PreScale

Launch-readiness load testing for developers — find what breaks before your users do.

Point it at a URL. It ramps real traffic until something gives, then tells you, in plain English, what failed first, at what load — and why.

pip install prescale
prescale run https://staging.myapp.com

Scale readiness: ⚠️  Survives ~90 (75–110) concurrent users
First failure   errors climb at ~150 users
Likely cause    Server returned 5xx under load — likely a DB connection pool.

It isn't a framework you program (like k6 or Locust) — there's nothing to script. Point it, get an answer, fix, repeat.

Commands

• prescale run <url> — ramp traffic; what breaks first and at what load, with a confidence band.
• prescale investigate <url> — probe the culprit route to explain why it breaks and how to fix it. Local, deterministic, no LLM.
• prescale audit <url> — load-free HTTP hygiene check (compression, caching, CDN, HTTP/2).
• prescale compare — capacity diff of two runs; --fail-under / --fail-on-regression for CI gating.
• prescale run --profile product-hunt — frame the verdict as a launch scenario ("would survive a Product Hunt #1 launch").
• prescale history / show / schema — saved runs and their versioned JSON contract.
• prescale mcp — run as an MCP server so a coding agent can load-test mid-build (pip install 'prescale[mcp]').

Why

• Zero config — no test scripts, no account; one command against a URL.
• Stack-agnostic — Vercel, Fly, Railway, a VPS, serverless… it just needs a URL.
• An answer, not a histogram — "you're good to ~90 users, your DB is the wall," and how to fix it.
• Safe by default — won't hammer a non-local host until you confirm you own it.

Requires Python 3.10+. Full docs, examples, and source: https://github.com/pyjeebz/PreScale

License

Apache 2.0 — find what breaks before your users do.