HeyForm

Build forms and surveys and keep the answers on your own device. A conversational, block-based builder with logic jumps, file uploads, hidden fields and a results view — the kind of thing people normally rent from Typeform.

A three-container bundle: the HeyForm app, a MongoDB database and a Redis cache for background jobs, all isolated in their own Docker network. The agent generates the session key and the form encryption key on first install and keeps them on the device — Obacht never sees them.

Needs a reasonably modern CPU, which is a MongoDB requirement rather than a HeyForm one. On ARM it wants ARMv8.2-A, so a Raspberry Pi 5 works and a Pi 4 does not — its Cortex-A72 lacks the instructions, and the last MongoDB that would run there went out of support in February 2024. On x86 it wants AVX. Bare metal from about 2012 on has it, but a virtual machine only sees it when the hypervisor passes the host CPU through: on Proxmox, libvirt or QEMU set the CPU type to host rather than the default kvm64/qemu64, or MongoDB will refuse to start and the instance never turns healthy.