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Pixnop edited this page Jul 11, 2026 · 9 revisions

Atlas

Atlas is an in-process integration-test harness for Vintage Story mods. It boots a real, headless Vintage Story server inside your dotnet test process, drives it tick by tick, and lets you write deterministic scenarios in plain C# with xUnit.

Atlas is generic: any Vintage Story mod is testable, with no dependency on any particular mod.

Current version: v0.7.0, published on NuGet. This release completes the world-isolation trilogy: FreshWorld = true boots a brand-new world on a recycled host, RollbackWorld = true restores the same world in place roughly 25x faster (now with visible degrades, a per-class isolation summary and an opt-in StrictIsolation mode), and the new RestartWorld = true restarts the server for real and carries the world over, for scenarios asserting on what actually persists. Also new: atlas fixture (builds the .vcdbs world fixtures [AtlasWorld(SaveFile = ...)] boots against, from an ordinary builder scenario), IWorldSession.PlaceSchematic (prebuilt structures in one line) and atlas --version. Earlier releases added multi-process parallel execution (atlas run --parallel), the machine-readable worker mode (--worker, JSONL events), the atlas CLI itself, pre-boot data file seeding ([AtlasDataFiles]), and prebuilt world saves. See the changelog for the full history.

15-line example

using Atlas.Api;
using Atlas.XUnit;
using Vintagestory.API.MathTools;
using Xunit;

public class MarkerScenarios : AtlasScenarioBase
{
    [AtlasScenario]
    public async Task Chest_Should_BePlaceable_When_WorldIsReady()
    {
        BlockPos pos = World.Spawn.Offset(1, 1, 0);
        World.SetBlock("game:chest-east", pos);
        await World.Ticks(5);
        Assert.Equal("game:chest-east", World.BlockAt(pos).Code.ToString());
    }
}

Run it with dotnet test. No client, no window, no manual server setup.

Documentation

Page Covers
Getting Started Requirements, quickstart, first scenario, run
Writing Scenarios Attribute reference, time model, the world-isolation trilogy (fresh, rollback, restart), world fixtures and schematics, data file seeding, dimensions, test players, command results, the Api escape hatch
Mod Staging Folder/zip/dll staging, AtlasMods, the MSBuild AtlasMod sugar
CLI The atlas run reference, filtering and listing, worker mode and the JSONL protocol, multi-process --parallel execution, authoring world fixtures with atlas fixture
Architecture The three layers, the game-thread pump, the bridge rendezvous
CI Recipes GitHub Actions recipe, version matrix, TRX output, parallel execution
Compatibility Supported Vintage Story versions, the weekly sweep
Troubleshooting Common exceptions and how to resolve them
Roadmap Open issues and what's next

Community

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