Executive Summary
The CKB Anywhere Card is a browser extension that allows CKB holders to spend directly anywhere Visa/Mastercard is accepted globally across 60 million merchants in 210 countries enabling payments on platforms that don’t accept crypto currencies.
Unlike traditional crypto cards that require users to surrender custody and pre-load funds 24–48 hours in advance, it uses Just-In-Time (JIT) liquidity. By leveraging JoyID and UTXOSwap, the extension generates a single-use virtual card at the exact moment of purchase, eliminating pre-funding while preserving full user control.
This proposal seeks a development grant to build the extension and seed a DAO-governed revolving liquidity facility, establishing CKB as the premier Spend Layer for the UTXO ecosystem.
Funding Request
| Component | Amount | Purpose |
|---|---|---|
| Development Grant | $20,000 | Plugin build, CKB integration, security audit, launch |
| Community Liquidity Facility | $50,000 | DAO-governed revolving fiat float |
| Total | $70,000 | payable in CKB |
1. Project Overview
The system enables real-time spending by combining non-custodial authorization (JoyID), on-demand liquidity (UTXOSwap), and a DAO-governed liquidity facility. At the moment of purchase, the extension coordinates these components to authorize a card transaction instantly while the underlying CKB swap settles asynchronously.
No pre-loading. No centralized custody. No KYC required.
This proposal funds the CKB-native integration layer and seeds the community liquidity facility that makes zero-latency authorization possible.
2. The Problem: The Liquidity Gap
CKB is architecturally optimized as a Store of Value but its utility as a Medium of Exchange is throttled by friction.
Existing card solutions share the same fundamental flaw: they require users to pre-load funds into a centralized account 24–48 hours in advance. This forces users to trust a third party with their capital and strips them of optionality during that window.
This friction is the single biggest barrier between Nervos holders and real-world utility. For a network built around the Store of Value thesis, this is the missing piece. A currency that cannot be spent without friction is not completing its loop.
3. The Solution: Just-In-Time (JIT) Spending
At checkout, the user clicks the plugin. It detects the payment form, calculates the real-time CKB amount, and triggers a JIT flow that generates a virtual card, and auto-fills details all within seconds.
Your CKB stays in self-custody until the moment of purchase. The community float covers the instant Visa/Mastercard authorization, while the on-chain UTXOSwap settles asynchronously in the background ensuring the user never waits for a block confirmation to complete their purchase.
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The Plugin: A browser extension that auto-detects standard checkout fields on any website (Amazon, Uber, etc.) and triggers the JIT card generation flow.
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The Nervos Liquidity Facility: A $50,000 community-owned revolving float governed by Nervos DAO stewards via multi-sig. It pre-funds the Zebec/Lithic issuing balance for zero-latency card authorization. It is never spent it is collateral that revolves with every transaction.
| Feature | Legacy Crypto Cards | CKB Anywhere Card |
|---|---|---|
| Custody | Centralized / Pre-loaded | Non-Custodial (JoyID) |
| Wait Time | 24–48 Hours to Top-up | Instant (JIT) |
| Privacy | Full KYC required | No KYC (<$1k via Zebec) |
| Asset Usage | Locked in Card Wallet | Staked/Liquid in CKB until spent |
4. Technical Specification: The Logic
The CKB Anywhere Card is built on a four-tier architecture: the Client Extension, the Nervos Integration Layer, the Middleware API, and the Card Issuing Rail.
4.1 The JIT Execution Flow
To ensure zero-latency at checkout while maintaining non-custodial security, the following logic is executed within seconds of the user clicking “Pay with CKB”:
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Field Detection: The extension uses a DOM observer to identify standard ISO 7812 payment fields (Card Number, CVV, Expiry) on the merchant’s site.
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Quote Retrieval: The Middleware calls the UTXOSwap API to get a real-time intent-based quote for the required CKB/USD pair, including a 1–2% volatility buffer.
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JoyID Authorization: The user is prompted for a biometric signature via the
@joyid/ckbSDK. This signature authorizes the specific Cell consumption for the swap. -
Float-Backed Issuance: Upon signature verification, the Middleware triggers a POST request to the Zebec Silver API (
/createSilverCard) or Lithic API (/v1/cards) to provision a single-use virtual card. -
Payload Injection: The extension auto-fills the generated card details into the merchant’s checkout form via secure content scripts.
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Asynchronous Settlement: While the merchant processes the Visa/Mastercard transaction, the user’s signed CKB transaction is broadcast to Nervos L1 to replenish the Liquidity Facility.
4.2 Why CKB is the Natural Settlement Rail
Unlike account-based chains (EVM), CKB’s Cell Model is architecturally optimised for high-concurrency, low-overhead transaction patterns, exactly what JIT spending requires.
Each purchase is executed as an intent-secured cell transaction; the user’s CKB is released only if the swap routes to the liquidity facility’s address. If the swap fails, the transaction is rejected, and the card is never issued. The $50,000 community float is never exposed to unfilled swaps.
What makes CKB the natural fit isn’t atomicity alone; other UTXO chains support that. It’s the combination of:
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Cell Model composability: lock scripts define precise spending conditions without global state contention.
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Low per-cell overhead: small, frequent transaction cells settle with minimal cost, suited to real-time card authorization volumes.
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Native UTXO ecosystem position: as the settlement layer for Rosen Bridge, CKB is already the connective tissue between UTXO chains, making it the logical base for a multi-chain spend layer.
No rebuild is required as the system scales. The architecture that handles a single JIT transaction handles thousands and eventually, assets from any connected chain are routed through CKB settlement.
5. Provider Status & KYC
We are in active integration discussions with Zebec and Lithic, with SDK access and sandbox testing as the immediate next steps.
Zebec is the primary provider, offering prepaid single-use virtual Mastercard issuance with no KYC required for transactions under $1,000. These cards are accepted across 60 million merchants in over 210 countries and require no legal documentation for basic usage.
Lithic is the secondary provider, offering scalable and compliant card issuance infrastructure designed for programmatic virtual card generation.
Deployment of the liquidity facility will proceed upon confirmation of provider capabilities and successful sandbox validation.
6. Liquidity Facility: Float Custody & Governance
The $50,000 liquidity facility is not a development expense it is a revolving, DAO-controlled community asset.
Transaction flow:
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User initiates a purchase via the plugin
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Float instantly covers the card authorization for the Visa/Mastercard network
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User’s CKB is simultaneously swapped via UTXOSwap to replenish the float
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Float returns to full capacity, ready for the next transaction
The Kill Switch DAO stewards reserve the right to revoke the plugin’s access to the liquidity facility at any time ensuring the community can protect funds immediately if a provider or the plugin is ever compromised.
Custody & Governance
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Controlled by a Nervos DAO multi-sig
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Signatories are appointed DAO stewards
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All replenishment transactions are publicly verifiable on-chain
Risk Management
| Risk | Mitigation |
|---|---|
| Card provider disruption | Zebec is the primary rail from day one. Lithic is the named secondary provider purpose-built for single-use virtual card issuance with direct Visa/Mastercard network integration. The plugin architecture is provider-agnostic; no rebuild is required to switch rails. The float remains intact during any provider transition. |
| CKB price volatility | A 1–2% slippage buffer is built into every UTXOSwap, covering the gap between card authorization and on-chain settlement. |
| Float security | The float never touches the plugin it stays in the Zebec/Lithic issuing account. The plugin sends an “Authorize” command only after a valid on-chain JoyID signature is confirmed. |
| Regulatory & network risk | Changes to card network or provider policies could affect the availability of virtual card issuance. Mitigated by the provider abstraction layer (Zebec/Lithic), jurisdictional flexibility, and modular architecture enabling rapid migration without impacting user funds or float integrity. |
| Swap broadcast failure | If a signed CKB transaction fails to broadcast after card issuance, the float absorbs the shortfall. Repeated failures trigger an automatic spending threshold pause controlled by DAO stewards until the cause is resolved. All transaction signing and broadcast events are logged by the middleware for auditability. |
7. Development Roadmap & Milestones
Total Dev Budget: $20,000 USD (payable in CKB)
| Milestone | Deliverable | Timeline | Disbursement |
|---|---|---|---|
| 1 — Prototype | Extension scaffold, Zebec API integration, CKB Testnet demo | Month 1 | $10,000 |
| 2 — Beta | UTXOSwap integration, slippage engine, invite-only beta (50 users) | Month 2 | $10,000 |
| 3 — Launch | Security audit report, public release, DAO multi-sig setup, float deployment | Month 3 | $50,000* |
*The $50,000 is a community asset moved into production, not a fee paid to developers.
Milestone 1 — The Foundation (Month 1)
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Functional Chrome/Firefox extension UI detecting standard payment fields
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Secure API middleware connecting to Zebec for card provisioning
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Successful mock transaction on CKB Testnet using JoyID signing
Milestone 2 — The Integration (Month 2)
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UTXOSwap integration for automated CKB-to-stablecoin routing at point of sale
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Slippage engine with 1–2% buffer logic protecting the float from market volatility
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Release candidate distributed to 50 whitelisted community members
Milestone 3 — The Go-Live (Month 3)
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Security audit report covering non-custodial key handling and API security
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DAO multi-sig setup and $50k float handover to production Zebec issuing account
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Public deployment to Chrome Web Store and Firefox Add-ons gallery
8. The CKB Spend Layer
The architecture is being planned with CKB serving as the UTXO payment rails. This creates a multi-chain foundation: once Rosen Bridge matures, the plugin and liquidity facility will serve holders of any connected asset. By routing cross-chain swaps through CKB settlement, Nervos becomes the universal payment infrastructure for the broader UTXO ecosystem.
9. Why This Matters for Nervos
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Real-world utility at global scale: 60 million merchants, 210 countries, from day one
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The float is a permanent community asset: $50,000 governed by the DAO indefinitely, not a grant that gets consumed
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Completes the CKB value loop: holders can earn, save, stake, and spend without ever leaving the ecosystem
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Proven Cell Model utility: demonstrates CKB’s architecture is purpose-built for high-concurrency, real-world financial applications
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Foundation for the Spend Layer vision: Phase 1 proves the model; Rosen Bridge and Fiber Network enable UTXO ecosystem expansion
10. About Build Union
Build Union is an independent development collective with full-stack coverage across Solidity, CKB-VM, frontend development, product design, and DeFi research.
Lead Product Specialist — E.Eclipse [ Former product lead at Dash Incubator. Currently delivering The Shield for Polkadot ($2B TVL environment), with existing multichain development work including Nervos.
[讨论] CKB Anywhere Card：Nervos 的即时支付层（JIT Spend Layer）
执行摘要
CKB Anywhere Card 是一款浏览器扩展程序，允许 CKB 持有者在全球 210 个国家、6000 万家接受 Visa/Mastercard 的商户直接消费, 在不接受加密货币的平台上实现支付
与传统的加密货币卡（要求用户交出托管权并提前 24-48 小时充值）不同，它采用即时（Just-In-Time, JIT）流动性技术。通过利用 JoyID 和 UTXOSwap，该扩展程序在支付的瞬间生成一张一次性虚拟卡，在保留用户完全控制权的同时，消除了预充值的需求。
本提案申请一项开发赠款用于构建该插件，并资助一个由 DAO 管理的循环流动性设施，旨在将 CKB 打造为 UTXO 生态系统的首选支付层。
资金申请
| 组件 | 金额 | 用途 |
|---|---|---|
| 开发赠款 | $20,000 | 插件构建、CKB 集成、安全审计、上线 |
| 社区流动性设施 | $50,000 | DAO 管理的循环法币备用金 |
| 总计 | $70,000 | 以 CKB 支付 |
1. 项目概述
该系统通过结合非托管授权（JoyID）、按需流动性（UTXOSwap）和 DAO 管理的流动性设施来实现实时消费。在支付瞬间，扩展程序协调这些组件即时授权卡交易，而底层的 CKB 兑换则在后台异步结算。
无需预充值、无中心化托管、无需 KYC。
本提案资助 CKB 原生集成层的开发，并为实现零延迟授权的社区流动性设施提供种子资金。
2. 问题所在：流动性缺口
CKB 在架构上被优化为价值存储（Store of Value），但其作为交换媒介（Medium of Exchange）的效用因摩擦过大而受阻。
现有的支付卡解决方案都有一个共同的缺陷：要求用户提前 24-48 小时将资金预充到中心化账户中。这迫使用户将资金信任于第三方，并在充值窗口期内失去了操作的灵活性。
这种摩擦是 Nervos 持有者通往现实世界应用的最大障碍。对于一个围绕价值存储理论构建的网络来说，这是缺失的一环。无法无缝消费的货币无法完成其生态闭环。
3. 解决方案：即时（JIT）消费
在结账时，用户点击插件。它会自动识别支付表单，计算实时的 CKB 金额，并触发 JIT 流程生成虚拟卡并自动填充详细信息——整个过程在几秒钟内完成。
您的 CKB 在购买发生前一直处于自托管状态。社区备用金先行覆盖 Visa/Mastercard 网络的即时授权，而链上 UTXOSwap 在后台异步结算，确保用户无需等待区块确认即可完成购买。
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扩展插件： 一个浏览器扩展程序，自动检测任何网站（如 Amazon、Uber 等）的标准结账字段，并触发 JIT 购卡流程。
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Nervos 流动性设施： 一个价值 $50,000 的社区共有循环备用金，由 Nervos DAO 管理员通过多签治理。它为 Zebec/Lithic 发卡余额提供预置资金，以实现零延迟授权。这笔资金不会被耗尽，而是随着每笔交易循环使用的抵押品。
| 功能 | 传统加密货币卡 | CKB Anywhere Card |
|---|---|---|
| 托管方式 | 中心化 / 预充值 | 非托管 (JoyID) |
| 等待时间 | 24–48 小时充值期 | 即时 (JIT) |
| 隐私性 | 需要完整 KYC | 无需 KYC (通过 Zebec <$1k) |
| 资产用途 | 锁在卡钱包中 | 在消费前一直处于 CKB 质押/流动状态 |
4. 技术规范：逻辑原理
CKB Anywhere Card 建立在四层架构之上：客户端扩展、Nervos 集成层、中间件 API 和发卡通道。
4.1 JIT 执行流程
为确保结账时的零延迟并保持非托管安全性，在用户点击“使用 CKB 支付”后的几秒内将执行以下逻辑：
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字段识别： 扩展程序使用 DOM 观察器识别商户网站上的标准 ISO 7812 支付字段（卡号、CVV、有效期）。
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报价获取： 中间件调用 UTXOSwap API 获取所需的 CKB/USD 交易对实时意图报价，包括 1-2% 的波动缓冲。
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JoyID 授权： 系统提示用户通过 @joyidjoyidjoyidjoyidjoyidjoyidjoyidjoyid/ckb SDK 进行生物识别签名。该签名授权用于兑换的具体 Cell 消耗。
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备用金担保发卡： 签名验证后，中间件触发向 Zebec Silver API 或 Lithic API 发送请求，配置一张一次性虚拟卡。
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数据注入： 扩展程序通过安全内容脚本将生成的卡信息自动填充到商户的结账表单中。
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异步结算： 在商户处理 Visa/Mastercard 交易的同时，用户签名的 CKB 交易被广播到 Nervos L1，以补充流动性设施。
4.2 为什么 CKB 是天然的结算层
与基于账户的模型（EVM）不同，CKB 的 Cell 模型在架构上针对高并发、低开销的交易模式进行了优化，这正是 JIT 消费所需要的。
每笔购买都作为意图担保的 Cell 交易执行；只有当兑换路径成功指向流动性设施地址时，用户的 CKB 才会释放。如果兑换失败，交易被拒绝，卡片绝不会签发。这确保了 $50,000 的社区备用金不会暴露在未完成的兑换风险中。
5. 服务商状态与 KYC
我们正在与 Zebec 和 Lithic 进行积极的集成讨论。
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Zebec 是首选服务商，提供单次使用的预付虚拟万事达卡，1,000 美元以下的交易无需 KYC。
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Lithic 是备选服务商，提供可扩展的合规发卡基础设施。
6. 流动性设施：备用金托管与治理
这 $50,000 流动性设施不是开发费用，而是循环的、DAO 控制的社区资产。
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风险管理： 包含 1-2% 的滑点缓冲以应对 CKB 价格波动；如果 CKB 交易广播失败，备用金将吸收差额并触发自动熔断。
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治理： 由 Nervos DAO 多签控制，所有资金补充交易在链上公开可查。
7. 开发路线图与里程碑
总开发预算：$20,000 USD（以 CKB 支付）
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里程碑 1：原型阶段（第 1 个月）- $10,000
- 插件原型、Zebec API 集成、CKB 测试网演示。
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里程碑 2：Beta 阶段（第 2 个月）- $10,000
- UTXOSwap 集成、滑点引擎、50 名用户内测。
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里程碑 3：上线阶段（第 3 个月）- $50,000（流动性注入）
- 安全审计、正式发布、DAO 多签设置、备用金部署。
8. CKB 支付层愿景
该架构以 CKB 作为 UTXO 支付轨道。随着 Rosen Bridge 的成熟，该插件和流动性设施将服务于任何连接资产的持有者。通过 CKB 进行跨链结算，Nervos 将成为广义 UTXO 生态系统的通用支付基础设施。
9. 为什么这对 Nervos 至关重要
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全球规模的现实应用： 第一天即可在 6000 万商户使用。
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永久社区资产： $50,000 由 DAO 无期限治理，而非消耗性开支。
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完成 CKB 价值闭环： 持有者无需离开生态即可赚取、储蓄、质押和消费。
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证明 Cell 模型效用： 展示 CKB 架构在真实金融场景中的高并发能力。
10. 关于 Build Union
Build Union 是一个独立的开发集体，涵盖 Solidity、CKB-VM、前端开发和 DeFi 研究。
首席产品专家：E.Eclipse —— 前 Dash Incubator 产品负责人，目前正在交付 Polkadot 生态的 The Shield 项目（20 亿美元 TVL 环境）。