Tool Use

Call WebSearchTools from Claude Sonnet 4 routed through the Nexus gateway.

The source routes requests to Anthropic’s retired claude-sonnet-4-20250514 model. Replace it with anthropic/claude-sonnet-4-6 before running. See Anthropic model deprecations.

tool_use.py

"""Run `uv pip install ddgs` to install dependencies."""

import asyncio

from agno.agent import Agent
from agno.models.nexus import Nexus
from agno.tools.websearch import WebSearchTools

# ---------------------------------------------------------------------------
# Create Agent
# ---------------------------------------------------------------------------

agent = Agent(
    model=Nexus(id="anthropic/claude-sonnet-4-20250514"),
    tools=[WebSearchTools()],
    markdown=True,
)

# ---------------------------------------------------------------------------
# Run Agent
# ---------------------------------------------------------------------------
if __name__ == "__main__":
    # --- Sync ---
    agent.print_response("Whats happening in France?")

    # --- Sync + Streaming ---
    agent.print_response("Whats happening in France?", stream=True)

    # --- Async ---
    asyncio.run(agent.aprint_response("Whats happening in France?"))

    # --- Async + Streaming ---
    asyncio.run(agent.aprint_response("Whats happening in France?", stream=True))

Run the Example

1. Set up your virtual environment

   Mac

   uv venv --python 3.12
   source .venv/bin/activate
   
2. Install dependencies

   uv pip install -U agno ddgs openai
   
3. Export your API keys

   Mac/Linux

   export ANTHROPIC_API_KEY="your_anthropic_api_key_here"
   export OPENAI_API_KEY="your_openai_api_key_here"
   
4. Use a current Claude model

   Replace anthropic/claude-sonnet-4-20250514 with anthropic/claude-sonnet-4-6 in the saved file.

5. Configure Nexus

   Install Nexus, then create nexus.toml for the Anthropic model and the /llm/v1/ endpoint used by Agno:

   cat > nexus.toml <<'TOML'
   [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"]
   TOML
   
6. Start Nexus

   Start the gateway from the directory that contains nexus.toml:

   nexus
   
7. Run the example

   Save the code above as tool_use.py, then run:

   python tool_use.py
   

Full source: cookbook/90_models/nexus/tool_use.py