> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cloak.ag/llms.txt
> Use this file to discover all available pages before exploring further.

# Platform Components

> Responsibilities and boundaries of each Cloak subsystem

## SDK (`sdk/`)

* Primary integration interface for apps and wallets
* Exposes UTXO-first flows (`transact`, `partialWithdraw`, `swapWithChange`)
* Handles proof generation inputs, Merkle proof sourcing, retry semantics, and error mapping
* Includes chain-native scanner and compliance export helpers

## Programs (`programs/`)

* `shield-pool` is the runtime verifier/state-machine program
* Mint-scoped pools with PDAs such as `["pool", mint]`, `["treasury", mint]`, `["merkle_tree", mint]`
* Enforces proof validity, root membership, nullifier uniqueness, and transfer invariants
* Supports direct transact and two-phase swap state flow

## Packages (`packages/`)

* Circuit workspace for building Groth16 artifacts
* Canonical transaction circuit is 2-in/2-out with 9 public signals
* Tooling exports verifier keys for both SDK/clients and on-chain verifier use

## Recommended read order

1. [Platform Overview](/platform/overview)
2. [Transaction Flows](/platform/transaction-flows)
3. [Shield Pool Program](/protocol/shield-pool)
4. [Circuits Package](/packages/circuits)