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@bryel/browser traces AI-SDK calls that run in the browser — when your agent issues model calls from client code rather than a server. Same OpenInference spans as the server SDK, batched and non-blocking, with no app-boot cost.
If your model calls run on a server, use TypeScript instead — it adds nothing to your client bundle.
1

Create a browser key

In the dashboard, open Developer → API keys → Browser key and list the origins your app runs on (e.g. https://app.example.com). You get a publishable bkp_… key: write-only and locked to those origins, so it is safe to ship in client code.
2

Install

bun add @bryel/browser
3

Create a tracer and pass it per call

Build the tracer where you trace — not at app boot — and hand it to the AI SDK. Spans flush in the background.
import { createBryelTracer } from "@bryel/browser";
import { streamText } from "ai";

const tracer = createBryelTracer({ apiKey: "bkp_…", serviceName: "studio-agent" });

await streamText({
  model,
  experimental_telemetry: { isEnabled: true, tracer, metadata: { sessionId, userId } },
  prompt,
});

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Why it won’t slow your app

  • No app-boot cost. With createBryelTracer you build the tracer only where you trace; nothing runs at startup, and the package lazy-imports.
  • Non-blocking. Spans batch and POST in the background, off your request path — calls never wait on export, and export failures are swallowed.
  • ~21 KB gzipped, all-in. Lazy-load it so it stays off your critical path.

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Excluding traffic

Capture is per call. Gate isEnabled on your own logic to skip a cohort — e.g. isEnabled: tier !== "enterprise" — and those calls emit no spans; their data never leaves the browser.

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Global registration (optional)

If your app has no other OpenTelemetry setup, register a global provider and drop the tracer: 
import { registerBryelBrowser } from "@bryel/browser";

registerBryelBrowser({ apiKey: "bkp_…", serviceName: "studio-agent" });
// then: experimental_telemetry: { isEnabled: true }
Use a publishable bkp_ key in the browser — never a secret bk_ key. A browser bundle is public; bkp_ keys are write-only and origin-locked.

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API

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createBryelTracer(options): Tracer

Returns an OpenTelemetry Tracer to pass into experimental_telemetry.tracer. No global registration — build it where you trace.

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registerBryelBrowser(options): WebTracerProvider

Registers a global browser provider; returns it for forceFlush() / shutdown().

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Options

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apiKey
string
required
A publishable key (bkp_…) — write-only, origin-locked. Never a secret bk_ key.
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endpoint
string
default:"https://ingest.eu.bryel.ai/v1/traces"
OTLP/HTTP endpoint. Override for self-hosting.
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serviceName
string
OpenTelemetry service.name.
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headers
Record<string, string>
Extra headers, merged after auth.