NovaTerminal is a modern, cross-platform terminal emulator focused on correctness, performance, and predictability — built on .NET 10, Avalonia, and a Rust-backed PTY. Same input, same output, every time.
$ git log --oneline --graph
* feat(mcp): observe toggle #298
* fix(vt): SGR italic conformance #295
* perf(skia): glyph cache warm #291
* docs: agent host direction #289
$ ▍
Terminal correctness is enforced by automated tests, not guesswork. The renderer is gated by performance contracts, the parser is measured against a conformance matrix, and replay parity prevents silent behavioral drift.
Same input → same output. Always. Enables reliable testing, replay, and bug reports you can actually reproduce.
Record terminal sessions and replay them with pixel-level consistency. When something goes wrong, you can step through it frame by frame.
Built with conformance and standards in mind — not best-effort rendering. A CI lane measures every supported VT/ANSI feature.
Smooth, modern pipeline using Skia with a snapshot-only rendering boundary and conservative perf ceilings enforced by CI.
Acyclic, focused class libraries with enforced invariants. Designed for future workflows: cloud, automation, AI-assisted tooling.
An opt-in MCP server lets Claude Code and other agents observe your live terminal sessions — and, behind a separate opt-in, drive them.
From quick REPL sessions to fullscreen TUIs, NovaTerminal keeps the same predictable behavior across operating systems.
NovaTerminal is feature-complete for everyday work, and ships with capabilities most terminals don't have — replay-driven debugging, conformance-tested VT, and an opt-in agent host.
A frame-agnostic VT/ANSI parser and cell-based buffer, measured against a conformance matrix and replay parity tests.
A modern UI for people who live in the terminal: tabs, splits, command palette, search, profiles, and live settings — no restart required.
Suggestions anchored to what the shell actually reports, not to a guess about where your prompt ends — built on OSC 133 shell-integration marks, with a one-line installer for remote hosts.
Move your setup between machines, or roll it back after something goes wrong — settings, themes, connections, workspaces, policy and snippets in one portable file.
First-class inline graphics so charts, plots, and previews land where you expect them — alongside prompts, not in a separate viewer.
Cross-platform SSH built for VT correctness and the realities of fullscreen TUIs.
NovaTerminal guarantees identical terminal behavior across Windows, Linux, and macOS. Platform-specific differences are limited to the OS surface.
NovaTerminal is organized into focused class libraries with an
acyclic dependency graph. The architecture invariants are
enforced by
NovaTerminal.Architecture.Tests at IL, csproj, and namespace level — not aspirational.
App (UI)
Avalonia window, themes, settings, orchestration
Platform
Input, paths, process, SSH — shared runtime primitives
VT
Frame-agnostic parser + cell-based buffer (zero references)
Rendering
SkiaSharp text shaping, GPU glyph cache, snapshot boundary
Pty
OS integration + PTY sessions (raw bytes only, no VT)
Replay
Deterministic session recording and playback
Enforced invariants: VT is a leaf
with zero project references;
Pty must not depend on
VT;
Replay and
Rendering reference exactly
VT; no production assembly
references test libraries.
Bytes become cells
The PTY layer delivers raw bytes from the shell. The VT parser turns them into typed cells in a frame-agnostic buffer. The renderer snapshots that buffer at frame boundaries — never more often.
Snapshots stay pixel-stable
Rendering is gated by a performance contract: same buffer state, same pixels, every time. Replay parity is a first-class test, not a best-effort log.
Conformance is enforced
A dedicated CI lane regenerates the VT/ANSI conformance report on every change and fails on regressions. Ghostty gap tracking keeps the matrix honest.
A local, stdio
Model Context Protocol
server (NovaTerminal.McpServer) exposes NovaTerminal to Claude Code, Claude Desktop, VS Code, and other MCP clients. The default surface is read-only; everything
that touches a live session is opt-in, layered, and journaled.
Read-only, offline tools. Project docs, VT/ANSI conformance data, and JSON validators for themes, SSH profiles, and settings.
Opt-in. List sessions, read screens, capture scrollback, wait for events, export replay. Screenshots have their own sub-toggle and are journaled.
A separate opt-in on top of Observe. Send input, spawn, and close sessions. SSH targets require a per-profile allowlist. Every call — allowed or denied — is journaled in-app.
Build the server first, then point your MCP client at the compiled
DLL — never dotnet run, which corrupts the stdio stream.
# Build
scripts/build.ps1 build -c Release src/NovaTerminal.McpServer
# Register with Claude Code
claude mcp add novaterminal -- \
dotnet "<path-to-repo>/src/NovaTerminal.McpServer/bin/Release/net10.0/NovaTerminal.McpServer.dll"
For Claude Desktop or VS Code, add the same
command/args to the client's MCP config.
Windows and macOS have one-click installers that keep themselves up to
date — a new version downloads in the background and applies on your next
restart. Linux ships a self-updating AppImage, a system
.deb, and a portable tarball, for
x64 and
arm64 alike. Every release runs the gating unit-test lane on all three OSes before any bundle is published. Replace <tag> with the version you downloaded.
macOS builds are signed and notarized (since v0.7.0), so Gatekeeper opens them normally. Windows installers are not code-signed yet, so SmartScreen will warn on first run — choose More info → Run anyway; see issue #91 .
Native AOT, self-contained. Download from the latest release .
Installer — recommended
NovaTerminal-Setup-win-x64-<tag>.exe
Per-user install — no admin prompt. Adds Start Menu and Desktop shortcuts, and updates itself in the background.
Portable — no updater
NovaTerminal-win-x64-<tag>.zip
winget install benyblack.NovaTerminalNative AOT, self-contained. Download from the latest release .
Installer — recommended
NovaTerminal-Setup-osx-arm64-<tag>.pkg
Installs a proper NovaTerminal.app bundle, and updates itself in the background. Signed and notarized since v0.7.0, so Gatekeeper opens it with no warnings.
Portable — no updater
NovaTerminal-osx-arm64-<tag>.zip
unzip NovaTerminal-osx-arm64-<tag>.zip
open NovaTerminal.appNative AOT, self-contained. Download from the latest release .
AppImage — recommended
NovaTerminal-linux-<x64|arm64>-<tag>.AppImage
Self-updating, like the Windows and macOS installers. Needs glibc 2.35+ (Ubuntu 22.04+, Debian 12+, Fedora 36+). Ubuntu 22.04+/Debian 12 ship no FUSE 2 — install it (sudo apt install fuse) or launch with --appimage-extract-and-run.
chmod +x NovaTerminal-linux-<x64|arm64>-<tag>.AppImage
./NovaTerminal-linux-<x64|arm64>-<tag>.AppImageOr the .deb — system integration
novaterminal_<version>-1_<amd64|arm64>.deb
sudo apt install ./<exact .deb filename from the release page>The .deb adds a desktop entry, icons, the nova command on your PATH, and a man page. It does not update itself: there is no APT repository yet, so apt upgrade will not see new releases — download and reinstall each one. Its filename carries both the version and the architecture and changes every release — copy the exact one for your machine (amd64 or arm64) from the release page. A portable .tar.gz is there too.
Prerequisites
.NET 10 SDK and a stable Rust toolchain. On macOS, install Xcode Command Line Tools. On Windows, MSVC build tools.
dotnet --version # expect 10.x
rustc --version # expect stable
cargo --versionBuild
dotnet restore triggers a cargo build for the native PTY and SSH libraries automatically.
dotnet restore
dotnet build -c ReleaseTest
Run the same filter as the blocking CI unit lane (fast, deterministic).
dotnet test -c Release --no-build \
--filter "Category!=Replay&Category!=RenderMetrics&Category!=PtySmoke&Category!=Stress&Category!=GoldenSharedPng"NovaTerminal has a strong correctness culture — terminal core invariants are enforced and automated tests gate changes. If you care about that, you'll feel at home here.
A session-facing MCP surface so AI agents can observe, query status of, and — with explicit, separate permission — act inside live terminal sessions. Threat model and direction are public.
Every supported VT/ANSI feature is tracked in a matrix; a dedicated CI lane regenerates the report and fails on regressions. Ghostty gap tracking keeps the matrix honest.
Cross-platform SSH client (experimental, opt-in) with VT correctness, resize coalescing, dynamic forwarding, keepalive, and runtime password memory.
Snapshot-only rendering boundary, replay parity, seam safety under fractional DPI, and conservative perf ceilings enforced by CI.
NovaTerminal splits tests into focused, deterministic lanes. The blocking CI lane is fast and runs on every PR; the long-running lanes (replay parity, render metrics, golden PNG) run on schedule.
See CONTRIBUTING.md for the workflow and docs/reviews for periodic deep code reviews with the current known-issues backlog.