Bitcoin SPV inside a Soroban contract, in one picture.
The contract does not call a Bitcoin node.
The caller brings 6 headers, a Merkle proof, and the raw transaction.
The contract checks the math.
The testnet app is public.
What works today is on the site. What does not work yet is also on the site.
We will not paper over that.
Site: writz.xyz
App: testnet.writz.xyz/
Docs: docs.writz.xyz/docs/architecβ¦
Code: github.com/WritzProtocol/wriβ¦
Do you know what Writz is?
Come say hi to us during HackMeridian and Meridian.
We love connecting with the community!
What if you could borrow USDC without selling your Bitcoin?
Writz is a BTC-backed lending protocol on blockchain with no bridging, wrapping or custodians, so your BTC stays on Bitcoin. Meet the team at HackMeridian π΅πΉ @WritzProtocol
Presidente @nayibbukele, le escribimos con una propuesta concreta.
Somos Writz Protocol, una startup de cuatro latinoamericanos, de Costa Rica y Colombia, que construye infraestructura financiera para Bitcoin sobre Stellar.
El dato que nos trae aquΓ: El Salvador mantiene una reserva de mΓ‘s de 7,800 BTC, cerca de US$650 millones a precio de hoy. Y el paΓs estΓ‘ invirtiendo en grande: al 14 de agosto, Dos Escuelas por DΓa sumaba 900 centros escolares intervenidos y US$858 millones invertidos.
Writz permite usar bitcoin como garantΓa sin venderlo:
- El BTC nunca sale de la red Bitcoin. Queda bloqueado en un script que nadie puede mover por su cuenta. Sin custodio, sin puentes, sin tokens envueltos.
- Un contrato en Stellar verifica ese bloqueo contra la propia cadena de Bitcoin y entrega dΓ³lares digitales (USDC).
- Al pagar, el BTC se libera. Si el protocolo dejara de existir, el dueΓ±o recupera su BTC por sΓ solo al vencer el plazo.
Un ejemplo con nΓΊmeros: 100 BTC, con una garantΓa conservadora del 200%, respaldan unos US$4.2 millones en USDC. Eso equivale a cuatro escuelas al costo promedio del programa.
Por eso queremos ofrecerle firmar una carta de intenciΓ³n no vinculante (LOI) para diseΓ±ar un piloto: liquidez en stablecoins para seguir invirtiendo en escuelas, agua y electricidad, sin que el paΓs venda su bitcoin. Hoy estamos en testnet, con lanzamiento en mainnet previsto para 2027 tras una auditorΓa externa.
AyΓΊdanos a que esta propuesta llegue a la mesa:
1. Dale repost.
2. Comenta mencionando a @nayibbukele y @PresidenciaSV .
#ElSalvador #Bitcoin
Privacy on Writz, without the slide version.
We have ZK work on testnet. We will not say your position is hidden on mainnet until that is the product you can click.
Two contracts, on purpose. One is a non-ZK lending path. One is a commitment-tree path with Groth16.
They were built to be separable. Launch order is a product decision. It is not a post.
Architecture: docs.writz.xyz
What we are actually building.
The core is BTC-collateral lending on Stellar: SPV in, USDC out.
In parallel, Instaward 1 is a scoped USDC Earn sprint. That sprint is not a rebrand of Writz.
Most lending protocols publish your collateral, your debt, and how close you are to liquidation.
Should a DeFi position be a public billboard?
Wrapped BTC is an IOU.
A good IOU is still an IOU. An issuer holds BTC and mints a token on another chain.
Writz is a script on Bitcoin and a verifier on Soroban. The collateral never becomes a token named BTC.
How the BTC gets locked.
A P2WSH output on Bitcoin. Two paths out. Only two.
Path A: you and the protocol sign.
Path B: the timelock expires, you sign alone.
The relayer is public on testnet: api.testnet.writz.xyz
Give it a txid. It returns the headers and the proof shaped for the call.
Docs: docs.writz.xyz
Your Bitcoin never leaves Bitcoin. Your loan, nobody sees.
Real BTC collateral, verified on-chain via SPV. Zero custodians. ZK-private positions.
Your keys. Your coins. Your loans.
Writz Protocol π Meridian 2026 π΅πΉ retweeted
Proof of win π₯
Had the privilege of pitching @WritzProtocol in BogotΓ‘ at Pulso Hackathon Colombia π¨π΄ and we won 1st place!
This unlocked:
βοΈ A trip to SΓ£o Paulo for the Stellar Builder Summit
π° Funding through Instawards program to keep building
Proud of this team β‘οΈ
Writz Protocol lets you lock real BTC from a Bitcoin wallet and borrow USDC on Stellar.
No bridge.
No custodian.
No wrapped token.
A short thread on what that means, what we have already shipped, and where to read the code.
What you can open today:
Site and testnet app: writz.xyz
Docs: docs.writz.xyz
Code (Apache-2.0): github.com/WritzProtocol/wriβ¦
Testnet. Not mainnet. We will say mainnet when mainnet is true.










