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What is OSTwin?

OSTwin is an operating system for AI agents. It takes a markdown plan, decomposes it into a dependency graph of epics, spins up isolated war-rooms, and orchestrates role-based agents to execute each epic — all without writing a single line of agent code.

The Problem

Building with AI agents today means fighting three unsolved problems:

ProblemWhat happensOSTwin’s answer
Agent sprawlEvery task gets a new bespoke agent. Config drifts. Nothing is reusable.Roles + Skills compose agents from portable building blocks
Context explosionAgents share one massive context. Prompt pollution kills quality.War-rooms isolate each epic’s context, memory, and tools
No isolationOne agent’s bad tool call corrupts another’s state. No blast radius control.MCP servers are scoped per war-room. Filesystem boundaries enforced

Most multi-agent systems treat agents as long-running processes with hardcoded capabilities. OSTwin inverts this: agents are ephemeral sessions assembled on demand from composable building blocks. The building blocks are portable, the sessions are disposable, and the coordination is filesystem-native.

Three Axes of Agent Identity

OSTwin defines every agent through three orthogonal axes. This is the core abstraction that makes the system composable:

Identity (WHO)
│ role.json + ROLE.md
│ personality, constraints, style
├──────────── Expertise (WHAT)
│ │
│ │ SKILL.md files
│ │ domain knowledge, workflows
│ │ loaded on demand
└──────────── Execution (HOW)
│ MCP servers
│ scoped tool access
│ isolated per war-room

Identity is stable — an architect role always reasons like an architect. Expertise is swappable — the same architect can load Unity skills or web skills. Execution is isolated — each war-room gets its own tool sandbox.

Core Flow

Every OSTwin run follows the same pipeline:

PLAN.md → Parse → DAG → Schedule Waves → Spawn War-Rooms → Execute → Report
│ │ │
│ Topological sort Each room gets:
│ into parallel - channel.jsonl
│ waves - progress.json
│ - status file
▼ - memory ledger
Dependencies - lifecycle.json
between epics
  1. The Engine (Engine.ps1) parses your PLAN.md into structured epics
  2. A DAG resolves dependencies between epics and sorts them into execution waves
  3. Each epic gets a War-Room — an isolated directory with its own coordination files
  4. Agents are composed at runtime (Role + Skills + MCP tools) and execute inside their war-room
  5. A lifecycle state machine governs each room’s progress: developing → review → fixing → passed/failed

Key Design Decisions

  • Filesystem coordination — JSONL channels, JSON status files, markdown plans. No database required. Git-friendly. Every agent can read/write with basic file I/O.
  • Scale on depth, not width — Instead of many shallow agents, OSTwin uses fewer agents with deep skill injection. Quality over quantity.
  • Config over code — Agents are defined by role.json + ROLE.md + SKILL.md, not Python classes. Non-engineers can modify agent behavior.
  • Ephemeral agents — No persistent agent processes. Each session is composed fresh from its role, skills, and tools. No state leaks between runs.

System Components

ComponentTechnologyPurpose
EnginePowerShellParses plans, builds DAG, orchestrates war-rooms, manages lifecycle
DashboardFastAPI + Next.jsReal-time monitoring, plan status, war-room inspection, memory search
BotTypeScriptConversational interface for plan management and agent interaction
MCP ServersPython (FastAPI)Tool providers scoped per war-room — filesystem, memory, channel ops
SkillsMarkdown (SKILL.md)Portable domain expertise loaded into agent context on demand
RolesJSON + MarkdownAgent identity definitions — personality, constraints, allowed skills

What OSTwin is NOT

  • Not an agent framework — You don’t write agents. You write plans and roles.
  • Not a prompt chain — Agents make autonomous decisions within their war-room scope.
  • Not a wrapper around one LLM — Provider-agnostic. Works with Anthropic, OpenAI, Google, or local models.
  • Not a chatbot — There is no conversational loop. Plans go in, artifacts come out.

Who is OSTwin For?

  • Teams using AI for software engineering — automate entire feature development cycles
  • Platform engineers — build internal tooling around composable agent primitives
  • AI researchers — experiment with multi-agent coordination without framework lock-in
  • Solo developers — get an entire engineering team (architect, engineer, QA) from a single plan file

Next Steps

Ready to install? Head to Installation to get OSTwin running locally.