farsee

Apache-2.0 C11 RFB/VNC + RDP client that draws the remote desktop in a Kitty graphics terminal.

This is not Apple High Performance Screen Sharing (AHPSS). Classic VNC Authentication proves password knowledge only — it is not session encryption. See SECURITY.md.

Install / run

nix run github:zw3rk/farsee -- --version
nix run github:zw3rk/farsee -- vnc://host.example:5900
nix run github:zw3rk/farsee -- rdp://user@host.example

Password is never taken from argv or a URL. Use the TTY prompt (echo off) or --password-fd N. Production rejects URL userinfo passwords.

Terminals (Kitty graphics)

Live graphics use the Kitty graphics protocol (KGP). Use --presenter null when the client must receive frames without displaying them.

Terminals that implement KGP (per the protocol docs; feature depth varies):

Terminal	Notes
Kitty	Reference implementation
Ghostty
WezTerm
Konsole
Warp
iTerm2
wayst
st	With the KGP patch
xterm.js	Embeddable / web

Farsee is developed and manually accepted primarily against Kitty. Other entries may work for basic placement; SHM transfer, APC drain timing, and cursor overlay can differ. Nested multiplexers (tmux, screen) often need passthrough configuration.

Develop

nix develop
make help
make test
make ci

Hermetic toolchain via the flake (flake.nix); all work goes through the Makefile (make help).

Common targets

Target	What it does
make help	Full target catalogue
make / make build	Dev build (Clang, strict warnings)
make test	Build and run the unit suite
make ci	Full release-candidate gate
make asan-ubsan	Address + UBSan build and tests
make release	Optimized release binary
make no-rdp-release-check	Optimized release gates without FreeRDP
make check-reproducible	Reproduce and compare complete artifacts
make coverage / make coverage-report	Coverage build + report
make fuzz-smoke	Brief corpus run per fuzz target
make check-license	SPDX + third-party notices
make clean	Remove build outputs

The build and test matrix supports macOS and Linux. Published release artifacts are currently limited to aarch64-darwin and x86_64-darwin by release/dependencies.json. Linux release packaging fails closed because its runtime libraries are not approved by the locked release-license policy.

Scope

• Classic VNC (RFB 3.3/3.7/3.8): VNC Auth, Raw / CopyRect / ZRLE, Cursor, DesktopSize, input, clipboard, Bell
• Apple Screen Sharing: security types 33 and 36 are live. The default policy prefers 33; --apple-security=36 requires 36. These features are present in the retained implementation but are not approved for release; see ADR-0013.
• Apple encodings: 0x03f3 supported type-0 image planes paint; 0x0450 decodes to a separate RGBA8 alpha cursor and composites into the copied presentation frame.
• RDP via FreeRDP
• Live graphics need a KGP-capable terminal

Known limitations

No VNC TLS/VeNCrypt. The default Apple post-auth mode is the cleartext compatibility path; protected records and the private Apple encoding list are explicit options. Apple 0x0450 supports the profile-1000 cursor; other profiles fail closed. Details: docs/known-limitations.md.

Documentation

Doc	Role
USAGE.md	CLI, flags, runtime paths
plan.md	Controlling requirements
docs/implementation-status.md	Gate status
SECURITY.md	Secure-use guide
THIRD_PARTY_NOTICES.md	Dependencies & licenses

License

Apache-2.0 — see LICENSE. Source and dependency rules are in ADR-0001. ADR-0013 and docs/provenance.md record the separate Apple feature release block.