Summary: Foundation Devices is an open-hardware Bitcoin signer stack built around Passport plus Envoy. The point is the combined signer-and-companion setup — airgapped signing, firmware trust, Tor and own-node defaults, and mobile coordination — not a generic hardware-wallet storefront.
What it does:
Builds Passport Core and Passport Prime Bitcoin hardware wallets for offline signing and long-term self-custody
Uses camera- and microSD-based airgapped communication rather than USB data, Bluetooth, or other wireless data paths on Passport Core
Ships Envoy, a cross-platform mobile Bitcoin wallet and Passport companion app for setup, account management, firmware updates, transaction handling, Tor connectivity, and own-node connectivity
Publishes open-source firmware, hardware design files, companion-app code, and related KeyOS / library work through its public GitHub organization
Documents security checks, supply-chain-tamper verification, animated QR signing flows, and reproducible-source expectations as part of the public product surface
Key claims:
The Passport Core product page says Passport Core has no direct connection with the outside world and instead uses a camera and QR codes for communication, which is the clearest top-level framing for the device’s security model
The same product page explicitly says both Passport Core software and hardware are fully open source, which makes the project stand out from partially open or closed hardware-wallet vendors
The official docs position Passport Core as Foundation’s “next generation hardware wallet for keeping your bitcoin safe and secure,” while separate Envoy docs position Envoy as both a mobile wallet and a Passport companion app rather than a thin configuration utility
The Envoy product page is especially useful for categorization because it exposes Magic Backups, Tor connectivity, own-node connectivity, Passport onboarding and firmware updates, and a cross-platform Flutter-plus-Rust architecture, which makes the overall stack broader than a single hardware signer
The Passport firmware repository highlights secure bootloader / firmware separation, reproducible-build guidance, and explicit use of open-source upstream components such as MicroPython and Trezor crypto libraries
The Passport hardware repository publishes PCB, enclosure, and bill-of-materials files, which reinforces that Foundation’s open-source claim extends into hardware design rather than stopping at app code
The GitHub organization also surfaces Envoy, Passport firmware, Passport hardware, KeyOS, and other internal libraries, which makes the company look like a coherent Bitcoin self-custody platform rather than a single-device storefront
Whitepaper: No canonical Foundation Devices whitepaper or litepaper surfaced in this pass. The clearest current source of truth is the official Passport and Envoy product pages, Foundation’s docs portal, and the public Passport firmware / hardware / Envoy repositories; see ../whitepapers/foundation-devices-primary-sources-2026-05-01.md.
Reusable lens: this is useful when a hardware wallet is really a signer-plus-companion-wallet stack with meaningful routing, firmware-trust, and own-node defaults.