Runtime Engines Die, Specs Survive: Why Declarative Wins

A Brief History of AI Persona Projects The idea of giving AI agents distinct personalities isn’t new. Several projects have tried. Most are dead. OpenSouls (⭐294) — Dead OpenSouls called themselves “NextJS + Vercel for the minds of digital beings.” They built an impressive TypeScript runtime: WorkingMemory: Immutable collections of agent memories cognitiveSteps: Functions that transform memory state MentalProcesses: State machines for behavior (happy → frustrated → curious) Today: website down, docs gone, repos deleted, npm silent for over a year. ...

February 18, 2026 · 3 min · Tom Lee

What Happened to OpenSouls? Lessons from a Dead AI Persona Engine

The Rise OpenSouls (⭐294 on GitHub) positioned themselves as “NextJS + Vercel for the minds of digital beings.” They built an impressive runtime engine: WorkingMemory: Immutable memory collections cognitiveSteps: Functions that transform memory and return typed responses MentalProcesses: State machines for behavioral modes (introduction → guessing → frustrated) They drew inspiration from neuroscience and psychology. Their @opensouls/soul npm package reached 76 versions. The Fall Today: 🔴 Website (opensouls.com) — down 🔴 Documentation (docs.opensouls.com) — down 🔴 Most GitHub repos — deleted or private 🔴 Last npm publish — over a year ago No shutdown announcement. Just silence. ...

February 17, 2026 · 2 min · Tom Lee

Soul Spec Architecture: Why We Split Personality Into Files

The Problem With One Big Prompt Most AI agents today get their personality from a single system prompt. It works — until it doesn’t. Here’s what a typical “personality prompt” looks like in practice: You are Alex, a friendly coding assistant. You speak casually and use emoji. You remember the user prefers Python. When asked about databases, recommend PostgreSQL. Don't discuss politics. Your tools include: file reader, web search, terminal... Personality, memory, behavioral rules, and tool configuration — all in one string. This is the equivalent of writing your entire application in a single file. ...

February 17, 2026 · 4 min · Tom Lee