openrouter-tool-agent

OpenRouter Tool Agent

ReAct-style agent with OpenRouter streaming and tool use, instrumented with TraceRoot.

OpenRouter provides a unified API to 200+ models (Claude, Llama, Gemini, Mistral, GPT-4o, etc.). Since it's OpenAI-compatible, TraceRoot's OpenAI integration captures all calls automatically — no extra configuration needed.

Setup

cp .env.example .env # fill in OPENROUTER_API_KEY and TRACEROOT_API_KEY

With uv (recommended):

uv run --no-project --python 3.13 --with-requirements requirements.txt python main.py

Or with pip:

pip install -r requirements.txt
python main.py

What it does

Runs two demo queries that exercise tool use:

1. Weather comparison (San Francisco vs Tokyo)
2. Stock price lookup + calculation (NVDA +10%)

Tools: get_weather, get_stock_price, calculate, get_current_time

Model selection

Change the model by passing a different OpenRouter model string to ReActAgent():

agent = ReActAgent(model="nvidia/nemotron-3-nano-omni-30b-a3b-reasoning:free")
agent = ReActAgent(model="anthropic/claude-sonnet-4")
agent = ReActAgent(model="meta-llama/llama-4-maverick")

See openrouter.ai/models for the full list.

TraceRoot UI

After running the example, open app.traceroot.ai to view the captured trace. You'll see the full agent span, nested LLM calls, and individual tool invocations with their inputs and outputs.