LoadStrike SDK for TypeScript and JavaScript

LoadStrike is a developer-first load testing SDK for Node.js applications, services, and test suites. Use it when you want to model real transactions in code, execute them in-process, and capture structured results without moving into a separate runner or DSL.

What This SDK Is For

• Author scenario-based load tests in TypeScript or JavaScript.
• Generate safe starter scenarios from captured HAR, OpenTelemetry trace JSON, browser recordings, or message pairs with Trace-to-test Autopilot.
• Exercise HTTP and event-driven workflows across multiple steps.
• Apply load simulations, thresholds, and custom metrics to real transactions.
• Generate local reports and, on Business and Enterprise, publish observability data to supported sinks.

Built-in transport coverage includes HTTP, Kafka, RabbitMQ, NATS, Redis Streams, Azure Event Hubs, Push Diffusion, and delegate-based custom streams. Local report output supports HTML, Markdown, TXT, and CSV, and Business and Enterprise can publish to InfluxDB, TimescaleDB, Grafana Loki, Datadog, Splunk HEC, and OpenTelemetry Collector.

Requirements

• Node.js 20 or later

Install

npm install @loadstrike/loadstrike-sdk

Quick Start

import {
  LoadStrikeResponse,
  LoadStrikeRunner,
  LoadStrikeScenario,
  LoadStrikeSimulation,
  LoadStrikeStep,
} from "@loadstrike/loadstrike-sdk";

const scenario = LoadStrikeScenario
  .create("orders", async (context) => {
    return LoadStrikeStep.run(
      "publish-order",
      context,
      async () => LoadStrikeResponse.ok("200")
    );
  })
  .withLoadSimulations(
    LoadStrikeSimulation.inject(10, 1, 20)
  );

const result = await LoadStrikeRunner
  .registerScenarios(scenario)
  .withRunnerKey("rkl_your_runner_key")
  .run();

run() returns the detailed run result, including generated report files, scenario statistics, metrics, and sink status.

Trace-To-Test Autopilot

Use await LoadStrikeAutopilot.generate(...) to infer a starter plan from a captured artifact. Set Options.RunnerKey so generation can validate the Trace-To-Test Autopilot entitlement. Check result.Readiness and result.ReadinessFailures first; call result.buildScenario() only when it is LoadStrikeAutopilotReadiness.Ready, then execute the scenario through the normal runner with a valid RunnerKey.

Use SecretBindings to map redaction locations such as header:Authorization or body:$.client_secret to environment variables, TrackingSelector when the selector cannot be inferred, and EndpointBindings, AllowedReplayHosts, or BaseUrlRewrite when a replay target must be bound. Secret values are resolved when the generated scenario runs; they are not written into the generated plan. Any gate satisfied by user setup is omitted from ReadinessFailures.

Runner Keys

Runnable workloads require a RunnerKey. Supply it with .withRunnerKey(...) or through your application configuration before calling run().

Documentation

• Product documentation: https://loadstrike.com/documentation