LlamaIndex

LlamaIndex is a data framework for building LLM applications over your own data, including RAG pipelines, query engines, and multi-agent systems. By setting api_base to the gateway URL, all LlamaIndex LLM calls route through Portkey.

Installation

Start the gateway

Local (npx)
Portkey Cloud

npx @portkey-ai/gateway

The gateway listens at http://localhost:8787/v1.

Install dependencies

pip install llama-index llama-index-llms-openai portkey-ai

Basic setup

Set api_base on the OpenAI LLM class to point at the gateway.

from llama_index.llms.openai import OpenAI

llm = OpenAI(
    model="gpt-4o",
    api_base="http://localhost:8787/v1",
    api_key="sk-***"
)

response = llm.complete("What is the Portkey AI Gateway?")
print(response.text)

Adding routing configs via headers

Pass gateway configs through default_headers to enable retries, caching, fallbacks, and other features.

from llama_index.llms.openai import OpenAI
import json

config = {
    "retry": {"attempts": 3},
    "cache": {"mode": "simple"}
}

llm = OpenAI(
    model="gpt-4o",
    api_base="http://localhost:8787/v1",
    api_key="sk-***",
    default_headers={
        "x-portkey-config": json.dumps(config)
    }
)

from llama_index.llms.openai import OpenAI
from portkey_ai import PORTKEY_GATEWAY_URL, createHeaders

gpt_4o_config = {
    "provider": "openai",
    "api_key": "sk-***",
    "override_params": {"model": "gpt-4o"}
}

llm = OpenAI(
    api_base=PORTKEY_GATEWAY_URL,
    default_headers=createHeaders(
        api_key="YOUR_PORTKEY_API_KEY",
        config=gpt_4o_config
    )
)

response = llm.complete("Explain LLM routing in one sentence.")
print(response.text)

Using in a query engine

Once the LLM is configured, pass it to Settings and build any LlamaIndex index or query engine as normal.

from llama_index.core import VectorStoreIndex, SimpleDirectoryReader, Settings
from llama_index.llms.openai import OpenAI

Settings.llm = OpenAI(
    model="gpt-4o",
    api_base="http://localhost:8787/v1",
    api_key="sk-***"
)

# Load documents and build an index
documents = SimpleDirectoryReader("./docs").load_data()
index = VectorStoreIndex.from_documents(documents)

# Query the index
query_engine = index.as_query_engine()
response = query_engine.query("What topics are covered in the docs?")
print(response)

Real-world use case: multi-agent system with multiple LLMs

Route different agents to different LLMs through the gateway, with full observability over every request.

from llama_index.llms.openai import OpenAI
from llama_index.core.agent import ReActAgent
from llama_index.core.tools import FunctionTool
from portkey_ai import PORTKEY_GATEWAY_URL, createHeaders

# Orchestrator using GPT-4o
gpt_4o_config = {
    "provider": "openai",
    "api_key": "sk-***",
    "override_params": {"model": "gpt-4o"}
}

gpt_4o = OpenAI(
    api_base=PORTKEY_GATEWAY_URL,
    default_headers=createHeaders(
        api_key="YOUR_PORTKEY_API_KEY",
        config=gpt_4o_config
    )
)

# Worker using a faster model
llama3_config = {
    "provider": "groq",
    "api_key": "gsk-***",
    "override_params": {"model": "llama3-70b-8192"}
}

llama3 = OpenAI(
    api_base=PORTKEY_GATEWAY_URL,
    default_headers=createHeaders(
        api_key="YOUR_PORTKEY_API_KEY",
        config=llama3_config
    )
)


def get_the_secret_fact() -> str:
    """Returns the secret fact."""
    return "A baby llama is called a 'Cria'."


tool = FunctionTool.from_defaults(fn=get_the_secret_fact)

agent1 = ReActAgent.from_tools([tool], llm=llama3)
agent2 = ReActAgent.from_tools([], llm=llama3)

When using the hosted gateway, all LlamaIndex requests appear in the Portkey observability dashboard with token counts, latency, and cost — without any additional instrumentation.

Get Started

Deployment

Core Concepts

Guardrails

MCP Gateway

Integrations

Plugin Development

Installation

Basic setup

Adding routing configs via headers

Using in a query engine

Real-world use case: multi-agent system with multiple LLMs

​Installation

​Basic setup

​Adding routing configs via headers

​Using in a query engine

​Real-world use case: multi-agent system with multiple LLMs

Installation

Basic setup

Adding routing configs via headers

Using in a query engine

Real-world use case: multi-agent system with multiple LLMs