Tracing quickstart

Create an API key

In the platform, go to Gateway › API keys and click New key. Pick Production or Test, keep the default permissions, and click Create.

Click Copy, then Done. You won’t see the key again, so save it now:

export RESPAN_API_KEY="your-respan-api-key"

Install and initialize the SDK

Install the Respan SDK alongside your LLM SDK. Initialize Respan once, before your first model call.

pip install respan-ai openai

from openai import OpenAI
from respan import Respan, workflow
respan = Respan()  # reads RESPAN_API_KEY
client = OpenAI()  # reads OPENAI_API_KEY
@workflow(name="support_agent")
def support_agent(question: str) -> str:
    response = client.chat.completions.create(
        model="gpt-5.5",
        messages=[{"role": "user", "content": question}],
    )
    return response.choices[0].message.content
print(support_agent("How do I rotate my API key?"))

Calls made with the OpenAI, Anthropic, AWS Bedrock, Vertex AI, and Together AI SDKs are traced automatically, plus Google GenAI and Ollama in Python, and Cohere, OpenRouter, and Writer in TypeScript. The workflow wrapper groups the calls inside it into one trace.

Using an agent framework such as OpenAI Agents, LangChain, or the Vercel AI SDK? Find its guide in Integrations.

Run your app

export OPENAI_API_KEY="your-openai-api-key"
python app.py        # TypeScript: npx tsx app.mts

The SDK sends spans in the background and flushes them when the process exits. In serverless functions, call respan.flush() (await respan.flush() in TypeScript) before you return.

See the trace in Logs

Go to Observability › Logs. Open the grouping menu, which shows Spans by default, and pick Traces. Click your support_agent trace.

The side panel shows the span tree with each span’s duration, tokens, and cost. Click a span to see its input and output.

Don’t see it? Widen the time range. Traces sent with a Test key show under Test, so set the environment switch to Test or All environments. See Inspect spans and traces.