> ## Documentation Index
> Fetch the complete documentation index at: https://asymptotelabs-fix-postinstall-refresh-user-hooks.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Anthropic

> Instrument Anthropic SDK calls with Asymptote Observe

## Integration Overview

Use this integration when your application calls Anthropic's `@anthropic-ai/sdk` TypeScript package directly. Asymptote Observe uses OpenLLMetry's Anthropic instrumentation so Anthropic model calls flow through the same exporter and Beacon-compatible attribute path as the rest of your agent telemetry.

## Overview

Initialize Asymptote Observe before creating the Anthropic client when possible. The instrumentation captures supported Anthropic SDK spans without changing the way you call `anthropic.messages.create()`.

Using Claude Agent SDK instead of the direct provider SDK? See [Claude Agent SDK](/sdk/integrations-claude-agent-sdk).

## What Asymptote Captures

* Anthropic model calls emitted by the OpenLLMetry Anthropic instrumentation.
* OpenTelemetry resource attributes such as service name, SDK version, `beacon.origin=cloud`, and export mode.
* Beacon compatibility hints where supported by the SDK and instrumentation path.
* Errors recorded on failed spans.

## Prerequisites

* Node.js 20 or newer.
* `@asymptote/sdk` installed.
* `@anthropic-ai/sdk` installed.
* `ASYMPTOTE_API_KEY` set for Asymptote Managed hosted Observe, or `OTEL_EXPORTER_OTLP_ENDPOINT` set for customer-managed OTLP export. To get an Asymptote Managed API key, [reach out for a demo](https://asymptotelabs.ai/contact).

```bash title="Install the SDK and Anthropic client" theme={null}
npm install @asymptote/sdk @anthropic-ai/sdk
```

Set environment variables:

```bash title="Set Asymptote Managed and Anthropic environment variables" theme={null}
export ASYMPTOTE_API_KEY=...
export ANTHROPIC_API_KEY=...
```

## Getting Started

Initialize `Observe` before creating the Anthropic client when possible.

```typescript title="Trace Anthropic messages.create" lines theme={null}
import Anthropic from "@anthropic-ai/sdk";
import { Observe } from "@asymptote/sdk";

Observe.initialize({
  apiKey: process.env.ASYMPTOTE_API_KEY,
  instrumentationOptions: {
    anthropic: {
      traceContent: true,
    },
  },
});

const anthropic = new Anthropic({
  apiKey: process.env.ANTHROPIC_API_KEY,
});

const message = await anthropic.messages.create({
  model: "claude-sonnet-4-5",
  max_tokens: 1024,
  messages: [
    {
      role: "user",
      content: "Review this agent workflow for risky tool use.",
    },
  ],
});

await Observe.flush();
```

All supported Anthropic SDK calls are now traced through the configured Asymptote exporter.

## Already-Loaded Clients

If your application imports or creates the Anthropic client before initialization, pass the module to `instrumentModules` or patch it after initialization.

```typescript title="Instrument an already-loaded Anthropic module" lines theme={null}
import Anthropic from "@anthropic-ai/sdk";
import { Observe } from "@asymptote/sdk";

const anthropic = new Anthropic({
  apiKey: process.env.ANTHROPIC_API_KEY,
});

Observe.initialize({
  apiKey: process.env.ASYMPTOTE_API_KEY,
  instrumentModules: {
    Anthropic,
  },
});
```

## Existing OpenTelemetry Providers

If your application already owns OpenTelemetry setup, register only Asymptote's Anthropic instrumentation with your existing provider.

```typescript title="Register Anthropic instrumentation on an existing provider" lines theme={null}
import { registerInstrumentations } from "@opentelemetry/instrumentation";
import { Observe } from "@asymptote/sdk";

registerInstrumentations({
  instrumentations: Observe.instrumentations({
    openAI: false,
    anthropic: {
      traceContent: true,
    },
  }),
});
```

## Troubleshooting

* Confirm `ASYMPTOTE_API_KEY` or `OTEL_EXPORTER_OTLP_ENDPOINT` is set in the same process that runs the SDK.
* Initialize `Observe` before constructing the Anthropic client when possible.
* If the Anthropic module is imported before initialization, pass it through `instrumentModules` or `Observe.patch()`.
* Call `Observe.flush()` before short-lived scripts or jobs exit.

## What's Next

<Columns cols={2}>
  <Card title="Claude Agent SDK" icon="robot" href="/sdk/integrations-claude-agent-sdk">
    Wrap Claude Agent SDK query functions with Beacon-compatible prompt spans.
  </Card>

  <Card title="Instrumentation" icon="wand-magic-sparkles" href="/sdk/instrumentation">
    Review initialization, module patching, and existing OpenTelemetry provider setup.
  </Card>
</Columns>