| name | diagnostic-client |
| description | Play and inspect UnicornHack from an MCP-driven console client. Use when: you need to drive the running UnicornHack.Web game server programmatically (test a feature end-to-end, reproduce a bug, smoke-test a change, or have an agent play a turn); read live game state without launching the Unity client; submit player actions and observe the resulting change sets; query static descriptions or dialog data. The client is a headless .NET console app in test/UnicornHack.DiagnosticClient that connects to the SignalR GameHub exactly like the Unity client and exposes every hub method plus token-efficient state read tools over an MCP stdio server. |
| argument-hint | Describe the play/inspection task (e.g. "spawn a fresh diag-bot and move east twice", "verify abilities list after equipping a sword"). |
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
- SQL Server LocalDB must be installed and reachable at
(localdb)\mssqllocaldb. The connection string is in src/UnicornHack.Web/appsettings.Development.json.
- 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
- 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.
| Flag | Type | Effect |
|---|
--InitialSeed=<uint> | uint | Pins the random seed for every newly-created character; same seed ⇒ identical map / items / monsters. Omit the flag entirely for a cryptographically-random seed per character (is specify seed 0). |
--RevealLevels=true | bool | Fully reveals every level (only use to pinpoint found issues). |
--RevealRooms=true | bool | Fully reveals each room (only use to pinpoint found issues). |
--ResetDatabase=true | bool | Runs DatabaseCleaner at startup, dropping and recreating the schema. |
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:
- Make sure the
UnicornHack.Web server is running (see Prerequisites).
- Open the Chat panel → tools picker → enable
unicornhack-diagnostic (or MCP: List Servers → Start).
- 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)
| Tool | Returns |
|---|
get_status | One-line summary: name, id, tick, can_act, hp/maxhp, ep/maxep, xp, branch, depth, room size. Call first every interaction. |
get_map(include_legend=false) | ASCII grid of the current room overlaid with player (@), actors (uppercase visible, lowercase remembered), items ($), connections (>/<). |
get_visible_entities(include_remembered=true) | TSV table of actors in the room with hp, heading, next-action tick. |
get_items | TSV table of items in the room. |
get_abilities(only_slotted=false) | TSV table of the player's abilities (id, name, slot, activation, cooldowns, targeting shape:size). |
get_races | Player races/species components. |
get_connections | Stairs/doors in the room. |
get_log(since_tick=-1) | Log entries with Ticks > since_tick. Use since_tick to bound output — pass the tick recorded before your action. |
get_dialog | Last ReceiveUIRequest payload (list-of-objects). null if none. |
get_chat | Recent broadcast messages. |
get_diagnostics | Hub state, last applied tick, collection counts. |
Action tools (each submits to the hub and waits for the post-action change sets)
| Tool | Mapping |
|---|
wait | ActorActionType.Wait |
move(direction) | MoveOneCell. Direction enum: 0=E 1=NE 2=N 3=NW 4=W 5=SW 6=S 7=SE. |
change_heading(direction) | ChangeHeading (turn in place). |
move_to(x, y) | MoveToCell. (x, y) are byte tile coords in the current room; the server pathfinds. |
pickup(item_id) | PickupItem from the current tile. |
drop(item_id) | DropItem. |
equip(item_id, slot) | EquipItem; slot is the EquipmentSlot int. |
unequip(item_id) | UnequipItem. |
set_ability_slot(slot, ability_id) | SetAbilitySlot. Pass ability_id=null to clear. |
use_ability_slot(slot, target_id?, target2?) | UseAbilitySlot. Optional targeting depends on the ability's shape. |
travel_to_room(room_id) | TravelToRoom. |
perform_action(action_type, target?, target2?) | Raw escape hatch for any ActorActionType int. |
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
| Tool | Mapping |
|---|
show_dialog(query_type, arguments=[]) | ShowDialog. Server replies via ReceiveUIRequest; inspect with get_dialog. query_type values: 0=Clear 1=SlottableAbilities 2=PlayerAttributes 3=PlayerInventory 4=PlayerAdaptations 5=PlayerSkills 6=AbilityAttributes 7=ActorAttributes 8=ItemAttributes 9=StaticDescription 10=PostGameStatistics 11=RoomMap. |
describe(topic_id, category) | QueryStaticDescription. category is DescriptionCategory. |
send_message(text) | SendMessage. Currently fails server-side because the server reads Context.User.Identity.Name and authentication is not wired up. |
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
- Add a method to one of
Tools/ReadTools.cs, Tools/ActionTools.cs, or Tools/DialogTools.cs.
- Decorate with
[McpServerTool, Description("…")].
- For action tools, route through
_conn.PerformActionAsync(...) and _turnTracker.WaitAsync(...) so the response reflects post-turn state.
- 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:
- 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.
- Add a
case n: arm to the corresponding MergeX switch in State/StateApplier.cs so the new field is applied onto the canonical state.
- Expose the new field through the relevant read tool if useful for agents.
