The APIFae manual

APIFae replaces the API you depend on with one you control — locally and in CI — and keeps that stand-in honest as the real API changes.

That second half is the point. Most mocking tools solve the first-day problem and then rot: the mock is written once, the real API moves, and the tests keep passing against a fiction. APIFae treats drift as the core problem rather than an afterthought, which is why diff and patch exist alongside the mock server.

It is a single native binary. There is no runtime to install first.

Start here

If you want to	Read
Get a mock serving in the next few minutes	Getting started
Build against an API that does not exist yet	Mock an API before it exists
Catch the real API drifting away from your mocks	Keep a mock honest
Run that check in GitHub Actions	Check drift in CI
Capture a real API and replay it	Record and replay
Know what a recording keeps of your credentials	Secrets and redaction
Know what a command is for	Commands
Look up a flag, a default or an exit code	Reference
Know whether it can do the thing you need	FAQ
Fix an error you just hit	Troubleshooting

What works today

Twelve commands do real work: init, up, serve, validate, status, diff, patch, record, ca, scenario, config and report. Everything in this manual is written against those.

Four more — login, logout, push and pull — name a hosted service that does not exist yet. They exit non-zero with a message saying so rather than pretending to have worked. Nothing in the local workflow needs an account; see Commands that refuse.

Sharing a workspace with your team today means committing it to git.

Install

APIFae is distributed as a single binary for macOS, Linux and Windows.

macOS and Linux

curl -fsSL https://apifae.com/install.sh | sh

Homebrew

brew install apifae/tap/apifae

Windows, with Scoop

scoop bucket add apifae https://github.com/apifae/scoop-bucket
scoop install apifae

npm, if you would rather pin it per project than per machine:

npm install --global apifae

Then check it:

$ apifae --version
EXIT: 0

What has actually been verified

Publishing a channel and proving it installs are different claims, and APIFae keeps them apart deliberately.

Every channel above is published by a green release pipeline. Rather fewer have been installed and run on every operating system they reach, and some combinations nobody has tried at all. So try the one you need early rather than reading the list above as uniform coverage — and if it does not work, open an issue. An untried combination is exactly the one worth hearing about.

The CLI as a container image

ghcr.io/apifae/cli is a multi-arch image (linux/amd64 and linux/arm64) carrying the same binary — not a fifth entry in the list above, because pulling it does not put apifae on your PATH the way the four channels above do. It exists for validate and diff in CI and in a pre-commit hook, where "run this without installing anything but Docker" is the point:

$ docker run --rm -v "$PWD":/work ghcr.io/apifae/cli validate

It is not built for up: the image sets no host of its own, so a server started inside it is reachable from outside the container only if the mounted workspace's own config binds 0.0.0.0. See Check drift in CI for the pre-commit hook that runs this image directly.