Get Esper on every machine you own.
Native installers for Windows and macOS, packages for every major Linux distribution, and updates through your own package manager. No account to create before the download button works.
Build it, run it.
Esper is in early development, and there are no release builds yet. For now the way in is building from source. Installers and packages for every platform are coming. Esper never checks in with anyone. Update alerts are there if you want them, off until you turn them on, and even then it's one anonymous request that fetches a version number and nothing more.
Rolling it out to a fleet? A silent-install MSI is on the releases page too.
Build it from source
Prefer to read the code before you trust it? It's all there. Clone it, build it, and check for yourself that nothing calls home.
Trust the math, not the mirror.
Every release ships with signed checksums. Wherever your download came from, thirty seconds proves it is byte-for-byte the release we built.
Every release is signed with minisign. Verify against the public key pinned in the README. Reproducible builds are used wherever the platform makes them achievable, so you can also build from source and compare.