diff --git a/CLAUDE.md b/CLAUDE.md
index 103df11..21438fb 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -4,62 +4,84 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Commands
 
-### Build
+### Solana Programs (Rust)
 
 ```bash
-# Build a single program (produces .so in target/deploy/)
-cargo build-sbf --manifest-path programs/descro/Cargo.toml
-cargo build-sbf --manifest-path programs/descro_ext_resolvers/Cargo.toml
-
-# Build both (registry must be built first — descro depends on it)
+# Build (registry must be built first — descro depends on it)
 cargo build-sbf --manifest-path programs/descro_ext_resolvers/Cargo.toml && \
 cargo build-sbf --manifest-path programs/descro/Cargo.toml
-```
 
-### Test
-
-Tests use **LiteSVM** (in-process Solana runtime, no validator needed). They load the compiled `.so` from `target/deploy/` via `include_bytes!`, so the relevant program(s) must be built before running tests.
-
-```bash
-# Run all tests for a program
+# Test (programs must be built first — tests load .so via include_bytes!)
 cargo test --manifest-path programs/descro/Cargo.toml
 cargo test --manifest-path programs/descro_ext_resolvers/Cargo.toml
 
-# Run a single test by name
+# Single test / specific file
 cargo test --manifest-path programs/descro/Cargo.toml -- test_create_escrow
-cargo test --manifest-path programs/descro/Cargo.toml -- resolve_updates_stats_when_resolver_registered
-
-# Run tests in a specific file
 cargo test --manifest-path programs/descro/Cargo.toml --test test_resolve
+
+# Lint / Format
+cargo clippy --manifest-path programs/descro/Cargo.toml
+cargo fmt --manifest-path programs/descro/Cargo.toml
 ```
 
-### Lint / Format
+### TypeScript SDK (`sdk/`)
+
+No build step — consumed as raw TypeScript via `transpilePackages` in the app. Install from repo root:
 
 ```bash
-cargo clippy --manifest-path programs/descro/Cargo.toml
-cargo clippy --manifest-path programs/descro_ext_resolvers/Cargo.toml
-cargo fmt --manifest-path programs/descro/Cargo.toml
+yarn install
+```
+
+### App (`app/`)
+
+```bash
+# Dev server (Turbopack)
+yarn workspace descro-app run dev
+
+# Production build (generates tamagui.generated.css then runs next build)
+yarn workspace descro-app run build
+```
+
+## Repository Structure
+
+```
+programs/
+├── descro/                    — Escrow Program
+└── descro_ext_resolvers/      — Resolver Registry
+sdk/                           — @descro/sdk TypeScript client (workspace package)
+├── src/
+│   ├── idl/                   — Anchor-generated IDL JSON files
+│   ├── escrow.ts              — EscrowClient (instruction builders + fetchers)
+│   ├── registry.ts            — RegistryClient
+│   ├── listener.ts            — WebSocket subscriptions
+│   ├── pda.ts                 — PDA derivation helpers + program IDs
+│   ├── types.ts               — TypeScript types matching on-chain state
+│   └── index.ts               — Re-exports + DescroSdk convenience class
+app/                           — Next.js + Tamagui playground (workspace package)
+├── src/app/                   — Next.js App Router pages + providers
+├── src/components/            — UI components (EscrowDetail, ResolverPanel, …)
+└── src/hooks/                 — useEscrows, useEscrowDetail
 ```
 
 ## Architecture
 
+### Yarn Workspaces
+
+Root `package.json` declares `workspaces: ["sdk", "app"]`. The repo uses `nodeLinker: node-modules` (in `.yarnrc.yml`) because Next.js Turbopack does not support Yarn PnP. Run `yarn install` from the repo root.
+
+The app depends on the SDK via `"@descro/sdk": "workspace:*"` and lists it in `transpilePackages` in `next.config.ts` so Next.js compiles the TypeScript source directly (no SDK build step needed).
+
 ### Two-Program Protocol
 
-```
-programs/
-├── descro/                    — Escrow Program (Phase 1)
-└── descro_ext_resolvers/      — Resolver Registry (Phase 2)
-```
-
-`descro` depends on `descro_ext_resolvers` (with `features = ["cpi"]`). The registry does NOT depend on the escrow — this is intentional to avoid a circular dependency. Communication is one-way: escrow → registry via CPI.
+`descro` depends on `descro_ext_resolvers` (with `features = ["cpi"]`). Communication is one-way: escrow → registry via CPI. The registry does not depend on the escrow.
 
 ### Escrow Program (`descro`)
 
-**State:** A single `EscrowAccount` PDA holds all trade state. SOL is held separately in a `Vault` PDA (system-owned, data-free). The two-account split makes SOL transfers simpler: the vault is a pure lamport store.
+**State:** `EscrowAccount` PDA holds trade state. SOL is held in a separate `Vault` PDA (system-owned, data-free).
 
 **PDA seeds:**
-- Escrow: `["escrow", seller_pubkey, escrow_id_le_bytes]` — allows one seller to have multiple concurrent escrows
-- Vault: `["vault", escrow_account_pubkey]` — uniquely derived from the escrow account
+- Escrow: `["escrow", seller_pubkey, escrow_id_le_bytes]`
+- Vault: `["vault", escrow_account_pubkey]`
 
 **Instruction flow:**
 ```
@@ -68,39 +90,25 @@ create_escrow (seller) → deposit (buyer) → complete (buyer)
 cancel (seller, only from AwaitingDeposit)
 ```
 
-**SOL transfers** use raw `invoke` / `invoke_signed` (not Anchor's CPI helpers) because Anchor 1.0.x changed `CpiContext::new` to take `Pubkey` instead of `AccountInfo`, which conflicts with how system_program transfers work in practice.
+**SOL transfers** use raw `invoke` / `invoke_signed` (not Anchor's CPI helpers) because Anchor 1.0.x changed `CpiContext::new` to take `Pubkey` instead of `AccountInfo`.
 
 ### Resolver Registry (`descro_ext_resolvers`)
 
-**State:** `ResolverEntry` PDA at `["resolver", authority_pubkey]`. Tracks name, type, fee, and on-chain resolution stats.
+**State:** `ResolverEntry` PDA at `["resolver", authority_pubkey]`. Tracks name, type, fee, and resolution stats.
 
-**CPI authorization for `update_stats`:** Only the escrow program may call `update_stats`. This is enforced via a `["escrow_authority"]` PDA that only the escrow program can derive and sign for (`invoke_signed`). The registry verifies this signer has `seeds::program = ESCROW_PROGRAM_ID` (hardcoded constant in `lib.rs`).
+**CPI authorization:** Only the escrow program may call `update_stats`, enforced via an `["escrow_authority"]` PDA that only the escrow program can sign for. The registry verifies `seeds::program = ESCROW_PROGRAM_ID`.
 
-**`update_stats` is optional from the escrow side:** In `resolve()`, the handler checks `resolver_entry.data_is_empty()` before attempting the CPI. Resolvers that are not registered in the registry still work — stats are simply not tracked.
+**Optional CPI:** `resolve()` checks `resolver_entry.data_is_empty()` before calling the registry — unregistered resolvers still work.
 
-### Anchor 1.0.x Notes
+### Anchor / SDK Notes
 
-- `CpiContext::new(program: Pubkey, accounts: T)` — first arg is `Pubkey`, not `AccountInfo`
-- `AccountInfo<'info>` in `#[derive(Accounts)]` structs is deprecated; use `UncheckedAccount<'info>` with `/// CHECK:` doc comments
-- `#[derive(InitSpace)]` with `#[max_len(N)]` on `String` fields for automatic space calculation
-- The `cpi` Cargo feature (`no-entrypoint`) is required on the dependency when calling another Anchor program
-
-### Test Infrastructure
-
-Each program has a `tests/common/mod.rs` with shared helpers:
-- `setup()` — creates LiteSVM, loads `.so`, airdrops to test keypairs
-- PDA derivation helpers (`escrow_pda`, `vault_pda`, `resolver_entry_pda`, …)
-- `send()` / `try_send()` — wraps instruction in a `VersionedTransaction`
-- `ix_*` builders — construct typed `Instruction` structs via Anchor's `InstructionData` + `ToAccountMetas`
-- `read_*` helpers — deserialise on-chain accounts with `AccountDeserialize::try_deserialize`
-
-The `test_resolve_with_registry.rs` test loads **both** `.so` files into one LiteSVM instance to test the full CPI flow end-to-end.
+- **Anchor 1.0.x:** `CpiContext::new` takes `Pubkey` not `AccountInfo`; use `UncheckedAccount<'info>` with `/// CHECK:` instead of `AccountInfo<'info>` in account structs; `#[derive(InitSpace)]` + `#[max_len(N)]` for strings.
+- **`@coral-xyz/anchor@0.32.x`:** Use `new Program(idl, provider)` — the IDL's `address` field provides the program ID. The 3-argument form `new Program(idl, programId, provider)` is broken in 0.32.x.
+- **LiteSVM tests:** each `tests/common/mod.rs` has `setup()`, PDA helpers, `send()`/`try_send()`, `ix_*` builders, and `read_*` deserializers. `test_resolve_with_registry.rs` loads both `.so` files to test the full CPI flow.
 
 ### Program IDs
 
 | Program | ID |
 |---|---|
 | `descro` | `DjVR4EuYV6USMJFfsGZwhZ3y8rtWsmG8EvDY96GTqqi3` |
-| `descro_ext_resolvers` | `Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS` *(placeholder — update after first deployment)* |
-
-The `descro_ext_resolvers` ID is hardcoded as `ESCROW_PROGRAM_ID` inside the registry program. After deploying the registry for the first time, update `declare_id!` in `programs/descro_ext_resolvers/src/lib.rs` **and** `ESCROW_PROGRAM_ID` in `programs/descro_ext_resolvers/src/lib.rs` to match.
+| `descro_ext_resolvers` | `GwUPAKs3HHzCpj8uhet4NAnxk9GWNwfrYbpihu5DyFp` |