aisp-emu (Ai Sp@ce Server Emulator)

aisp-emu is a fan-made server emulator for the discontinued Japanese MMO Ai Sp@ce. The goal of this project is to recreate the original experience for educational purposes and to keep the game playable after its shutdown.

Test server running at https://aisp.moe/ Instructions on connecting are on the site

Project scope

• Provides a replacement server stack for AISp@ce, implemented in .NET 10.0 with Entity Framework Core and NLog for persistence and logging.
• Serves as a learning resource for networking, game server architecture, and reverse engineering of legacy online games.
• Does not ship original game assets. For game data and metadata about AISp@ce itself, refer to the community-maintained archive at Tricon2-Elf/AI-Space.

Repository layout

• aisp.Network/ — Wire format, TCP transport, and client-compatible encryption (no game logic or database code).
• aisp.Common/ — Game logic, packet handlers, and Entity Framework Core persistence; references aisp.Network.
• aisp.Server/ — Executable host; runs Auth, Msg, and Area servers in one process. Includes runtime configuration such as appsettings.json and NLog.config.
• tests/aisp.Network.Tests/, tests/aisp.Common.Tests/, tests/aisp.Server.Tests/ — xUnit test projects for each layer.

Dependency order: aisp.Network → aisp.Common → aisp.Server.

Prerequisites

• .NET 10 SDK for building and running the server projects.
• Access to AISp@ce client metadata and information; see the AI-Space archive for historical game metadata.

Building

From the repository root:

dotnet restore
dotnet build

This restores NuGet dependencies and compiles all projects in the solution.

Testing

Run the full test suite from the repository root:

dotnet test aisp.sln

Run tests for a single project:

dotnet test aisp.Common.Tests
dotnet test aisp.Network.Tests
dotnet test aisp.Server.Tests

Tests use xUnit v3 with in-memory SQLite for database integration tests. See AGENTS.md for more detail on test conventions and helpers.

Running the server

After building, start the server project:

dotnet run --project aisp.Server

Configuration files such as appsettings.json and NLog.config are copied to the output directory during build. Adjust database providers or logging behavior there before launching.

Contributing

Community contributions are welcome. Please ensure changes respect the educational, non-commercial nature of the project. If you contribute reverse-engineered insights or packet captures, avoid including any proprietary assets.

Disclaimer

This emulator is an unofficial, community effort provided for educational and preservation purposes. It is not affiliated with the original AISp@ce developers or publishers.

AI-Assisted Development

This project makes use of AI-assisted development tools to help accelerate certain tasks. This choice is driven by limited development time and other constraints that make traditional pacing difficult. AI assistance allows the project to maintain momentum despite these challenges.

All AI-assisted code is reviewed, tested, and verified before being committed and all responsibility of said code is owned by the author and not the LLM No code reaches the repository without human oversight. The use of AI is strictly assistive — it does not replace manual code review, testing, or architectural decision-making.