#Fathom (for JetBrains Rider)

1 messages · Page 1 of 1 (latest)

cobalt parrot
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Fathom is a free && open-source Rider plugin that helps AI coding assistants better understand your Unreal Engine 5 C++ projects. Whether you use Claude, Gemini, Codex, OpenCode or any other LLM agent, Fathom gives them missing tools to help reduce hallucinations and increase your productivity.

*Why Fathom? *Because your UE5 projects are more than just C++ code!
They include various binary files that are linked to the C++ code. Without understanding what's happening "in engine", LLMs working on UE5 C++ projects frequently hallucinate class names, miss Blueprint relationships, and produce code that doesn't match your project's actual structure. They can only see the files you feed them, and they have no way to query your project as a whole.

Fathom solves this by exposing your project's full picture through MCP tools that any compatible AI assistant can call on demand.

https://github.com/Tideshift-Labs/Fathom

GitHub
GitHub - Tideshift-Labs/Fathom: A Rider Plugin for improving UE5 C+...

A Rider Plugin for improving UE5 C++ development for your LLM agent of choice - GitHub - Tideshift-Labs/Fathom: A Rider Plugin for improving UE5 C++ development for your LLM agent of choice

ripe creek
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This is pretty interesting

cobalt parrot
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Thanks @ripe creek I've been using it myself but haven't really put it out there yet. A couple people in discord have been finding it pretty valuable in their Rider + C++ w/ LLM workflow

ripe creek
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That's the workflow I use as well

cobalt parrot
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Give it a go. Give me a shout if you have any issues so I can improve it.

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It's on the jetbrains marketplace (required recent version of Rider)

ripe creek
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Been using it for like an hour to do just to review things and its doing well with tool calling

cobalt parrot
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Nice!

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If you're like me and leave Live Coding on (I restart UE Editor when appropriate right after), then it gets instant feedback through that as well

ripe creek
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Oh beautiful 😍

cobalt parrot
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(meaning Fathom has a live code tool call as well)

ripe creek
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Its working well. What does your road map look like?

cobalt parrot
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Eventually add Unity support (maybe)

ripe creek
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I wrote an editor plug-in as well for our dev team. Im not sure if I want to release to public or not though.. its a pretty fleshed out DAM plug-in with a Golang backend that sits on a NAS.

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Ah okay

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You could see what pythons api in UE has to offer too and see if it can add additional benefits

cobalt parrot
cobalt parrot
ripe creek
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We needed a way to share assets on our Fab accounts with the team so we could see what could be useful in our various projects.

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The plug-in just interfaces with the backend, and you can add multiple servers in the plug-in. Like if other users had assets or plug-ins to contribute from their own storage solutions. Currently its just on my NAS though where I've been building a bit of a library of my own stuff of some things that can be used in our projects.

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I initially made it though because we have a couple guys on the team that work remote, and one of which has a large catalog of props and such that could be useful in different scenarios

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Backend is just ran through docker and exposes an api to the plug-in. Supports downloading and chunked uploads.. and other stuff. Its pretty nice lol

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RBAC support too of course on the backend

ripe creek
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Here it is. I haven't tried it yet though.

https://www.vibeue.com/

VibeUE - AI-Powered Unreal Engine Development | Python API & MCP Tools

VibeUE brings AI directly into Unreal Engine with In-Editor Chat and Python API access. 9 MCP tools plus 24 Python services with 798 methods for Blueprints, Animation, Animation Montages, Skeletons, Enums/Structs, Materials, Widgets, Niagara, Input, Level Actors, Data Assets, Runtime Virtual Textures, StateTree Behavior, Project/Engine Settings,...

cobalt parrot
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Looks neat! Different philosophy I think... In-Editor AI chat imho is no bueno for C++ dev. And this one is about helping you build out BPs and other uassets whereas Fathom is targetted at people like me who want MOST of their game logic in C++ (barely any BP logic if any) and also want to control what they do in the editor themselves (creating DAs, DTs, etc)

ripe creek
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Ah yes more of a data driven architecture

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Ive been diving into UE C++ development for like 2-ish weeks so far so im still learning what you can do in code vs what's required to be in BP.

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I could just have it backwards though. 😆

cobalt parrot
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exactly. I'm fairly new to it too, but I prefer the data driven arch

ripe creek
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Same here. Slap in some core logic, and make it modular with data driven assets (DA/DT etc) and call it a day lol

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Modularity 🧡