ExileAPI Plugin Dev MCP

An MCP server that gives coding agents a bounded development workflow for ExileAPI plugins. The repository also contains a disabled-by-default ExileAPI companion plugin reserved for a future read-only telemetry bridge.

Scope

• Detect local ExileAPI compiler references.

• Create an independent Git repository under ~/ExileApiPlugins/<PluginName> and link it into Plugins/Source/<PluginName>.

• Prepare the linked source tree for ExileAPI's in-game Build/Reload action.

• Read the resulting bounded Errors.txt output.

It deliberately does not expose DevTree's dynamic C# evaluator, read or write process memory, or send game input. The current companion plugin has no IPC surface; a future runtime bridge must be separately reviewed and read-only.

Related MCP server: mcdev-mcp

Local development

python3 -m venv .venv
.venv/bin/pip install -e .
.venv/bin/exileapi-plugin-dev

Controller-side verification

The collection-index path resolver is covered by a game-independent .NET test project:

"${DOTNET_ROOT:-$HOME/.dotnet}/dotnet" test \
  tests/ExileApiPluginDevBridge.Core.Tests/ExileApiPluginDevBridge.Core.Tests.csproj

A full bridge build additionally needs the matching ExileCore.dll and GameOffsets.dll directory:

"${DOTNET_ROOT:-$HOME/.dotnet}/dotnet" build ExileApiPluginDevBridge.csproj \
  -p:EnableWindowsTargeting=true \
  -p:exapiPackage=/path/to/pinned/exileapi-runtime

The main bridge project explicitly excludes tests/**/*.cs so ExileAPI's source compiler does not compile xUnit sources or nested test build artifacts.

The repository is linked into ExileAPI source plugins at:

~/ExileApi-Compiled/Plugins/Source/ExileApiPluginDev -> ~/ExileApiPlugins/ExileApiPluginDev

ExileAPI owns compilation and reload. Use its in-game Build/Reload button after source changes; no Linux build worker is required. Errors.txt may be retained after a successful build, so the MCP also reports its modification time.

The enabled bridge writes a small read-only runtime-status.json after successful initialisation and area changes. Its default path matches the existing Z: mount used by ExileAPI on this machine; it can be changed in the plugin settings.

For larger diagnostics, use Capture snapshot in the bridge's ExileAPI menu. It writes game-snapshot.json only when pressed. Defaults are: depth 6, 500 total nodes, 100 collection entries per node, 512 characters per string, and no memory addresses. read_game_snapshot reads the frozen result through MCP.

ExileAPI core snapshots

list_core_snapshots, inspect_core_snapshot, find_core_snapshot_paths, and read_core_snapshot_member work with ExileAPI's snapshots/*.exapisnap files. The indexer reads 512-byte TAR headers and seeks over member bodies; it never extracts or feeds a multi-gigabyte snapshot to the model. find_core_snapshot_paths supports required and excluded path terms; read a member only after narrowing it through the indexed path list.