Tracing quickstart

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 the Respan SDK alongside your LLM SDK. Initialize Respan once, before your first model call. Your model calls are then traced with no other changes.

pip install respan-ai openai

from openai import OpenAI
from respan import Respan

respan = Respan()  # reads RESPAN_API_KEY
client = OpenAI()  # reads OPENAI_API_KEY

response = client.chat.completions.create(
    model="gpt-5.5",
    messages=[{"role": "user", "content": "How do I rotate my API key?"}],
)
print(response.choices[0].message.content)

npm install @respan/respan openai

import OpenAI from "openai";
import { Respan } from "@respan/respan";

const respan = new Respan(); // reads RESPAN_API_KEY
await respan.initialize();
const client = new OpenAI(); // reads OPENAI_API_KEY

const response = await client.chat.completions.create({
  model: "gpt-5.5",
  messages: [{ role: "user", content: "How do I rotate my API key?" }],
});
console.log(response.choices[0].message.content);

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.

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

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.

Go to Observability › Logs. Your openai.chat span is at the top, with its model, duration, tokens, and cost. Click it to see the 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.