Make the FIPS core build and run as an embedded Android library. The host app owns the TUN (e.g. an Android VpnService) and FIPS performs no system-TUN or CAP_NET_ADMIN operations. Squashed from the following changes: - gate desktop transports/TUN by target_os, not features: a plain `cargo build` now compiles for every target with no flags. Ethernet (raw AF_PACKET / BPF) is gated to linux/macos, so Android (target_os = "android", not "linux") self-excludes it as Windows already did; real system-TUN ops are gated per linux/macos and Android gets a no-op stub; the ipi6_ifindex cast handles it being i32 on Android vs u32 on macOS. No Cargo features are introduced; desktop builds are unchanged. - app-owned TUN seam: Node::enable_app_owned_tun() lets an embedder that owns the TUN fd exchange IPv6 packet bytes with FIPS over channels instead of FIPS creating a system TUN device. It returns (app_outbound_tx, app_inbound_rx): the embedder pushes packets read from its fd into the outbound sender (app -> mesh) and pulls packets destined for its fd from the inbound receiver (mesh -> app). start() gates system-TUN creation on tun_tx being unset, so with the channels pre-installed it skips device creation and does no system-TUN ops; both directions reuse the existing inbound-shim and run_rx_loop wiring. Packets entering via app_outbound_tx bypass handle_tun_packet, so the embedder must push only fd00::/8-destined packets and clamp TCP MSS on outbound SYNs; the rustdoc and the IPv6-adapter design doc spell this out. - keep the android target warning-clean so the cross-compile check passes clippy -D warnings. - add an Android cross-compile CI check: cross-compile the library for aarch64-linux-android via cargo-ndk and run clippy -D warnings. Android ships as an embedded library (the host app owns the TUN), so there is no daemon binary to package; this is a check job, not a packaging one. - docs: list Android as a supported platform. Tests: app_owned_tun_seam_wires_channels covers the channel round-trip and the Active state; start_skips_system_tun_when_app_owned runs start() and asserts no named system device is created.
FIPS Documentation
FIPS (Free Internetworking Peering System) is a self-organizing encrypted mesh network built on Nostr identities, capable of operating over arbitrary transports — local networks, the public internet, Tor, Bluetooth, or point-to-point links — without central infrastructure.
With FIPS, your machine becomes a node in the mesh with a self-generated cryptographic identity. There are two ways to deploy it.
As an overlay on top of existing IP networks, FIPS lets your node reach any other FIPS node wherever it sits — behind a NAT, on a different ISP, on a phone over cellular, on a laptop with only Bluetooth in range, or behind a Tor onion. The mesh forwards IPv6 traffic transparently and end-to-end encrypted, with no central VPN concentrator or coordinating server.
From the ground up over raw Ethernet, WiFi, or Bluetooth, FIPS provides a complete permissionless network without any pre-existing IP infrastructure, ISP, or DNS. Any node that joins the link gets routable IPv6 addresses, peer discovery, and a path to every other node automatically.
Either way, existing networking software runs over it unchanged: SSH, HTTP servers, file transfer, anything IPv6-native works the same way it would on a local network.
New to FIPS? Start with the Getting Started guide.
Documentation Sections
Tutorials
If you are starting from scratch and want a guided path to a working mesh, go here.
How-To Guides
If you have a specific task in mind — enabling a feature, deploying a component, diagnosing a problem — go here.
Reference
If you need to look up wire formats, configuration keys, command flags, or counter inventories, go here.
Design
If you want to understand how the mesh self-organizes, why FIPS makes the choices it does, or how the pieces fit together, go here.