API Load Tester

Overview

This skill generates realistic load test scripts from API definitions and executes them with proper ramp-up patterns, authentication flows, and assertions. It produces clear reports identifying breaking points, bottlenecks, and latency percentiles at each traffic level.

Instructions

Step 1: Choose Tool and Gather API Info

Prefer k6 for complex scenarios (multi-step flows, thresholds, custom metrics). Use wrk for quick single-endpoint benchmarks. Use autocannon if only Node.js is available.

• k6: the current release is v2.3.0 (v2.0.0 shipped 2026-05-11). Scripts written for v1 mostly still run, but v2 removed old commands: write k6 cloud run script.js (the k6 cloud script.js form is gone), use --summary-mode=disabled instead of --no-summary, and drop executor: externally-controlled along with k6 pause, resume, scale and status. Use ramping-vus or constant-arrival-rate instead.
• autocannon (8.0.0): a Node.js benchmark with -c for connections and -d for duration in seconds. Example: npx autocannon@8.0.0 -c 100 -d 60 "https://api.brightcart.io/api/search?q=laptop&page=1".
• wrk: install it from your OS package manager (brew install wrk or apt install wrk). It is single-endpoint only and has no scripted multi-step flows without Lua. Its current release was not checked for this skill.