content or attaching content in a turn from llama_stack_client import LlamaStackClient
- how does tool calling work
- can you do evaluation? client = LlamaStackClient(base_url="http://localhost:5001")
# List available models
models = client.models.list()
# Simple chat completion
response = client.inference.chat_completion(
model_id="Llama3.2-3B-Instruct",
messages=[
{"role": "system", "content": "You are a helpful assistant."},
{"role": "user", "content": "Write a haiku about coding"}
]
)
print(response.completion_message.content)
``` ```
## Adding Memory & RAG
Memory enables your applications to reference and recall information from previous interactions or external documents. Llama Stack's memory system is built around the concept of Memory Banks:
1. **Vector Memory Banks**: For semantic search and retrieval
2. **Key-Value Memory Banks**: For structured data storage
3. **Keyword Memory Banks**: For basic text search
4. **Graph Memory Banks**: For relationship-based retrieval
Here's how to set up a vector memory bank for RAG:
```python
# Register a memory bank
bank_id = "my_documents"
response = client.memory_banks.register(
memory_bank_id=bank_id,
params={
"memory_bank_type": "vector",
"embedding_model": "all-MiniLM-L6-v2",
"chunk_size_in_tokens": 512
}
)
# Insert documents
documents = [
{
"document_id": "doc1",
"content": "Your document text here",
"mime_type": "text/plain"
}
]
client.memory.insert(bank_id, documents)
# Query documents
results = client.memory.query(
bank_id=bank_id,
query="What do you know about...",
)
```
## Implementing Safety Guardrails
Safety is a critical component of any AI application. Llama Stack provides a Shield system that can be applied at multiple touchpoints:
```python
# Register a safety shield
shield_id = "content_safety"
client.shields.register(
shield_id=shield_id,
provider_shield_id="llama-guard-basic"
)
# Run content through shield
response = client.safety.run_shield(
shield_id=shield_id,
messages=[{"role": "user", "content": "User message here"}]
)
if response.violation:
print(f"Safety violation detected: {response.violation.user_message}")
```
## Building Agents
Agents are the heart of complex AI applications. They combine inference, memory, safety, and tool usage into coherent workflows. At its core, an agent follows a sophisticated execution loop that enables multi-step reasoning, tool usage, and safety checks.
### The Agent Execution Loop
Each agent turn follows these key steps:
1. **Initial Safety Check**: The user's input is first screened through configured safety shields
2. **Context Retrieval**:
- If RAG is enabled, the agent queries relevant documents from memory banks
- For new documents, they are first inserted into the memory bank
- Retrieved context is augmented to the user's prompt
3. **Inference Loop**: The agent enters its main execution loop:
- The LLM receives the augmented prompt (with context and/or previous tool outputs)
- The LLM generates a response, potentially with tool calls
- If tool calls are present:
- Tool inputs are safety-checked
- Tools are executed (e.g., web search, code execution)
- Tool responses are fed back to the LLM for synthesis
- The loop continues until:
- The LLM provides a final response without tool calls
- Maximum iterations are reached
- Token limit is exceeded
4. **Final Safety Check**: The agent's final response is screened through safety shields
```{mermaid}
sequenceDiagram
participant U as User
participant E as Executor
participant M as Memory Bank
participant L as LLM
participant T as Tools
participant S as Safety Shield
Note over U,S: Agent Turn Start
U->>S: 1. Submit Prompt
activate S
S->>E: Input Safety Check
deactivate S
E->>M: 2.1 Query Context
M-->>E: 2.2 Retrieved Documents
loop Inference Loop
E->>L: 3.1 Augment with Context
L-->>E: 3.2 Response (with/without tool calls)
alt Has Tool Calls
E->>S: Check Tool Input
S->>T: 4.1 Execute Tool
T-->>E: 4.2 Tool Response
E->>L: 5.1 Tool Response
L-->>E: 5.2 Synthesized Response
end
opt Stop Conditions
Note over E: Break if:
Note over E: - No tool calls
Note over E: - Max iterations reached
Note over E: - Token limit exceeded
end
end
E->>S: Output Safety Check
S->>U: 6. Final Response
```
Each step in this process can be monitored and controlled through configurations. Here's an example that demonstrates monitoring the agent's execution:
```python
from llama_stack_client.lib.agents.event_logger import EventLogger
agent_config = AgentConfig(
model="Llama3.2-3B-Instruct",
instructions="You are a helpful assistant",
# Enable both RAG and tool usage
tools=[
{
"type": "memory",
"memory_bank_configs": [{
"type": "vector",
"bank_id": "my_docs"
}],
"max_tokens_in_context": 4096
},
{
"type": "code_interpreter",
"enable_inline_code_execution": True
}
],
# Configure safety
input_shields=["content_safety"],
output_shields=["content_safety"],
# Control the inference loop
max_infer_iters=5,
sampling_params={
"temperature": 0.7,
"max_tokens": 2048
}
)
agent = Agent(client, agent_config)
session_id = agent.create_session("monitored_session")
# Stream the agent's execution steps
response = agent.create_turn(
messages=[{"role": "user", "content": "Analyze this code and run it"}],
attachments=[{
"content": "https://raw.githubusercontent.com/example/code.py",
"mime_type": "text/plain"
}],
session_id=session_id
)
# Monitor each step of execution
for log in EventLogger().log(response):
if log.event.step_type == "memory_retrieval":
print("Retrieved context:", log.event.retrieved_context)
elif log.event.step_type == "inference":
print("LLM output:", log.event.model_response)
elif log.event.step_type == "tool_execution":
print("Tool call:", log.event.tool_call)
print("Tool response:", log.event.tool_response)
elif log.event.step_type == "shield_call":
if log.event.violation:
print("Safety violation:", log.event.violation)
```
This example shows how an agent can: Llama Stack provides a high-level agent framework:
```python
from llama_stack_client.lib.agents.agent import Agent
from llama_stack_client.types.agent_create_params import AgentConfig
# Configure an agent
agent_config = AgentConfig(
model="Llama3.2-3B-Instruct",
instructions="You are a helpful assistant",
tools=[
{
"type": "memory",
"memory_bank_configs": [],
"query_generator_config": {
"type": "default",
"sep": " "
}
}
],
input_shields=["content_safety"],
output_shields=["content_safety"],
enable_session_persistence=True
)
# Create an agent
agent = Agent(client, agent_config)
session_id = agent.create_session("my_session")
# Run agent turns
response = agent.create_turn(
messages=[{"role": "user", "content": "Your question here"}],
session_id=session_id
)
```
### Adding Tools to Agents
Agents can be enhanced with various tools:
1. **Search**: Web search capabilities through providers like Brave
2. **Code Interpreter**: Execute code snippets
3. **RAG**: Memory and document retrieval
4. **Function Calling**: Custom function execution
5. **WolframAlpha**: Mathematical computations
6. **Photogen**: Image generation
Example of configuring an agent with tools:
```python
agent_config = AgentConfig(
model="Llama3.2-3B-Instruct",
tools=[
{
"type": "brave_search",
"api_key": "YOUR_API_KEY",
"engine": "brave"
},
{
"type": "code_interpreter",
"enable_inline_code_execution": True
}
],
tool_choice="auto",
tool_prompt_format="json"
)
```
## Building RAG-Enhanced Agents
One of the most powerful patterns is combining agents with RAG capabilities. Here's a complete example:
```python
from llama_stack_client.types import Attachment
# Create attachments from documents
attachments = [
Attachment(
content="https://raw.githubusercontent.com/example/doc.rst",
mime_type="text/plain"
)
]
# Configure agent with memory
agent_config = AgentConfig(
model="Llama3.2-3B-Instruct",
instructions="You are a helpful assistant",
tools=[{
"type": "memory",
"memory_bank_configs": [],
"query_generator_config": {"type": "default", "sep": " "},
"max_tokens_in_context": 4096,
"max_chunks": 10
}],
enable_session_persistence=True
)
agent = Agent(client, agent_config)
session_id = agent.create_session("rag_session")
# Initial document ingestion
response = agent.create_turn(
messages=[{
"role": "user",
"content": "I am providing some documents for reference."
}],
attachments=attachments,
session_id=session_id
)
# Query with RAG
response = agent.create_turn(
messages=[{
"role": "user",
"content": "What are the key topics in the documents?"
}],
session_id=session_id
)
```
## Testing & Evaluation
Llama Stack provides built-in tools for evaluating your applications:
1. **Benchmarking**: Test against standard datasets
2. **Application Evaluation**: Score your application's outputs
3. **Custom Metrics**: Define your own evaluation criteria
Here's how to set up basic evaluation:
```python
# Create an evaluation task
response = client.eval_tasks.register(
eval_task_id="my_eval",
dataset_id="my_dataset",
scoring_functions=["accuracy", "relevance"]
)
# Run evaluation
job = client.eval.run_eval(
task_id="my_eval",
task_config={
"type": "app",
"eval_candidate": {
"type": "agent",
"config": agent_config
}
}
)
# Get results
result = client.eval.job_result(
task_id="my_eval",
job_id=job.job_id
)
```
## Debugging & Monitoring
Llama Stack includes comprehensive telemetry for debugging and monitoring your applications:
1. **Tracing**: Track request flows across components
2. **Metrics**: Measure performance and usage
3. **Logging**: Debug issues and track behavior
The telemetry system supports multiple output formats:
- OpenTelemetry for visualization in tools like Jaeger
- SQLite for local storage and querying
- Console output for development
Example of querying traces:
```python
# Query traces for a session
traces = client.telemetry.query_traces(
attribute_filters=[{
"key": "session_id",
"op": "eq",
"value": session_id
}]
)
# Get detailed span information
span_tree = client.telemetry.get_span_tree(
span_id=traces[0].root_span_id
)
```
For details on how to use the telemetry system to debug your applications, export traces to a dataset, and run evaluations, see the [Telemetry](telemetry) section. For details on how to use the telemetry system to debug your applications, export traces to a dataset, and run evaluations, see the [Telemetry](telemetry) section.
```{toctree} ```{toctree}

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@ -28,6 +28,7 @@ extensions = [
"sphinx_tabs.tabs", "sphinx_tabs.tabs",
"sphinx_design", "sphinx_design",
"sphinxcontrib.redoc", "sphinxcontrib.redoc",
"sphinxcontrib.mermaid",
] ]
myst_enable_extensions = ["colon_fence"] myst_enable_extensions = ["colon_fence"]
@ -47,6 +48,7 @@ exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
myst_enable_extensions = [ myst_enable_extensions = [
"amsmath", "amsmath",
"attrs_inline", "attrs_inline",
"attrs_block",
"colon_fence", "colon_fence",
"deflist", "deflist",
"dollarmath", "dollarmath",
@ -65,6 +67,7 @@ myst_substitutions = {
"docker_hub": "https://hub.docker.com/repository/docker/llamastack", "docker_hub": "https://hub.docker.com/repository/docker/llamastack",
} }
# Copy button settings # Copy button settings
copybutton_prompt_text = "$ " # for bash prompts copybutton_prompt_text = "$ " # for bash prompts
copybutton_prompt_is_regexp = True copybutton_prompt_is_regexp = True

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@ -81,6 +81,8 @@ A few things to note:
- The configuration dictionary is provider-specific. Notice that configuration can reference environment variables (with default values), which are expanded at runtime. When you run a stack server (via docker or via `llama stack run`), you can specify `--env OLLAMA_URL=http://my-server:11434` to override the default value. - The configuration dictionary is provider-specific. Notice that configuration can reference environment variables (with default values), which are expanded at runtime. When you run a stack server (via docker or via `llama stack run`), you can specify `--env OLLAMA_URL=http://my-server:11434` to override the default value.
## Resources ## Resources
```
Finally, let's look at the `models` section: Finally, let's look at the `models` section:
```yaml ```yaml
models: models:

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@ -19,16 +19,17 @@ export LLAMA_STACK_PORT=5001
ollama run $OLLAMA_INFERENCE_MODEL --keepalive 60m 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 enspagents/agenure the model remains loaded for sometime. 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 ### 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. 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.
```bash ```bash
docker run \ docker run -it \
-it \
-p $LLAMA_STACK_PORT:$LLAMA_STACK_PORT \ -p $LLAMA_STACK_PORT:$LLAMA_STACK_PORT \
-v ~/.llama:/root/.llama \ -v ~/.llama:/root/.llama \
llamastack/distribution-ollama \ llamastack/distribution-ollama \
@ -42,8 +43,7 @@ Configuration for this is available at `distributions/ollama/run.yaml`.
### 3. Use the Llama Stack client SDK ### 3. Use the Llama Stack client SDK
You can interact with the Llama Stack server using the `llama-stack-client` CLI or via the Python SDK. You can interact with the Llama Stack server using various client SDKs. We will use the Python SDK which you can install using:
```bash ```bash
pip install llama-stack-client pip install llama-stack-client
``` ```
@ -123,7 +123,6 @@ async def run_main():
agent = Agent(client, agent_config) agent = Agent(client, agent_config)
session_id = agent.create_session("test-session") session_id = agent.create_session("test-session")
print(f"Created session_id={session_id} for Agent({agent.agent_id})")
user_prompts = [ user_prompts = [
( (
"I am attaching documentation for Torchtune. Help me answer questions I will ask next.", "I am attaching documentation for Torchtune. Help me answer questions I will ask next.",
@ -154,3 +153,10 @@ if __name__ == "__main__":
- Learn how to [Build Llama Stacks](../distributions/index.md) - Learn how to [Build Llama Stacks](../distributions/index.md)
- See [References](../references/index.md) for more details about the llama CLI and Python SDK - See [References](../references/index.md) for more details about the llama CLI and Python SDK
- For example applications and more detailed tutorials, visit our [llama-stack-apps](https://github.com/meta-llama/llama-stack-apps/tree/main/examples) repository. - For example applications and more detailed tutorials, visit our [llama-stack-apps](https://github.com/meta-llama/llama-stack-apps/tree/main/examples) repository.
## Thinking out aloud here in terms of what to write in the docs
- how to get a llama stack server running
- what are all the different client sdks
- what are the components of building agents