Focused Tool · Apache 2.0 · Single Binary · Developer Tools

Self-hosted API contract tester

Define expected request and response shapes, run them against your API on a schedule, alert when the contract breaks. Catches breaking changes before your users do.

Install Assay II Free Complete — all 164+ tools — 14-day free trial
The case for owning your data

Every contract your team creates contains context that matters — name, endpoint, method, expected status, expected body. When that data lives in a third-party service, you are one acquisition or policy change away from losing access. Assay II keeps it local.

Replaces Pact broker ($300/mo).

Define expected request and response shapes, run them against your API on a schedule, alert when the contract breaks. Catches breaking changes before your users do. Your data lives in a SQLite file on your disk that you can back up by copying a folder, move to another machine, or query directly with any SQLite tool. The binary keeps running if Stockyard disappears tomorrow, because it is Apache 2.0 and you have a copy.

Quickstart

Running in under a minute.

Stockyard runs on desktops and laptops. To install, open this page on your Mac, Windows, or Linux computer.

After install, open http://localhost:9980 in your browser.

Advanced: install via terminal instead
curl -fsSL https://stockyard.dev/install.sh | sh -s -- --tool assay2

Single binary. Embedded SQLite. No Docker. No database. No dependencies.

Pricing

14 days free. Pro when you need it.

Free
$0
forever
  • 5 contracts
  • Single binary, embedded SQLite
  • Apache 2.0 — modify freely
Pro
$7.99
per month
  • Unlimited contracts, CI integration, diff reports, schema versioning
  • License key, no cloud dependency
  • Email support

License key by email. One env var.

Your license key arrives by email within 5 minutes of checkout. Set it as an environment variable and restart the binary.

export STOCKYARD_LICENSE_KEY=SY-xxxxxxxxxxxxxxxxxxxx
./assay2

No cloud connectivity required. The binary validates the key offline with Ed25519 signatures.

Part of the Stockyard family — 164 self-hosted tools · Complete bundle — 14-day free trial · stockyard.dev