RenForge

RenForge is an MCP (Model Context Protocol) server, CLI, and web dashboard for working with Ren'Py visual-novel projects.

It lets an AI agent — or a human via the dashboard — inspect a project, launch and drive a running game, read/write game state, capture screenshots, generate translations, find orphaned assets, run builds, and search Ren'Py's docs.

Status: alpha, actively developed. The core surfaces (MCP tools, in-game bridge, CLI, dashboard) are functional; APIs may still change.

What it does

• Project inspection — summarize structure, scan scripts/labels/assets, parse lint output.

• Live game control — launch a project with an injected in-game bridge, then advance dialogue, list/select choices, evaluate expressions, get/set store variables, send focused text/key/scroll input, poll pushed events, and capture frames the model can literally see.

• Autopilot — auto-play the game across branches and report label coverage and crashes.

• Assets & translations — find orphaned/missing image+audio assets, list languages, compute translation stats, generate/update game/tl/<lang>/ files, export dialogue as text.

• Builds — package desktop distributions and web builds.

• Docs — search and read Ren'Py's offline documentation.

• Web dashboard — Starlette + WebSocket UI with a live story map, activity log, autopilot coverage, lint view, and game-state controls.

Related MCP server: OpenWebGAL Assistant

Quick start

Requires Python 3.11+. With uv installed, no setup is needed:

# Start the web dashboard
uvx --from "renforge[ui]" renforge ui

Then choose your game in the dashboard's project picker — no path to type. (Or skip the picker with --project /path/to/your/game.)

Prefer a persistent install? pipx puts renforge on your PATH in an isolated environment:

pipx install "renforge[ui]"
renforge ui

On managed systems (Debian/Ubuntu), plain pip install is blocked by PEP 668 — use uvx or pipx instead.

Use with your AI agent

The complete operational reference is available in docs/MCP.md. This README keeps the installation examples below; the guide documents the full tool catalogue, safety guards, visual interaction, and troubleshooting.

The MCP server command is the same everywhere:

uvx renforge@latest serve

The @latest suffix makes uvx fetch the newest published RenForge on each start instead of silently reusing a cached older build — so new tools land without a manual uv cache clean. Drop it (uvx renforge serve) if you prefer to pin whatever is already cached.

Every RenForge tool takes a project_path argument, so the agent passes your game's path on each call — no path substitution in the configs below. Copy them as-is. The optional --project flag on renforge serve still sets a default project for activity logging.

Claude Code

claude mcp add renforge -- uvx renforge@latest serve

Claude Desktop, Cursor, Windsurf, Cline, Gemini CLI

These clients share the same mcpServers JSON shape — add this to the config file listed in the table above:

{
  "mcpServers": {
    "renforge": {
      "command": "uvx",
      "args": ["renforge@latest", "serve"]
    }
  }
}

VS Code (GitHub Copilot)

.vscode/mcp.json in your workspace:

{
  "servers": {
    "renforge": {
      "command": "uvx",
      "args": ["renforge@latest", "serve"]
    }
  }
}

Zed

In settings.json:

{
  "context_servers": {
    "renforge": {
      "source": "custom",
      "command": "uvx",
      "args": ["renforge@latest", "serve"]
    }
  }
}

Codex CLI

codex mcp add renforge -- uvx renforge@latest serve

Or edit ~/.codex/config.toml (on Windows: %USERPROFILE%\.codex\config.toml):

[mcp_servers.renforge]
command = "uvx"
args = ["renforge@latest", "serve"]

Verify it works

After configuring your client, ask the agent:

Inspect my Ren'Py project at /path/to/game

The agent should call renforge_inspect_project with that path and return a JSON summary of the project (labels, scripts, assets, and related metadata).

Windows / GUI clients: Desktop apps (Claude Desktop, Cursor, etc.) may not inherit your shell PATH. If uvx is not found, set command to the absolute path of uvx (for example C:\Users\you\.local\bin\uvx.exe).

Don't have uv? Run pipx install renforge, then replace uvx renforge@latest with renforge in your config (and pipx upgrade renforge to update).

Install (dev)

python -m venv .venv
source .venv/bin/activate
pip install -e .             # MCP runtime (includes fastmcp)
pip install -e ".[fastmcp]"  # alias for the base install
pip install -e ".[ui]"       # dashboard (starlette, uvicorn, watchfiles)
pip install -e ".[test]"     # pytest

The server falls back to a compatibility mode with a clear message if fastmcp is not installed (for example after a minimal manual install).

Usage

CLI

renforge --version
renforge inspect <project>      # lightweight project summary (JSON)
renforge serve [--project .]    # start the MCP server (stdio transport)
renforge ui [--project <project>] [--port 8765]  # start the web dashboard

MCP server

renforge serve exposes the tools below to any MCP client. A subset:

• renforge_inspect_project, renforge_scan_project, renforge_parse_lint

• renforge_info, renforge_context (discover the project selected in the dashboard)

• renforge_find_references, renforge_inspect_image

• renforge_launch, renforge_jump, renforge_new_game, renforge_stop

• renforge_game_state, renforge_game_state_compact, renforge_inspect_screen, renforge_advance, renforge_control, renforge_send_input, renforge_saves, renforge_list_choices, renforge_select_choice, renforge_eval, renforge_get_var, renforge_set_var, renforge_poll_events, renforge_get_errors, renforge_wait_until, renforge_screenshot

• renforge_list_ui_elements, renforge_click_element, renforge_click_at, renforge_find_image_on_screen

• renforge_get_displayable_bounds, renforge_position_element, renforge_diff_screenshots

• renforge_autopilot

• renforge_assets, renforge_languages, renforge_translation_stats, renforge_generate_translations, renforge_export_dialogue

• renforge_web_build, renforge_distribute

• renforge_search_docs, renforge_get_doc, renforge_list_docs

Large-project calls are bounded at the tool boundary: renforge_scan_project accepts sections, file_glob, symbol, offset, and limit, while renforge_game_state_compact omits the full variable store unless variable_names or variable_prefix is requested. The original renforge_game_state remains backward compatible. renforge_screenshot and renforge_inspect_image accept crop coordinates plus scale for close visual inspection without a separate image-processing script. For visual interaction, call renforge_list_ui_elements first: it returns visible controls, bounds, semantic text, and a frame_id. Pass that id to renforge_click_element or renforge_click_at so a stale screenshot cannot silently produce a wrong click. renforge_find_image_on_screen locates a local PNG/template in the current frame and returns bounds, center, and confidence; its result also includes a frame_id suitable for the guarded click call. Template bounds are in coordinate_space: "screenshot"; pass that value to renforge_click_at so Ren'Py's logical coordinates are derived correctly even when WSLg scales the captured image.

renforge_game_state keeps its default response unchanged. Pass include=["metrics", "audio"] to opt into compact render/cache/window metrics and registered-channel audio state; only those two include values are accepted.

Live control

renforge_launch injects a bridge into <project>/game/ (removed on teardown) and starts the game. If the matching dashboard is running, MCP delegates launch to that process so it inherits the dashboard's display environment; otherwise it launches directly. Fully headless CI should wrap direct launches with xvfb-run.

The dashboard publishes its selected project in a per-user local runtime registry. Agents can call renforge_info or renforge_context first instead of guessing the game path. renforge_jump resolves a label to file:line and restarts through Ren'Py's supported warp path; renforge_new_game starts a fresh process at the project's start label through that same path.

GOD-mode edit and branch check

Use real labels and visible choice text from your project in this compact launch-to-diagnostics loop:

project = "/path/to/game"
renforge_launch(project_path=project)
edit game/script.rpy
renforge_control(project_path=project, action="reload_script")
renforge_wait_until(project_path=project, label="edited_label", timeout=30.0)
renforge_screenshot(project_path=project)
renforge_saves(
    project_path=project,
    action="save",
    slot="branch-a",
    extra_info="after hot reload",
)
renforge_list_choices(project_path=project)
renforge_select_choice(project_path=project, text="Branch B")
renforge_wait_until(project_path=project, label="branch_b", timeout=30.0)
renforge_get_errors(project_path=project)

renforge_screenshot returns the current frame as an image. The save call creates a named checkpoint before selecting Branch B; use renforge_saves(project_path=project, action="load", slot="branch-a") to return to it. renforge_wait_until accepts exactly one of label, screen, or expr, and timeout is capped at 120 seconds.

Web dashboard

renforge ui serves a dashboard (default 127.0.0.1:8765) with a story map, activity log, autopilot coverage, lint view, and live game controls over WebSocket. Pick a project from the in-app project picker, or pass --project <project> to open one directly.

Examples

A small sample project lives in examples/demo_game/.

Architecture

src/renforge/
  cli.py            # argparse entrypoint (inspect / serve / ui)
  server.py         # MCP app bootstrap + fallback + tool registration
  bridge/           # in-game .rpy bridge, launcher, and client
  tools/
    live.py         # running-game control (launch, eval, screenshot, ...)
    project_ops.py  # assets, translations, builds, docs
    static.py       # inspect / scan / parse-lint
  ui/               # Starlette dashboard (server, ws, graph, activity, poller)
  dashboard_client.py # private display-bound delegation to the dashboard
  image_ops.py       # local/live image crop and zoom primitives
  navigation.py      # shared label and file:line warp resolution
  session_registry.py # dashboard-to-MCP active-project discovery
  symbols.py         # Ren'Py-aware token/reference lookup
  util/             # filesystem + subprocess helpers
  sdk.py            # Ren'Py SDK download/cache
  scanner.py        # script/label/asset scanning
  lint.py           # lint runner + parsing
  autopilot.py      # branch auto-play + coverage
  translation.py    # translation generation/stats

Packaging uses hatchling; the console script is renforge = renforge.cli:main.

License

MIT