---
title: Agent with Query Engine Tools
 | LlamaIndex OSS Documentation
---

## Build Query Engine Tools

If you’re opening this Notebook on colab, you will probably need to install LlamaIndex 🦙.

```
%pip install llama-index
```

```
import os


os.environ["OPENAI_API_KEY"] = "sk-..."
```

```
from llama_index.llms.openai import OpenAI
from llama_index.embeddings.openai import OpenAIEmbedding
from llama_index.core import Settings


Settings.llm = OpenAI(model="gpt-4o-mini")
Settings.embed_model = OpenAIEmbedding(model="text-embedding-3-small")
```

```
from llama_index.core import StorageContext, load_index_from_storage


try:
    storage_context = StorageContext.from_defaults(
        persist_dir="./storage/lyft"
    )
    lyft_index = load_index_from_storage(storage_context)


    storage_context = StorageContext.from_defaults(
        persist_dir="./storage/uber"
    )
    uber_index = load_index_from_storage(storage_context)


    index_loaded = True
except:
    index_loaded = False
```

Download Data

```
!mkdir -p 'data/10k/'
!wget 'https://raw.githubusercontent.com/run-llama/llama_index/main/docs/examples/data/10k/uber_2021.pdf' -O 'data/10k/uber_2021.pdf'
!wget 'https://raw.githubusercontent.com/run-llama/llama_index/main/docs/examples/data/10k/lyft_2021.pdf' -O 'data/10k/lyft_2021.pdf'
```

```
from llama_index.core import SimpleDirectoryReader, VectorStoreIndex


if not index_loaded:
    # load data
    lyft_docs = SimpleDirectoryReader(
        input_files=["./data/10k/lyft_2021.pdf"]
    ).load_data()
    uber_docs = SimpleDirectoryReader(
        input_files=["./data/10k/uber_2021.pdf"]
    ).load_data()


    # build index
    lyft_index = VectorStoreIndex.from_documents(lyft_docs)
    uber_index = VectorStoreIndex.from_documents(uber_docs)


    # persist index
    lyft_index.storage_context.persist(persist_dir="./storage/lyft")
    uber_index.storage_context.persist(persist_dir="./storage/uber")
```

```
lyft_engine = lyft_index.as_query_engine(similarity_top_k=3)
uber_engine = uber_index.as_query_engine(similarity_top_k=3)
```

```
from llama_index.core.tools import QueryEngineTool


query_engine_tools = [
    QueryEngineTool.from_defaults(
        query_engine=lyft_engine,
        name="lyft_10k",
        description=(
            "Provides information about Lyft financials for year 2021. "
            "Use a detailed plain text question as input to the tool."
        ),
    ),
    QueryEngineTool.from_defaults(
        query_engine=uber_engine,
        name="uber_10k",
        description=(
            "Provides information about Uber financials for year 2021. "
            "Use a detailed plain text question as input to the tool."
        ),
    ),
]
```

## Setup Agent

For LLMs like OpenAI that have a function calling API, we should use the `FunctionAgent`.

For other LLMs, we can use the `ReActAgent`.

```
from llama_index.core.agent.workflow import FunctionAgent, ReActAgent
from llama_index.core.workflow import Context


agent = FunctionAgent(tools=query_engine_tools, llm=OpenAI(model="gpt-4o"))


# context to hold the session/state
ctx = Context(agent)
```

## Let’s Try It Out!

```
from llama_index.core.agent.workflow import ToolCallResult, AgentStream


handler = agent.run("What's the revenue for Lyft in 2021 vs Uber?", ctx=ctx)


async for ev in handler.stream_events():
    if isinstance(ev, ToolCallResult):
        print(
            f"Call {ev.tool_name} with args {ev.tool_kwargs}\nReturned: {ev.tool_output}"
        )
    elif isinstance(ev, AgentStream):
        print(ev.delta, end="", flush=True)


response = await handler
```

```
Call lyft_10k with args {'input': "What was Lyft's revenue for the year 2021?"}
Returned: Lyft's revenue for the year 2021 was $3,208,323,000.
Call uber_10k with args {'input': "What was Uber's revenue for the year 2021?"}
Returned: Uber's revenue for the year 2021 was $17.455 billion.
In 2021, Lyft's revenue was approximately $3.21 billion, while Uber's revenue was significantly higher at $17.455 billion.
```