The Linux of game engines. Open source. AI-first. Cross-platform. Built by AI, maintained by AI, for AI agents and human developers — together.
Every game engine ever built assumed a human developer sat at a keyboard. Nexus is the first one that doesn't.
A solo developer with AI should ship a AAA game in a weekend. A small team should ship a Dota-complexity game in months. Fans should extend the best games of all time within days of release. The barrier between idea and shipped multiplayer game should be measured in token budget, not man-years.
That is the design target. Every line of every spec is judged against it.
| Layer | What it is |
|---|---|
| 🎮 nexus-engine | The core. ECS · renderer · physics · audio · networking · scripting · assets · editor. 100M LOC at maturity. |
| 🛠 nexus-cli | nexus new mygame — Rails-style scaffolding. Convention over configuration, ejectable. |
| 🤖 nexus-coder | In-house AI coding agent. Vercel AI SDK + OpenRouter. Massively parallel. Model-swappable mid-project. |
| 🧪 nexus-agent-sdk | The headless API every AI dev tool executes against. Telemetry · scenarios · snapshots · replay. |
| 🔌 nexus-mcp-server | Model Context Protocol server wrapping the agent RPC. One server, every MCP host (Claude Desktop · Claude Code · Cursor · Zed · ChatGPT Desktop · browser). |
| 🎨 nexus-assets | One command finds, generates, validates, imports. Meshy · Scenario · FLUX local · Kenney · Poly Haven. |
| 🔀 nexus-merge | AI maintainer. Reviews every PR. No politics. No burnout. No bus factor. |
| 📦 nexus-game-template | The monorepo every game starts from. Game · server · web · mobile · DLC · mods · ai-agents. |
| 🦀 nexus-crates ecosystem | The Rust-native compile-time extension layer (genres, styles, physics, netcode, telemetry sinks, asset sources, …). → docs/specs/crates/overview.md |
| 🛰 nexus-hub | Federated index + curation + verification layer over crates.io / mod marketplaces / asset libraries. JSON-first. Self-hostable. → docs/specs/hub/overview.md |
Editor scope. The native editor is narrow on purpose: asset/level quick-load, place/transform, scene tree + inspector, replay scrubber, telemetry overlays. Not a code editor. Every editor button = one agent RPC. The editor is a fast human cursor over the AI's keyboard.
# install
curl -fsSL https://nexus-engine.dev/install.sh | bash
# scaffold a new game
nexus new mygame --genre fps --style npr
cd mygame
# run with hot reload
nexus dev
# let an AI subagent build a feature for you
nexus coder implement docs/specs/genres/fps.md#weapon-system
# ship it
nexus release --to steam,itch,webEvery system in Nexus satisfies the AI-First Mandate:
| ✓ | Capability |
|---|---|
| ✅ | Machine-readable errors — every error is structured JSON with code, location, suggested_fix |
| ✅ | Telemetry by default — every system streams structured events per frame |
| ✅ | Headless operation — every system runs without a display, deterministic replay |
| ✅ | Serializable state — full game state captureable and patchable at any frame |
| ✅ | Semantic APIs — engine.spawn("dragon near castle") is a valid call |
| ✅ | Documented contracts — every public API has a machine-readable shape |
Every Nexus game is moddable to total-conversion depth by default. Cosmetic mods are zero-friction. Gameplay mods get capability prompts. Total conversions are first-class. The engine takes zero cut of any creator economy. Skyrim · DotA · GMod · Factorio · Minecraft modpacks — all of it, supported.
| Platform | Status |
|---|---|
| 🐧 Linux | v1.0 — primary dev platform |
| 🪟 Windows | v1.0 |
| 🍎 macOS | v1.0 |
| 🤖 Android | v1.0 |
| 📱 iOS | v1.0 |
| 🌐 Web (WASM + WebGPU) | v1.0 |
| 🎮 Switch / PS5 / Xbox | v1.1 (best-effort, NDA-gated) |
| 🥽 VR (OpenXR) | v1.1 |
Nexus is spec-driven — no code is written until its spec exists. The complete spec tree lives in docs/.
- 📜 Vision — the constitution
- 🧭 docs/README.md — entrypoint by role (new contributor · AI dev · game dev · modder · maintainer)
- 🗂 docs/INDEX.md — flat index of every doc
- 🧷 docs/INTEGRATION-REPORT.md — post-32-agent integration state (conflicts resolved, decisions open, what's safe to start on)
- 🧪 Solved-problems catalog (voxel · falling-sand · 2.5D · massive RTS · seamless world · destruction · weather · procgen · sim · rhythm · text-heavy · 4X · heavy particles) →
docs/architecture/08-compose-dont-build.md - 🏛 Architecture — system map · principles · tech stack · ADRs
- 🔧 Specs — every subsystem, AI dev teams execute against these
- 🤝 Contracts — exact boundaries between systems
- 🎯 Genre modules — fps · rpg · rts · moba · platformer · racing · ...
- 🛠 Guides — coding style · testing · deploy · release · liveops · modding · PR workflow
The repo ships a complete .claude/ orchestration layer.
| Path | Purpose |
|---|---|
🧠 CLAUDE.md |
Mastermind orchestrator — read first |
🎭 .claude/agents/ |
118 specialist subagents (architect · network-engineer · rollback-specialist · crash-triager · mcp-server-engineer · ide-extension-engineer · editor-rpc-parity-auditor · mod-author · mod-curator · nexus-hub-operator · ...) |
⚡ .claude/commands/ |
Project slash commands (/spec /contract /impl /scenario /bench /triage /review /parallel) |
🔧 .claude/skills/ |
PR-workflow skills (open-pr / wait-for-ci / babysit-pr / coderabbit-triage / coderabbit-resolve) |
🐰 .coderabbit.yaml |
CodeRabbit config tuned for Nexus principles |
📜 scripts/ |
Tested, parameterized CLIs designed for agents to read · execute · trust |
The default expectation: dozens of subagents in flight, in parallel, all the time. The dev orchestrates; the agents work; the reviewers gate.
Humans and AI agents follow the same process. Read docs/guides/contribution.md and docs/guides/ai-dev-onboarding.md.
The TL;DR:
- Read
docs/initial/vision.md(the constitution). - Read
docs/architecture/01-principles.md(the 15 binding laws). - Find or write the spec for what you're changing.
- Write tests first.
- Implement.
- Open PR — the merge-bot reviews on technical merit alone.
MIT. Forever. No dual licensing. No open core. No "community edition" with a paid pro tier. The entire engine, every module, every tool — MIT. Why.
Nexus will never:
- ❌ Charge royalties
- ❌ Introduce a paid tier
- ❌ Change the license
- ❌ Be acquired and closed
- ❌ Have a single human maintainer as a point of failure
Nexus will always:
- ✅ Be MIT
- ✅ Be fully open source
- ✅ Run on every major platform
- ✅ Treat AI agents as first-class users
- ✅ Accept contributions on technical merit alone
- ✅ Ship working software over perfect architecture
Built by AI. Maintained by AI. For everyone who ever wanted to ship a game. 🚀