TypeScript and JavaScript SDK

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Add Bench using https://docs.usebench.ai/sdk/typescript and my Bench SDK setup prompt.
Use its installation source, endpoint and server-side key. Match this repository's
TypeScript or JavaScript style. Start with metadata-only capture in staging.
Wrap a real awaited operation and its tools with bench.trace. Preserve the full
stream lifecycle, flush a synthetic event, and confirm receipt in Bench.
Show changed files and any remaining setup steps.

This is a preview. Use the installation command from Bench; the public npm package is not released yet.

Record one interaction

Copy the installation command from SDK in your Bench account and run it in your server project. The command uses the SDK build available to your account. Create a repository-scoped key there and keep it in your server’s secret store.

import { Bench } from '@trybench/sdk'

const bench = new Bench({
  apiKey: process.env.BENCH_API_KEY!,
  repository: process.env.BENCH_REPOSITORY!,
  branch: process.env.BENCH_BRANCH!,
  endpoint: process.env.BENCH_API_BASE_URL,
  systemName: 'Support agent',
  environment: process.env.BENCH_ENVIRONMENT ?? 'development',
  captureContent: false,
})

// One synthetic event: no customer content or model request.
await bench.trace(
  { name: 'SDK connection check', kind: 'AGENT' },
  () => ({ ok: true }),
)
await bench.shutdown() // Flush before this one-shot script exits.

Use Node.js 20+ on the server. Never use public environment-variable prefixes such as NEXT_PUBLIC_ or VITE_ for the key. Set BENCH_API_BASE_URL to the endpoint shown in your account. Use the API address and installation command shown on the SDK page in your Bench account. The example uses TypeScript. In JavaScript, remove the ! non-null assertions and validate required environment variables when your server starts.

Wrap agents and tools

Replace the synthetic callback with an existing application operation. Nest tool calls with kind: 'TOOL'; awaited child calls keep their parent trace. Wrap the complete invocation for Mastra, Vercel AI SDK, LangChain, LangGraph, Deep Agents, OpenAI Agents or custom server code. These are manual wrappers. More automatic framework adapters are coming soon. For streams, keep the span open until the stream is fully consumed. Fire-and-forget work may finish after the request and needs its own lifecycle handling. captureContent defaults to false. When enabled, pass input and let the callback return the output. Built-in filters run before sending. Add a redact(value) callback for extra application fields. Read privacy and redaction. Call await bench.flush() at serverless request boundaries. Reuse the client for long-running servers and call await bench.shutdown() after active work finishes. bench.stats and onError expose delivery failures without changing app results. Set componentId to a real prompt component from Bench when linking events to criteria. Never invent IDs. SDK setup keys cannot spend evaluation credits.

Test application behavior

This client includes evaluateSystem for individual cases and simulateSystem for scripted customer conversations through your app. Both require your actual application function and test dependencies. Read application testing for complete examples, then production checks to evaluate recorded interactions. See SDK setup for connection status, environments and troubleshooting.

Run in CI

Use Bench with your existing pull-request checks. See Run tests in CI for setup, report handling and the features available in each language.

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MCP

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TypeScript and JavaScript SDK

Copy this into your coding agent

Record one interaction

Wrap agents and tools

Test application behavior

Run in CI

​Copy this into your coding agent

​Record one interaction

​Wrap agents and tools

​Test application behavior

​Run in CI

Copy this into your coding agent

Record one interaction

Wrap agents and tools

Test application behavior

Run in CI