ModWrench

ModWrench™

An MCP server that connects your AI assistant to mod platforms and to your own modding setup, so you can ask questions in your AI client instead of clicking through web UIs.

It runs on your machine. No account, no service, no server anyone operates.

The website, modwrench.171county.workers.dev, is a static page. Its Try section reads a crash log or compares crew lists in your browser, with ModWrench's own code, and sends nothing (how).

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Paste a crash log. Get the mod that caused it.

SomeArmorMod.esp is named as a suspect, and SomeArmorMod.dll is sitting at frame 2 of the call stack. ModWrench parsed the log and laid out what is in it. It did not decide the cause — that is the model's job, and the page says so.

Search every platform you have connected, with the author on every row.

These are not screenshots of a website. Each is an MCP Apps page: one self-contained HTML document with no external scripts, no stylesheets, no fetches and no images. Every tool answers in text that any client can show and a model can read. Crash logs, mod lists, dependencies and load orders, known conflicts, the deck, Patch Day, Crash Whisperer and the Doctors also have a page, drawn only in a client that supports MCP Apps: the tool points at its page, the client fetches it and draws it, and the data the page draws comes with the answer as structured data. A client that can't draw pages never fetches one and is never sent that data, so it gets the text answer and no HTML at all. The pictures above were drawn in a stand-in for an MCP Apps host. Since then, on Windows 11, the Crash Whisperer page has run in Claude Desktop (called by Claude itself) and in MCP Inspector, and the deck in MCP Inspector and VS Code's Copilot Chat. The Patch Day page has shown a check that couldn't run in VS Code, but not a full report; the other pages haven't been tried in a real client yet.

Patch Day, Crash Whisperer and the Doctors (mw_patch_day, mw_crash_whisperer, mw_doctor) keep their text to a few lines, and the full report goes to their page. The structured data goes only to clients that say they can draw pages, because some clients hand the model the structured data *instead of* the text, which would turn a ten-line answer into a long one. If you want it anyway, for a script or an agent that reads it, set MODWRENCH_STRUCTURED=always; MODWRENCH_STRUCTURED=never sends it to nobody, and then no tool points at a page, since without its data a page could only repeat the text answer. MODWRENCH_UI=off switches every page off, and with them the structured data, unless MODWRENCH_STRUCTURED=always asks for it. The pages make no network requests and keep nothing; TRUST.md and the other pages say what they can and can't do.

The optional HTTP server, @modwrench/remote, decides the same way. It keeps a session for each client (in memory only; nothing is written, and a session left unused for 24 hours is closed), so the server answering a tool call is the one that saw whether the client draws pages, and its Thunderstore mod lists and dependency tools send a page's data only to clients that do. A client whose session was closed gets "Session not found" until it reconnects.

The Doctors (mw_doctor, or /mw-doctor) answer "is my setup ready?", and they are the boring half of modding support: a lot of "my mods keep breaking" threads end with a cause that isn't a mod. The Setup Doctor looks at where the game, Mod Organizer 2 and Vortex's staging folder live (Program Files, OneDrive and the other folders Windows protects or syncs), whether Vortex's staging folder is on the game's drive as its hard links need, how much room is left on the drive, and, for Skyrim Special Edition and Fallout 4, the plugin list: plugins whose master is missing, switched off or loaded too late, the limit of 254 full and 4,096 light plugins (255 full in a Fallout 4 list with no light plugin on), entries for plugins that are gone, Mod Organizer 2 and the game's own list disagreeing, clutter in MO2's Overwrite folder, and crash loggers (none, or two that fight). The Deck Doctor, on Linux and the Steam Deck, looks at which Steam holds the game (regular or Flatpak), whether Proton has made the game's prefix, BepInEx's winhttp launch override, which app opens nxm:// links, whether a library sits on an NTFS, FAT32 or exFAT drive, and folder names that differ only by capital letters. Every finding says what it rests on (your files, a documented rule with its source named, or ModWrench's own guess), and the report lists what it can't see: antivirus, the pagefile, what MO2's virtual file system shows the game while it runs. Why a game crashed is Crash Whisperer's question, and the report says so. It is read-only and local: no network, no program started, nothing written, no folder path in the answer. A clear report means the checks that can run from files passed. It does not mean the game starts, and it says so. It was built from the tools' own documentation and tested on constructed installs; it has not been run against a real one. TRUST.md lists what it opens and where it is unsure.

Crash Whisperer (mw_crash_whisperer, or /mw-crash) answers "why did my game crash?". Ask with nothing else and it reads the newest crash log your logger wrote (or the one you point at or paste), says in plain words what happened, and ranks the names the log points at, each with its reasons and a label for what the reason rests on: the log, your files, a published rule, or ModWrench's own guess. It checks your setup for the usual causes, compares your other recent Crash Logger SSE and Buffout 4 crash logs to see whether the same name keeps coming up, and writes the post you'd put on a forum, GitHub or Discord, or send to the mod's author, with the personal details it recognises (your name, computer name, folders, addresses, keys) taken out. That is pattern matching, so it can miss something: read a post before you send it. Besides the call stack, a post carries what the log names: the objects the logger lists and the plugins that changed them, the game files, Papyrus functions and object types named in the registers and stack, a NetScriptFramework log's DLL list, and BepInEx's, Unity's and each plugin's version. When the log has no plugin list, or the logger couldn't write one, the post says so, and where the logger couldn't write it the post leaves a blank for your load order. A ranking is a lead, never a verdict, and it never calls anything safe. It says what the log shows the game was working with (the objects it lists, game files, the kinds of object in the registers, Papyrus functions), and when the game stopped inside a library other mods need, such as RaceMenu or JContainers, it says not to remove it and points at the mod that may have called it, when the log shows one. When no name stands out, it suggests the Doctors, which check the setup problems a crash log may not name. It reads Crash Logger SSE, Buffout 4, NetScriptFramework and BepInEx logs; the setup check covers Skyrim Special Edition for now. Reading the log from your disk is the private way to use it: what it recognises comes out before anything reaches your AI. A log you paste into the chat, or a path you type, has already reached it as you typed it, and the log file itself is never cleaned, so share a help post and not the file. TRUST.md has the rest, including a plain list of what it does not catch.

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What it does

Four attachments. Install one, some, or all — @modwrench/cli composes whichever you've configured into a single MCP entry.

Nexus Mods — search mods, read changelogs and file lists, check versions, browse trending and recently updated, preview what's inside an archive before downloading, reverse-lookup a file by MD5, and endorse a mod when you ask it to. *(15 tools)*

mod.io — search and browse mods across the games mod.io hosts; pull mod details, files, tags, stats, dependencies and comments. *(17 tools)*

Thunderstore — browse communities, search mods, read full version history, and resolve dependency trees. No credential needed; the read API is public. *(9 tools)*

Workbench — local, on your machine. Find your installed games, mod managers and loaders; read your load order out of MO2, r2modman or Vortex; parse a crash log from Crash Logger SSE, Buffout 4, NetScriptFramework or BepInEx, or have it explained: what happened, which names the log points at and how sure that is, and a help post ready to copy; look a mod up across platforms; check known conflicts; check, before or after a game patch, whether your script extender plugins will survive it (SKSE for Skyrim Special Edition and Anniversary Edition, F4SE for Fallout 4); and run the Doctors, a read-only health check of the setup behind the crash (plugin masters and limits, where things live, MO2's Overwrite folder, and on Linux and the Steam Deck the Steam, Proton and nxm:// side); check what LOOT's masterlist says your active plugins need, for Skyrim Special Edition and Fallout 4, which looks only for whether those files are there; and run Pulse, which checks the Thunderstore mods in an r2modman profile for updates, deprecated mods and mods Thunderstore no longer has, after telling you exactly how many requests it would send and waiting for your yes; and run Crew Check, which makes a short list of your Thunderstore mods and versions to share with your co-op crew and compares the lists they paste back, with no network at all; and draw a Trust Card for one mod: who made and uploaded it, where it lives, its dates and the platform's own numbers, each from the platform's record and with no score of ModWrench's own; and read the News: a game's latest official announcements and patch notes on Steam and its modding tools' latest releases on GitHub, again after telling you what it would send and waiting for your yes. *(14 tools)*

The conflict check reads two sources: LOOT's masterlist, fetched live for Bethesda games, and a small conflict list bundled inside the package for games LOOT does not cover. That bundled list ships empty — all three files contain [] — so today it asserts nothing. It is named here because it is a channel that could carry claims about someone's mod in a future release, and npx pulls the latest version automatically unless you pin.

Plus three meta tools: one activates a platform mid-session, one opens the deck, which shows which platforms are connected (a page in clients that support MCP Apps, the connector list as text everywhere else), and one drafts feedback for ModWrench's maintainers as a GitHub issue that you read and post yourself (it sends nothing).

58 tools. 57 of them read. One writes — see The one thing it writes.

It also registers eight slash commands your MCP client will offer you: /modwrench opens the deck, /mw-find searches every connected platform at once, /mw-crash asks why your game crashed