> ## Documentation Index > Fetch the complete documentation index at: https://writz.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Phases # Phases Four phases, one goal: the first trustless, private Bitcoin lending protocol on Stellar. ``` Phase 0 Phase 1 Phase 2 Phase 3 Research ──► Foundation ──► Launch ──► Scale ✅ COMPLETE 🔄 CURRENT Q4 2026 2027 ``` *** ## Phase 0 — Research & Validation ✅ COMPLETE **Goal:** Understand the technical landscape deeply enough to make confident architecture decisions.\ **Timeline:** June 2026\ **Status:** All 15 research documents produced. All architecture decisions validated. ### Key Findings * Stateless SPV on Soroban is feasible: \~37–55M instructions per full verification — within the 100M instruction budget * Protocol X-Ray (Protocol 26) BN254 host functions reduce ZK verification cost significantly * P2WSH locking script design complete and tested on Bitcoin Signet * SCF Build Award strategy defined (\$92K, Open Track, one-time application) ### Research Produced | Document | Key Finding | | ----------------------------------------------------------------------- | ------------------------------------------------------------------ | | [Bitcoin SPV on Other Chains](../research/spv-implementations.md) | summa-tx is the reference; stateless SPV avoids relayer dependency | | [Protocol X-Ray Deep Dive](../research/protocol-x-ray-capabilities.md) | Circom + Groth16 on BN254 is production-ready today | | [Soroban Compute Benchmarks](../research/soroban-compute-benchmarks.md) | Full deposit fits in one transaction | | [Bitcoin Locking Script](../research/bitcoin-locking-script.md) | P2WSH + CLTV design complete; Taproot in Phase 2 | | [Market Landscape](../research/market-landscape.md) | 28x growth in BTCfi; Stellar has zero BTCfi competition | | [Interest Rate Model](../research/interest-rate-model.md) | Kinked curve: Uoptimal=75%, slope2=200% | | [Liquidation Mechanism](../research/liquidation-mechanism.md) | ZK undercollateral proof; 150% min, 120% threshold, 10% bonus | | [Circom Circuit Design](../research/circom-circuit-design.md) | Three circuits; Groth16 trusted setup required pre-mainnet | | [Tokenomics & Fee Model](../research/tokenomics-fee-model.md) | Real-yield model; WRTZ token after \$5M TVL | | [Security Audit Strategy](../research/security-audit-strategy.md) | Audit Bank covers costs; Veridise for ZK circuits | *** ## Phase 1 — Foundation 🔄 CURRENT **Goal:** Working Bitcoin SPV client on Soroban testnet. SCF application submitted. Community presence established.\ **Timeline:** July–September 2026\ **Milestone:** SPV contract verified on testnet + SCF Tranche #0 received ### What's Complete ✅ | Item | Details | | ---------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------- | | **bitcoin-spv contract** | 28/28 tests. SHA256d, Merkle proofs, PoW validation. Deployed: `CAE5L7BO2GNF7MIZWXB2BTUMLYNIMQZUSWN2BWLZQS7HRHLOUSL6VLWJ` | | **zk-verifier contract** | 18/18 tests. Groth16 BN254 via Protocol 26 host functions. All 3 VKs set. Deployed: `CDV45GLXG4AOU6BDZSY5YHHVNGQIAYAPD3PUGXIIIYLIO6V2XGO6SMFV` | | **commitment-tree contract** | 50/50 tests. Full ZK cycle verified on-chain. Deployed: `CDFAP3J4WLFZC2N5U66X5EO62POBBIBXOKCCMCM3IRLJNXT73C4IBKA7` | | **private-lend contract** | 50/50 tests. Non-ZK skeleton with kinked interest model. Deployed: `CCLH2GJYG3QSHZJI7V7VK3DNMNK3I3QJCECBSFGX3AC6CK4I7EF7ZJ2G` | | **ZK circuits** | 45/45 tests. All 3 circuits compiled (Circom 2.2.3). Dev keys generated. | | **Relayer service** | 35/35 tests. REST API: `GET /spv-proof/:txid`. Esplora-backed. | | **Bitcoin script toolkit** | 48/48 tests. P2WSH generation, PSBT signing, witness assembly. | | **Bitcoin Signet E2E** | Path A co-signed release broadcast and accepted. `11932100` | | **ZK testnet E2E** | Full deposit→borrow→repay cycle on Soroban testnet. 6 transactions. `8daddf52` | | **SCF application** | Content complete: full application, 4-tranche milestone plan, STRIDE threat model | | **Documentation** | Complete rewrite: 22 documents across introduction, products, how-it-works, developers, security, roadmap | ### What Remains | Item | Status | | ------------------------------------- | ----------------------------------------------------------------------- | | Protocol 27 monitoring (July 8, 2026) | Monitor testnet; update co-signing key architecture after P27 ships | | Push repo public | Ready — waiting for community engagement first | | Mintlify docs at docs.writz.io | Connect GitHub → publish (mint.json ready) | | Demo video (testnet) | Record after docs are live | | Community engagement | Discord, GitHub discussions, Stellar forum — 2–3 weeks | | SCF referral | Approach Stellar ecosystem members after community presence established | | SCF application submission | After above checklist is complete | | Trusted setup ceremony — planning | Identify 5+ independent participants | ### Phase 1 Exit Criteria * [x] SPV contract verifies a real Bitcoin transaction on Soroban testnet ✅ * [x] P2WSH locking and release tested E2E on Bitcoin Signet ✅ * [x] ZK commitment-tree full cycle verified on Soroban testnet ✅ * [ ] SCF application submitted * [ ] Trusted setup ceremony planned and participants identified * [ ] SCF Tranche #0 received (\~\$9,200) *** ## Phase 2 — Launch *(Q4 2026)* **Goal:** Mainnet launch of PrivateLend v1 with real BTC collateral and ZK-private USDC loans.\ **Milestone:** First real mainnet deposit + first ZK-private USDC loan issued against real BTC ### Remaining Work **Protocol 27 integration (July 2026):** * Update co-signing key architecture using `delegate_account_auth` * Update SDK imports (breaking change in `@stellar/stellar-sdk`) **ZK circuits — production prep:** * Trusted setup ceremony: Powers of Tau Phase 2 for all 3 circuits * Publish ceremony transcript publicly * Recompile liquidation circuit artifacts after `usdc_debt` signal addition **Audit Bank:** * Submit intake form (after SCF Build Award received) * Readiness review (\~4 weeks) * Veridise audit: ZK circuits * OtterSec/Zellic audit: Soroban contracts * Remediate all Critical/High/Medium findings **Frontend (app.writz.io):** * Deposit flow UI: connect Xverse → P2WSH → SPV proof → ZK commitment * Borrow/repay UI with local position decryption * Position dashboard (health factor, interest accrued) * `/stats` public dashboard: TVL, utilization, protocol revenue * Stellar Wallets Kit integration (Freighter, Lobstr, others) * WASM ZK prover in browser (no server-side proving) **Mainnet launch (gated):** * TVL cap: $50,000 (raised to $250K after 30 days clean operation) * Whitelist-only for first 30 days * Protocol fee: 0% for 90-day bootstrap period * Protocol-owned USDC seed: \$50,000 * DeFiLlama submission (day 1) * Points program launch (pre-WRTZ) ### SCF Tranche Delivery | Tranche | Amount | Deliverable | | -------- | ---------- | ---------------------------------------------- | | #0 (10%) | \~\$9,200 | Phase 1 milestone: SPV on testnet | | #1 (20%) | \~\$18,400 | commitment-tree on testnet with ZK E2E | | #2 (30%) | \~\$27,600 | Circuits + trusted setup + frontend on testnet | | #3 (40%) | \~\$36,800 | Mainnet live, first real deposit | ### Phase 2 Exit Criteria * [ ] Mainnet deployment with passing Audit Bank audit (0 critical findings) * [ ] 10+ real deposits processed with no security incidents * [ ] \$50K TVL cap reached * [ ] TVL cap raised to \$250K after 30 days clean operation * [ ] Open-source SPV SDK published (GitHub + npm) * [ ] DeFiLlama listing live * [ ] All SCF tranches delivered *** ## Phase 3 — Scale *(2027)* **Goal:** \$10M TVL, WRTZ token launch, full product suite, Stellar ecosystem alliance.\ **Timeline:** Q1–Q4 2027 ### Product Expansion **Dark Swap (Q2 2027):** Private BTC-to-USDC conversions using the existing SPV infrastructure. AMM-style USDC liquidity. No exchange account, no visible order book. **BTC Savings (Q3 2027):** BTC collateral + automated USDC yield routing to Blend, Phoenix DEX, and other vetted Stellar protocols. **ZK Proof of Reserve — B2B (Q3 2027):** Enterprise attestation product. Direct sales. Target: 5 paying customers by end of 2027. See [ZK Proof of Reserve](../products/zk-proof-of-reserve.md). ### TVL Progression | Quarter | TVL Cap | | ------- | ---------- | | Q1 2027 | \$1M | | Q2 2027 | \$5M | | Q3 2027 | \$20M | | Q4 2027 | Remove cap | ### WRTZ Token (Q2–Q3 2027) **Launch criteria:** \$5M TVL sustained 60+ days, 500+ active wallets, one completed Audit Bank audit.\ **Structure:** Fair IDO / Liquidity Bootstrapping Pool — no VC cliff dumps.\ **Real-yield mechanics:** Protocol revenue used to buy and burn WRTZ.\ **Governance:** TVL cap increases, fee adjustments, insurance fund payouts, new product whitelisting. ### Stellar Ecosystem Alliance * Contribute Writz SPV SDK as Stellar ecosystem infrastructure * Propose a SEP standard for Bitcoin SPV on Stellar * Co-market with SDF as the flagship BTCfi protocol on Stellar * Apply for SCF Growth Hack Program (after 60+ days mainnet, completed audit, no active SDF grants) * Apply for SCF Liquidity Award (after \$250K TVL sustained 7 days) ### Wallet Integrations Target integrations with demonstrated traction and open SDK: * Xverse: BTC DeFi section with PrivateLend * Freighter: BTC collateral option in the lending section * Lobstr: BTC yield product in the savings section ### Institutional BD * Direct outreach to crypto hedge funds, family offices, BTC mining companies * Compliance documentation package (ASP attestations, audit reports, regulatory positioning) * Target: 3–5 institutional deposits of \$100K+ each *** ## Success Metrics | Phase | Metric | Target | | ------- | ------------------------------------- | ------ | | Phase 1 | SPV verifications on testnet | 100+ | | Phase 1 | SCF application submitted | ✓ | | Phase 2 | Mainnet TVL (day 30) | \$50K | | Phase 2 | Mainnet TVL (day 90) | \$250K | | Phase 2 | Audit completed (0 critical findings) | ✓ | | Phase 2 | DeFiLlama listed | ✓ | | Phase 3 | TVL | \$5M+ | | Phase 3 | Monthly protocol revenue | \$15K+ | | Phase 3 | Protocols using SPV SDK | 3+ | | Phase 3 | Proof of Reserve customers | 5+ | | Phase 3 | WRTZ token launched | ✓ | *** **See the full vision:** [Vision →](vision.md)