The AI Operating System for Physical Businesses. One brain (Momo). Two services (Saros + Melody). One data layer (KinTwin). One protocol (Zeus).

We're not building an AI company. We're building an AI OS that runs companies.

每一个Agent都是一个操作系统。不是"用了AI的公司"——是每一个细胞都是AI的公司。

📖 Read this document in: [English (current)] | 中文

YC Summer 2026 AI Operating System AI-Native Service AI Personalized Medicine Software for Agents Company Brain Offline Physical Health Infrastructure

1 node · 7 years · 118 active members · 9 AI Agents · 24/7 autonomous · 5 YC RFS directions

30-Second Elevator Pitch

ZWISERFIT is an AI OS for companies, built from 9 vertical Company Brain Agents. The front-end delivers two AI-native services: Saros store digital co-founder solves Planet Fitness' labor cost problem; Melody personal metabolic coach manages energy, glycolipid, and hormonal health in three dimensions. The bottom layer, KinTwin, captures hardware-verified continuous behavior streams — more objective and unforgeable than Nourish's self-reported data. All encrypted assets flow through Zeus Protocol to insurance institutions for dynamic risk pricing. Five YC RFS directions covered in one company.

ZWISERFIT 是一套由 9 大垂直领域 Company Brain 组成的企业级 AI 操作系统。前端两套 AI 原生服务：Saros 门店数字合伙人，帮 Planet Fitness 这类连锁健身房重构人力成本；Melody 个人代谢管理教练，帮会员实现能量+糖脂+激素三维代谢管理。底层 KinTwin 连续行为流基础设施对标 Nourish，但数据来自线下门店——更连续、更客观、不可伪造。全部加密资产通过 Zeus 协议栈对接保险机构，实现动态风险定价。一次覆盖 YC 五条赛道。

💰 For Investors: Deck → · Live Data ↓ · Core Moats ↓ 🏪 For Gym Owners: Saros Open → · Deployment docs 🤖 For AI / Protocol Developers: KinTwin SDK → · Zeus Specs → 📜 Founder Full Story (中文): → FOUNDER_STORY.md

Four $B+ companies. Four separate bottlenecks. One OS.

• Planet Fitness (2,795 locations): 40%+ of revenue goes to labor — eating 2/3 of profit.
• Life Time ($900M CAPEX): Right direction, wrong leverage — 500 coaches don't scale.
• Nourish ($215M raised): Proved insurers want health data — but data is self-reported. Unverifiable.
• WHOOP / Oura: Data belongs to the platform, not the user.

None of the four industry leaders owns the complete closed-loop pipeline: offline behavior collection → personalized metabolic intervention → cryptographic data asset confirmation → automated insurance risk pricing monetization. ZWISERFIT does. With one AI brain.

Most vertical fitness/health startups only build single-layer tools. ZWISERFIT is the first to integrate all five layers as one platform.

ZWISERFIT = YC RFS #15: AI Operating System for Companies — the only category that can carry all five layers as a single integrated platform.

Momo is one of the 9 Agent OSes — specifically, the Store O/S. She is the "brain" of Saros and Melody, not the commander of all 9 Agents. (Shuyu is the Strategy O/S that orchestrates the full kernel.) Two external faces for different users.

Momo（Store O/S · One of 9 Agent OSes inside the Company Brain kernel）
├── Saros → B2B：Store Digital Co-Founder（replaces store manager labor cost）
└── Melody → B2C：Personal Metabolic Coach（replaces nutrition coach headcount）

Momo is the vertical store-operation Company Brain within the 9-Agent kernel (YC #4). It is the unified cognitive engine powering both B2B Saros and B2C Melody, with separated execution interfaces for different user groups.

• For members: They only know "Momo." "Momo planned my workout" (Melody). "Momo checked me in" (Saros). They don't need to distinguish.
• For store owners: Momo runs the store as Saros — the B2B external interface built upon Momo's store operation kernel.
• For investors: Two independently-valuable business lines — B2B SaaS + B2C health management — running on the same kernel.

One brain, two faces, one brand. Members know "Momo" as their coach. Store owners know "Momo" as their store manager. Investors see two revenue lines on one kernel. This is not complexity. This is elegance.

Saros is the B2B external interface built upon Momo's store operation kernel.

Momo（Store O/S · Founder's cognitive encoding）
    +
SaaS Stack（POS / CRM / Scheduling / Membership / Inventory）
    =
Saros — 门店数字合伙人

Saros delivers end-to-end autonomous store operation — not just standalone SaaS tools for manual human operation. The AI runs the store; humans deliver warmth.

YC Direction #2: AI-Native Service — 2.5× profit per store by replacing the largest fixed cost: store manager labor.

GLP-1 is opening the floodgates. Millions are on weight-loss medications. But here's the paradox: without exercise, users lose muscle — not just fat. Muscle loss → lower basal metabolism → faster rebound after stopping → worse than before. Insurers are starting to pay for interventions that prevent this. The question is: whose data do they trust?

Melody manages metabolism across three layers, powered by the same Momo kernel:

"Women's hormonal lifecycle is systematically ignored as a core variable in cardiovascular disease risk modeling."

— American Heart Association, Circulation 2024 Official Scientific Statement

There is a 30% structural gap in health data infrastructure for women. Questionnaires cannot fill it. Wearables alone cannot fill it. It requires offline continuous behavior streams + metabolic biomarkers + hormonal cycle tracking — the exact three-dimensional pipeline that only KinTwin captures.

No competitor can replicate the offline hormonal cycle tracking pipeline.

YC Direction #2: AI-Native Service — zero marginal cost metabolic coaching, powered by the same Momo kernel.

Facial-recognition Gate ──→ Cameras ──→ Body Scanner
         │                      │              │
         └──────────────────────┴──────────────┘
                        │
              Hardware Root of Trust
                   (Physical Layer)
                        │
              Nova Continuous Behavior
                Stream Generation
                        │
              Ethan SHA-256 Notarization
                + Ownership Anchoring
                        │
              KinTwin — Crypto-verified
              Behavior Data Asset Pool

Nourish validated the demand — but it can never deliver the real answer. KinTwin delivers what insurers actually need: unforgeable continuous behavior streams with cryptographic proof. ✅ Stella Compliance Audit Verified

YC Direction #3: AI-Native Personalized Medicine — Angel round narrative entry point. The most tangible, investable wedge into the full platform story.

Internal 9-Agent Cluster
    │  Ethan hash ciphertext → unreadable to external agents
    │
    ├── Zeus ── Sole Authorized Oracle Decoder
    │           Actuarial data packets / Valuation interface / Asset credentials
    │
    ▼
External Agents (VC DD · Insurance Underwriting · Pharma Procurement)

GLP-1 is opening the floodgates for insurers to pay for health outcomes. Nourish proved insurers will pay for nutrition interventions. Zeus proves insurers will pay for exercise-verified health outcomes — and exercise can only be verified through offline, continuous behavior streams.

Revenue path:

PoPB (Proof-of-Behavior Protocol) — a cryptographic standard that proves "this person actually exercised" using hardware-verified, SHA-256 anchored behavior streams. Insurers verify physical facts, not user self-reports.

Distinction from Tristan Agent: Tristan maintains hardware and network physical transmission pipelines. Zeus exclusively defines actuarial data format, Agent handshake rules, and asset transaction state machines. Tristan guarantees connectivity; Zeus enables monetization.

YC Direction #12: Software for Agents

9 independent vertical brain OSes run in parallel. 24×7 self-scheduling, self-auditing, self-iterating.

Founder Suzanne Mok（Cognitive Origin）
    │  Decade of cross-domain frontline wisdom — irreplicable
    │
    ├── Strategy ──── Shuyu    Strategy O/S · Enterprise command
    ├── Store ─────── Momo     Store O/S · Physical operations (founder's family name "莫")
    │
    ├── Data ──────── Nova     Behavior Stream O/S · Continuous data generation
    │                 Ethan    Sovereignty O/S · Hash notarization + DID
    │
    ├── Protocol ──── Zeus     Capital Protocol O/S · External I/O gateway
    │
    ├── Operations ── Tristan  Infra O/S · Hardware + network transmission
    │                 Baron    Content O/S · Brand + narrative
    │                 Luna     Community O/S · Developer ecosystem
    │
    └── Audit ─────── Stella   Compliance O/S · Independent verification

9 OSes. One Kernel. Zero human operational overhead.

Each Agent is a complete, independently-running operating system — with its own scheduler, file system, external protocol stack, and self-iteration loop. The founder's decade of cross-domain frontline wisdom is encoded as the boot sector of every Agent OS.

YC Direction #4: Company Brain

#15 is the primary track. It is the only category that can carry all five layers — 9-Agent kernel + Saros app + Melody app + KinTwin data + Zeus protocol — as a single integrated platform. The other four directions map to specific modules inside the OS.

1. Hardware Root of Trust — Self-developed facial-recognition turnstile + cameras + body scanners. Data integrity starts at the physical layer, not the database. No software-only solution can replicate this.
2. 7 Years of Unforgeable Data — 380,000+ SHA-256 anchored behavior records from Dongguan Wanjiang, China's lowest fitness penetration. You can fork code. You cannot fork 7 years of continuous, cryptographically-verified behavioral data. Time is the only moat competitors can never compress.
3. Founder-Encoded OS — Each Agent OS boot sector was hand-coded with the founder's decade of cross-domain frontline wisdom — PwC audit × Ping An Life insurance pricing × 7 years gym operations × AI system creation. Not deployed. Not integrated. Born from real-world trial and error. No competitor can replicate this — not because they can't hire smart people, but because no one else has lived the full stack: audit × insurance pricing × gym operations × AI system design, in one person, over one decade.

莫淑瑜 (Suzanne Mok)

In 2017, the founder lost a family member to cancer — the same person who most opposed her entering insurance. She joined insurance to "put a financial firewall under every family." After the loss, she asked: what matters more — money or people? She left insurance. Started a gym in Dongguan Wanjiang — China's lowest fitness penetration. 7 years. One store. Through COVID, through losses, through debt. Not because she couldn't expand. Because she refused to expand before the OS was ready.

In 2025, she completed the full PRD defining every layer of what would become ZWISERFIT — before AI went mainstream. In 2026, she built 9 AI Agents by hand, replacing an estimated 26 weeks and millions in software engineering. She gave her own name to two Agents: Shuyu (Commander) and Momo (Store Manager, family name "莫").

The founder didn't catch up to AI. AI caught up to the blueprint she drew in 2025.

Her four identities — PwC auditor · Ping An Life Insurance 5 years (insurance pricing insider) · 7 years gym operations · AI system creator — are irreplicable. All 9 vertical Agent operating systems are built on the founder's exclusive cross-industry cognition covering offline venue operation, insurance underwriting and risk audit — a cognitive moat that cannot be replicated by competitors relying solely on technical algorithms. This is not a team. This is a cognitive origin.

The founder didn't use AI. She gave birth to it.

Read the full founder story (中文) →

Open the application layer to build ecosystem. Close the kernel and protocol to protect the moat. The moat isn't in code — it's in 7 years of data, hardware trust root, and time.

Legal Note: Saros, Melody, and KinTwin SDK are MIT-licensed. Zeus Protocol specification adopts CC BY-NC-ND 4.0. The 9-Agent kernel source code remains proprietary and closed.

New here? Start with /saros-open/ to deploy an AI store manager, or /investor for the full deck.

ZWISERFIT/
├── 🟢 saros-open/          MIT — Store digital co-founder (deploy to any gym)
├── 🟢 melody-open/         MIT — Metabolic coaching engine (integrate into your app)
├── 🟡 kin-twin-sdk/        SDK open — Hardware API + data format specs
├── 🔴 zeus-protocols/      Specs open (CC BY-NC-ND) — Agent communication standards
└── ⚫ 9-agent-kernel/      Docs only — Architecture + design philosophy

We welcome developers, venue operators, and researchers — especially to the open-source Saros and Melody layers.

1. 🐛 Found a bug? → Open an Issue
2. 💡 Have an idea? → Start a Discussion
3. 🔧 Ready to code? → Pick a Good First Issue

ZWISERFIT · Dongguan, Guangdong, China AI + Human Synergy. Users own their data.

📄 MIT