cities2-mcp 0.1.9

Local MCP server for Cities: Skylines II game knowledge and modding workflows.

Cities2-MCP

Cities2-MCP — a local MCP server for Cities: Skylines II game knowledge and modding tools.

It gives AI assistants access to a local, searchable version of the Cities: Skylines II Wiki, plus tools for creating, inspecting, building, and packaging CS2 mod projects.

What It Can Do

Search Game And Modding Information

The server includes a prepared text corpus from the Cities: Skylines II Wiki. An AI assistant can:

• search the wiki
• fetch full pages by page id
• retrieve reference-style snippets for game systems and modding topics
• answer questions during your agent session

This is useful for questions about game mechanics, modding APIs, toolchain setup, project structure, localization, UI mods, and related CS2 development topics.

Search The Local Game Encyclopedia

When Cities: Skylines II is installed locally, Cities2-MCP also tries to read the in-game Encyclopedia from the user's own game files. This source is enabled by default when the server can find Cities2_Data/Content/Game/Locale.cok, especially for standard Steam installs.

The extracted Encyclopedia index is cached locally on the user's machine and rebuilt only when the source game file, detected Steam build id, locale, or extractor version changes. Extracted game text is not committed to this repository, shipped in releases, or part of the redistributed wiki corpus.

If the game install is not found automatically, set CITIES2_GAME_DIR to the Cities: Skylines II install directory or CITIES2_LOCALE_COK to the full Locale.cok path.

Help With Mod Project Workflows

The server also includes local workflow tools for CS2 mod projects. An AI assistant can:

• scaffold C# code, UI, or hybrid mod project templates
• write files inside configured workspaces
• list project trees
• run project builds and analyzers
• package project output
• dry-run launching Cities: Skylines II with selected flags

These tools are meant for local development workflows. They can write files and run commands, so configure workspaces deliberately.

Use Agent Skills

Cities2-MCP ships two agent skills that teach compatible agents how to query and interpret the MCP sources effectively:

• cities2-knowledge answers gameplay, city-system, and player-facing patch/update questions from both the bundled wiki corpus and the local game Encyclopedia.
• cities2-modding answers modding questions and guides local mod project workflows.

These skills are stored in skills/. Install or copy them into your agent's skill directory if your client supports Agent Skills. They are the recommended way to get natural answers to questions like "how do I grow office demand?" or "what changed in the latest patch?" because they tell the agent to use keyword queries, fetch full pages or entries, compare source authority, synthesize an answer, and include compact source notes naming the Game Encyclopedia entries and linked wiki pages used.

Licensing

The MCP server code is licensed under the MIT License. The included cities2_mcp/data corpus is licensed under Creative Commons Attribution-ShareAlike 3.0; source attribution and transformation notes are in cities2_mcp/data/ATTRIBUTION.md.

Privacy

Cities2-MCP runs locally and does not collect telemetry. See PRIVACY.md for details.

Quick Install

Claude:

/plugin marketplace add mayor-modder/Cities2-MCP
/plugin install cities2-mcp@cities2-mcp

Codex:

codex plugin marketplace add mayor-modder/Cities2-MCP

Then install Cities2-MCP from the marketplace in the app. See INSTALL.md for Claude Desktop, Codex Desktop, direct MCP config, workspace setup, build prerequisites, and troubleshooting.

Included Wiki Corpus

The packaged server reads the prepared corpus from cities2_mcp/data by default. The corpus contains page metadata and JSONL indexes used by the MCP retrieval tools.

Corpus layout:

• cities2_mcp/data/LICENSE
• cities2_mcp/data/ATTRIBUTION.md
• cities2_mcp/data/manifest.json
• cities2_mcp/data/index/pages.jsonl
• cities2_mcp/data/index/chunks.jsonl

MCP Tools

Game and modding knowledge:

• search(query, limit=5)
• get_page(page_id)
• query_reference(query, limit=5)
• get_snippets(query, limit=3)
• search_encyclopedia(query, limit=5)
• get_encyclopedia_entry(entry_id)
• source_status()

Mod project workflow:

• scaffold_project(name, template, target_dir?, metadata?, options?)
• write_project_file(project_dir, relative_path, content, mode=create|replace|upsert)
• list_project_tree(project_dir, glob="**/*", include_hidden=false, max_files=2000)
• build_project(project_dir, profile=debug|release, steps?, clean=false, package=false, timeout_sec=300)
• analyze_project(project_dir, profile=auto|cities2-csharp|cities2-ui|cities2-hybrid, strict=true)
• package_project(project_dir, output_dir?, package_name?, exclude_globs?)
• launch_cities2(executable?, flags?, platform=auto|mac|windows|linux, dry_run=true)

Agent Skills

Skills live under skills/:

• skills/cities2-knowledge/SKILL.md
• skills/cities2-modding/SKILL.md

The marketplace install includes these skills. In Codex, run /skills or type $ to mention $cities2-mcp:cities2-knowledge or $cities2-mcp:cities2-modding; Claude exposes them as /cities2-knowledge and /cities2-modding. Gameplay and update answers should include compact source notes that mention the local Game Encyclopedia entries and link to the relevant CS2 Wiki pages when available.

Project templates are stored at:

• cities2_mcp/templates/cities2-csharp
• cities2_mcp/templates/cities2-ui
• cities2_mcp/templates/cities2-hybrid