# Compliance program (https://docs.tsamara.xyz/docs/compliance-program)

The Anchor program Token-2022 calls on every transfer of the sukuk.

`tsamara-compliance` is deployed on devnet at
[`EjYxuJE4QE8P37scBxgWRHGigZ8hP6j3ysnSQ95MWXXG`](https://explorer.solana.com/address/EjYxuJE4QE8P37scBxgWRHGigZ8hP6j3ysnSQ95MWXXG?cluster=devnet).
The source is in `contracts/programs/tsamara-compliance`. It is unaudited.

## Instructions
| Instruction         | Who may call it               | What it does                                                                        |
| ------------------- | ----------------------------- | ----------------------------------------------------------------------------------- |
| `initialize_series` | The mint's freeze authority   | Writes the series config and the list of extra accounts the hook needs              |
| `register_investor` | The compliance authority      | Writes an investor record with a country code; refused if the country is restricted |
| `transfer_hook`     | Token-2022, during a transfer | Checks the recipient and the holding cap                                            |

## Accounts
| Account             | Seeds                       | Holds                                                                        |
| ------------------- | --------------------------- | ---------------------------------------------------------------------------- |
| `SeriesConfig`      | `config`, mint              | The compliance authority, the holding cap, up to 16 restricted jurisdictions |
| `InvestorRecord`    | `investor`, mint, wallet    | The wallet and its two-letter country code                                   |
| Extra account metas | `extra-account-metas`, mint | The accounts Token-2022 must pass to the hook                                |

## What the hook checks
1. It is running inside a token transfer. The source account's `transferring` flag must be set,
   so the hook cannot be called directly to fake a check.
2. The recipient has an investor record for this mint. The record is a derived address, so a
   record for another wallet or another series does not pass.
3. The recipient's country is not restricted.
4. The recipient's balance after the transfer does not exceed the holding cap.

## Errors
| Error                                                       | Meaning                                                                     |
| ----------------------------------------------------------- | --------------------------------------------------------------------------- |
| Signer is not the mint's freeze authority                   | Someone other than the compliance authority tried to initialize or register |
| Too many restricted jurisdictions                           | More than 16                                                                |
| The series is not offered to residents of this jurisdiction | Restricted country, at registration or on transfer                          |
| Transfer would exceed the per-investor holding cap          | The recipient would hold more than the cap                                  |
| The hook may only run during a token transfer               | The hook was called outside a transfer                                      |

## Known limits
* The hook does not run on mint, so the cap is not enforced by the program on a primary
  subscription ([issue 21](https://github.com/tsamara-xyz/tsamara/issues/21)).
* There is no instruction to change a series' rules after it is initialized.
* The compliance authority is the mint's permanent delegate. The program does not constrain how
  that key is used.

## Build
Install the Solana CLI and Anchor, then:

```sh
cd contracts
anchor build
bun run build     # also refreshes the binary the tests load
```