ArkhamMirror: Airgapped investigation platform with CIA-style hypothesis testing
13 comments
·December 16, 2025ArkhamMirror
I got tired of expensive SaaS tools that want my sensitive documents in their cloud. I built ArkhamMirror to do forensic document analysis 100% locally, free and open source.
What makes this different:
Air-gapped: Zero cloud dependencies. Uses local LLMs via LM Studio (Qwen, etc.)
ACH Methodology: Implements the CIA's "Analysis of Competing Hypotheses" technique which forces you to look for evidence that disproves your theories instead of confirming them
Corpus Integration: Import evidence directly from your documents with source links
Sensitivity Analysis: Shows which evidence is critical, so if it's wrong, would your conclusion change?
The ACH feature just dropped with an 8-step guided workflow, AI assistance at every stage, and PDF/Markdown/JSON export with AI disclosure flags. It's better than what any given 3-lettered agency uses.
Tech stack: Python/Reflex (React frontend), PostgreSQL, Qdrant (vectors), Redis (job queue), PaddleOCR, Spacy NER, BGE-M3 embeddings.
All MIT licensed. Happy to answer questions about the methodology or implementation! Intelligence for anyone.
Links: Repo https://github.com/mantisfury/ArkhamMirror
ACH guide with screenshots at https://github.com/mantisfury/ArkhamMirror/blob/reflex-dev/d...
V__
What field are you in, sounds interesting that one would need such a tool?
ArkhamMirror
It's not just for people doing interesting things. It just helps people answer questions about stuff. The stuff can be interesting or boring or dangerous or silly. The last question I tested the ACH tool on was "Did William Shakespeare really author all of the works he was credited for?" - You can use this stuff to research whatever you want. That's the point of it - it's no one's business what you are interested in getting to the bottom of.
cess11
Description on the repo says it's for journalism, but I build similar rigs that I use for research in companies that have entered bankruptcy proceedings.
Commonly there is a lot of information and it might as well be unstructured, and then I need to get answers quickly because my clients aren't going to pay me for going about it slowly.
ArkhamMirror
It's mainly useful for journalism purposes, yes. Audit and compliance uses were also a consideration. It's a unified tool for right now, but I'm working on turning the base of it into the frame and adding individual shards for specialized applications.
ArkhamMirror
In case it wasn't clear, the ACH update is on the reflex-dev branch -
Theofrastus
It's always interesting to stumble upon a bubble you never heard of.
This is super interesting. I will probably (hopefully?) never need to use it, but interesting nonetheless. It also makes sense to have this type of application airgapped. Journalists need to have near-perfect OPSEC depending on what they are working on.
ArkhamMirror
Thanks for the interest! I agree, the less people that need it the better, but I want it to exist just in case.
ckbkr10
The idea is good. I do think that is going to be the future for high volume data leaks like the Snowden or Epstein files.
I do think though that this approach will become annoying quick:
https://github.com/mantisfury/ArkhamMirror/blob/main/scripts...
ArkhamMirror
The cheesy noir persona is for the AI assisted install and that's it. Inside the app, the prompts are strictly business. (They still have roles, but not "characters" or "personas").
jrflowers
Unrelated to this post but it is a fascinating thought that at some point in your life, before you die, you will see the stupidest thing that you have ever seen in your entire life, and then you either die immediately or only see less stupid things for an unknown period of time before you die, and none of us can ever know where we are in that continuum.
chamomeal
Huh that uh. That is something to think about
I'm wondering if the ACH Methodology could be used as a general purpose Chain-of-Thought variant.