Andriysvyryd Unicornhack Unicornhack

UnicornHack Diagnostic Client

A headless MCP server that connects to a running UnicornHack.Web instance, mirrors the player's game state, and exposes:

• Read tools that return compact text snapshots of the current state (status line, ASCII map, actor/item/ability tables, log-since-tick).
• Action tools that submit every ActorActionType to the server and wait for the resulting per-turn change sets before returning.
• Dialog/description tools that wrap ShowDialog, QueryStaticDescription, and SendMessage.

The client maintains the canonical state itself by applying the initial GetState snapshot and subsequent ReceiveChangeSets messages, so every tool reads from one consistent mirror.

Source: test/UnicornHack.DiagnosticClient/

Prerequisites

1. SQL Server LocalDB must be installed and reachable at (localdb)\mssqllocaldb. The connection string is in src/UnicornHack.Web/appsettings.Development.json.
2. The ASP.NET Core HTTPS dev certificate must be trusted (or pass --insecure to the diagnostic client). One-time setup:

   dotnet dev-certs https --trust
   

3. The UnicornHack.Web server must be running locally (default https://localhost:7251) — see Running the Web server below.

Running the Web server

The Web project targets a release Microsoft.NETCore.App 10.0 framework. Use the system .NET install (C:\Program Files\dotnet on Windows)

In a clean PowerShell session (NOT a Developer Command Prompt rooted in another repo):

cd D:\repos\UnicornHack\UnicornHack
$env:DOTNET_ROOT = 'C:\Program Files\dotnet'
dotnet run --project src/UnicornHack.Web/UnicornHack.Web.csproj --launch-profile UnicornHack.Web

The --launch-profile defaults are in src/UnicornHack.Web/Properties/launchSettings.json — HTTPS on 7251, HTTP on 5251, ASPNETCORE_ENVIRONMENT=Development.

To run it detached (so subsequent shell commands aren't blocked):

$env:DOTNET_ROOT = 'C:\Program Files\dotnet'
Start-Process -FilePath 'C:\Program Files\dotnet\dotnet.exe' `
  -ArgumentList @('run','--project','D:\repos\UnicornHack\UnicornHack\src\UnicornHack.Web\UnicornHack.Web.csproj','--launch-profile','UnicornHack.Web') `
  -WorkingDirectory 'D:\repos\UnicornHack\UnicornHack' `
  -RedirectStandardOutput 'D:\repos\UnicornHack\UnicornHack\web.out.log' `
  -RedirectStandardError  'D:\repos\UnicornHack\UnicornHack\web.err.log'
# Tail logs to see startup messages
Get-Content D:\repos\UnicornHack\UnicornHack\web.out.log -Wait

Wait for Now listening on: https://localhost:7251 in the log before connecting clients. The Razor home page (/) currently throws No service for type 'Microsoft.ApplicationInsights.AspNetCore.JavaScriptSnippet' has been registered — this is harmless to the SignalR hub (/gameHub), which is what the diagnostic client uses.

Debug / development server options

The server reads four optional configuration keys at startup. They are CLI parameters routed through ASP.NET Core's default AddCommandLine provider — there is no appsettings.json block for them. Three are bound to UnicornHack.GameOptions (which is then persisted with the saved game); the fourth, ResetDatabase, is a one-shot startup flag read directly by Program.cs.

Examples:

# Deterministic dev session that resets the DB:
dotnet run --project src/UnicornHack.Web -- --InitialSeed=1 --ResetDatabase=true

# Production-shaped run (random seed, no resets):
dotnet run --project src/UnicornHack.Web

# Same via environment variables (when CLI args are awkward, e.g. systemd):
$env:InitialSeed=1; dotnet run --project src/UnicornHack.Web

The repo's launchSettings.json ships with no commandLineArgs defaults, so the UnicornHack.Web launch profile gives you a production-like run (random seed, no reveal, no reset). Append the flags above on the CLI.

Launch

From VS Code (Copilot MCP)

The repo ships a workspace MCP server definition at UnicornHack/.vscode/mcp.json. VS Code auto-discovers it. To use it:

1. Make sure the UnicornHack.Web server is running (see Prerequisites).
2. Open the Chat panel → tools picker → enable unicornhack-diagnostic (or MCP: List Servers → Start).
3. VS Code will prompt for playerName and serverUrl the first time; defaults are diag-bot and https://localhost:7251.

The server starts via dotnet run --project test/UnicornHack.DiagnosticClient with --insecure and a log file under that project's bin/ folder. Once started, all read/action/dialog tools listed below are available to Copilot.

From the command line

dotnet run --project UnicornHack/test/UnicornHack.DiagnosticClient -- --name <character> [--server <url>] [--insecure] [--log-file <path>] [--verbose] [--action-timeout-ms 10000]

• --name (required): the in-game character name. A new character is auto-created on first connect.
• --server: base URL, default https://localhost:7251. The hub path /gameHub is appended.
• --insecure: trust any TLS cert. Local dev only — never against a remote server.
• --log-file: append diagnostic logs here (stdio is reserved for MCP JSON-RPC; without this flag, logs go to stderr).
• --verbose: enable Debug-level logging.
• --action-timeout-ms: per-action wait for change sets, default 10 000 ms.

The process speaks MCP over stdio. To register it with VS Code (or another MCP client), point that client at the dotnet run invocation above.

Tool Inventory

Read tools (cheap, no server round-trip)

Action tools (each submits to the hub and waits for the post-action change sets)

Each action tool returns a short status string like:

action=MoveOneCell target=0 target2= tick=124 can_act=True hp=18/20 ep=10/10

Dialog / description tools

Recommended Interaction Loop

1. get_status                       # 1 line — knows whether you can act
2. get_map                          # ASCII room
3. get_visible_entities             # who else is here, where, how dangerous
4. <act>: move(direction) | use_ability_slot(slot, ...) | ...
5. tick_before = result.tick from step 1
6. get_log(since_tick=tick_before)  # what happened during your action
7. repeat from 1

Token-Budget Tips

• Prefer get_status + get_map + get_log(since_tick=...) over a full state dump.
• get_log is append-only on the server, so passing a tight since_tick keeps output small.
• Avoid asking for full ability/item dumps every turn unless something changed.

Wire Format Notes

• Movement direction follows UnicornHack.Primitives.Direction: East=0 Northeast=1 North=2 Northwest=3 West=4 Southwest=5 South=6 Southeast=7. Up=8/Down=9 are reported as "unable to move" by the server in MoveOneCell; use travel_to_room or step onto a stairway tile and let the server handle level transitions via change sets.
• move_to packs the cell as (x << 8) | y server-side (Point.ToInt32()); the client tool does this for you.
• The diagnostic client reuses the server's own *Change DTOs (via ProjectReference to UnicornHack.Web) together with the server's MessagePack.Resolvers.GeneratedResolver. The hand-written formatters under src/UnicornHack.Web/Hubs/MessagePack/ only invoke a property setter when its ChangedProperties bit is set on the wire, so the setter side effect that re-sets the same bit is always a no-op. The canonical state instance keeps ChangedProperties = null so writes against it are also no-ops via the ?. guard.

Troubleshooting

• TLS / dev-cert errors: pass --insecure (local only). Alternatively dotnet dev-certs https --trust.
• Hub is not connected / Disconnected: the bootstrap connection failed; check the log file and confirm the server URL/port match the UnicornHack.Web launch profile. After the first failed connect the diagnostic client retries forever in the background — call any action tool again and it will lazily reconnect via EnsureReadyAsync.
• You must install or update .NET to run this application when launching the Web server: the apphost is resolving the runtime from a side-by-side install (e.g. D:\repos\EFCore\.dotnet) whose preview build doesn't satisfy Microsoft.NETCore.App 10.0.0. Set $env:DOTNET_ROOT = 'C:\Program Files\dotnet' in a fresh shell before dotnet run — see Running the Web server.
• get_dialog returns null after show_dialog: server pushes the result asynchronously via ReceiveUIRequest to all clients; poll get_dialog after a short wait.
• Action returns but state looks unchanged: action may have been rejected (e.g. moving into a wall). Check get_log(since_tick=...) for the explanatory entry.
• send_message throws server-side NullReferenceException: expected — the server requires authentication. Tracked as a known limitation.

Adding a New Tool

1. Add a method to one of Tools/ReadTools.cs, Tools/ActionTools.cs, or Tools/DialogTools.cs.
2. Decorate with [McpServerTool, Description("…")].
3. For action tools, route through _conn.PerformActionAsync(...) and _turnTracker.WaitAsync(...) so the response reflects post-turn state.
4. Tools are picked up automatically by WithToolsFromAssembly() in Program.cs.

When the Wire Format Changes

If the server appends a [Key(n)] to a *Change DTO:

1. Add the new key on the server DTO and to its hand-written formatter under src/UnicornHack.Web/Hubs/MessagePack/. The diagnostic client picks up the new field automatically via the ProjectReference.
2. Add a case n: arm to the corresponding MergeX switch in State/StateApplier.cs so the new field is applied onto the canonical state.
3. Expose the new field through the relevant read tool if useful for agents.

Source: AndriySvyryd/UnicornHack — distributed by TomeVault.