Show HN: ArkhamMirror – CIA's Analysis of Competing Hypotheses, Runs in Browser

After adding a fully guided, AI-assisted Analysis of Competing Hypotheses (ACH) feature to ArkhamMirror, my privacy-first open-source Investigative analysis platform, I kept hearing the same request: "I just want to try ACH without setting up Docker and databases."

Message received. I built a standalone version that runs entirely in your browser.

Live tool: https://mantisfury.github.io/ArkhamMirror/ach/ Full ArkhamMirror repo: https://github.com/mantisfury/ArkhamMirror

What it does:

Implements Heuer's 8-step ACH methodology (the CIA technique for avoiding confirmation bias) Guides you through identifying hypotheses, gathering evidence, building the consistency matrix, and running sensitivity analysis Exports to JSON, Markdown, or PDF

Privacy model:

All data stored in browser localStorage Zero network calls after initial page load except to/from your AI provider (if applicable) No backend, no accounts, no telemetry Works offline once loaded Built as part of ArkhamMirror, a 100% local investigative platform I made as a non-coder using AI assistants.

Optional AI assistance:

Connect your own API key (OpenAI, Groq) for AI-powered suggestions Or use local LLMs (Ollama, LM Studio, local Anthropic through proxy) if you run it locally The AI helps suggest hypotheses, evidence items, and ratings – but you make all decisions

Why standalone? The full ArkhamMirror platform is powerful but requires Docker + databases. This gives journalists, analysts and anyone who's curious a zero-friction way to try the ACH methodology immediately.

Analysts have been stuck with crappy spreadsheets for a long time. Now they (and you) have a free upgrade. Source: https://github.com/mantisfury/ArkhamMirror/tree/main/ach-sta...

If you try it out, please let me know what you think.