# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Commands

### Build

```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)
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
cargo test --manifest-path programs/descro/Cargo.toml
cargo test --manifest-path programs/descro_ext_resolvers/Cargo.toml

# Run a single test by name
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

```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
```

## Architecture

### 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.

### 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.

**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

**Instruction flow:**
```
create_escrow (seller) → deposit (buyer) → complete (buyer)
                                         → dispute (buyer|seller) → resolve (resolver)
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.

### Resolver Registry (`descro_ext_resolvers`)

**State:** `ResolverEntry` PDA at `["resolver", authority_pubkey]`. Tracks name, type, fee, and on-chain 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`).

**`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.

### Anchor 1.0.x 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.

### 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.