instrumentation-auto-typescript.md

Auto-Instrumentation (TypeScript)

Automatically create spans for LLM calls without code changes.

Supported Frameworks

• LLM SDKs: OpenAI
• Frameworks: LangChain
• Install: npm install @arizeai/openinference-instrumentation-{name}

Setup

CommonJS (automatic):

const { register } = require("@arizeai/phoenix-otel");
const OpenAI = require("openai");

register({ projectName: "my-app" });

const client = new OpenAI();

ESM (manual required):

import { register, registerInstrumentations } from "@arizeai/phoenix-otel";
import { OpenAIInstrumentation } from "@arizeai/openinference-instrumentation-openai";
import OpenAI from "openai";

register({ projectName: "my-app" });

const instrumentation = new OpenAIInstrumentation();
instrumentation.manuallyInstrument(OpenAI);
registerInstrumentations({ instrumentations: [instrumentation] });

Why: ESM imports are hoisted before register() runs.

Limitations

What auto-instrumentation does NOT capture:

async function myWorkflow(query: string): Promise<string> {
  const preprocessed = await preprocess(query);        // Not traced
  const response = await client.chat.completions.create(...);  // Traced (auto)
  const postprocessed = await postprocess(response);   // Not traced
  return postprocessed;
}

Solution: Add manual instrumentation for custom logic:

import { traceChain } from "@arizeai/openinference-core";

const myWorkflow = traceChain(
  async (query: string): Promise<string> => {
    const preprocessed = await preprocess(query);
    const response = await client.chat.completions.create(...);
    const postprocessed = await postprocess(response);
    return postprocessed;
  },
  { name: "my-workflow" }
);

Combining Auto + Manual

import { register } from "@arizeai/phoenix-otel";
import { traceChain } from "@arizeai/openinference-core";

register({ projectName: "my-app" });

const client = new OpenAI();

const workflow = traceChain(
  async (query: string) => {
    const preprocessed = await preprocess(query);
    const response = await client.chat.completions.create(...);  // Auto-instrumented
    return postprocess(response);
  },
  { name: "my-workflow" }
);