Nexus | Agno

Nexus is a routing platform that provides endpoints for various Large Language Models through a unified API interface.

Explore Nexus's capabilities and documentation here.

Start the gateway

Nexus routes this example to Anthropic. Configure the provider key in the gateway process, not just in the Python client's shell.

Set up your virtual environment

uv venv --python 3.12
source .venv/bin/activate

Configure Nexus

Install Nexus, then create nexus.toml in the directory where you will start the gateway:

[server]
listen_address = "127.0.0.1:8000"

[llm]
enabled = true

[llm.protocols.openai]
enabled = true
path = "/llm"

[llm.providers.anthropic]
type = "anthropic"
api_key = "{{ env.ANTHROPIC_API_KEY }}"

[llm.providers.anthropic.models."claude-sonnet-4-6"]

The Nexus model sends OpenAI-compatible requests to http://localhost:8000/llm/v1/ by default. Nexus requires every model to be declared in nexus.toml.

Start Nexus

In a dedicated server terminal, set the provider key and start the gateway from the directory that contains nexus.toml:

export ANTHROPIC_API_KEY="your-anthropic-api-key"
nexus

Leave this terminal running. The provider key belongs to the Nexus process. Open a second terminal in your example directory, activate the Python virtual environment there, and run the Agno client. Exporting the key only in that client terminal does not configure the gateway.

In the second terminal with the environment activated, install the client dependencies:

uv pip install -U agno openai

Example

Save the following as agent.py and run python agent.py in the client terminal:

from agno.agent import Agent
from agno.models.nexus import Nexus

agent = Agent(model=Nexus(id="anthropic/claude-sonnet-4-6"), markdown=True)

# Print the response in the terminal
agent.print_response("Share a 2 sentence horror story")

View more examples here.

Params

Parameter	Type	Default	Description
`id`	`str`	`"openai/gpt-4"`	The id of the model to use through Nexus
`name`	`str`	`"Nexus"`	The name of the model
`provider`	`str`	`"Nexus"`	The provider of the model
`api_key`	`Optional[str]`	`"not-provided"`	The API key sent to the Nexus router. Not required for a local deployment
`base_url`	`str`	`"http://localhost:8000/llm/v1/"`	The base URL for the Nexus API

Nexus also supports the params of OpenAI.