diff --git a/solidity/contracts/hooks/README.md b/solidity/contracts/hooks/README.md new file mode 100644 index 000000000..6c538dfd4 --- /dev/null +++ b/solidity/contracts/hooks/README.md @@ -0,0 +1,58 @@ +# Post-Dispatch Hooks + +Post-dispatch hooks allow developers to configure additional origin chain behavior with message content dispatched via the Mailbox. + +```mermaid +flowchart TB + subgraph Origin + Sender + M_O[(Mailbox)] + Hook[IPostDispatchHook] + + Sender -- "dispatch(..., metadata, hook)\n{value}" --> M_O + M_O -- "postDispatch(message, metadata)\n{value}" --> Hook + end +``` + +If the `postDispatch` function receives insufficient payment, it may revert. + +> [!WARNING] +> Post-Dispatch Hooks may be replayable. Developers creating custom hooks should implement safe checks to prevent this behavior. [Here](./warp-route/RateLimitedHook.sol#L16) is an example implementation. + +### Quote Dispatch (Fees) + +Fees are often charged in `postDispatch` to cover costs such as destination chain transaction submission and security provisioning. To receive a quote for a corresponding `postDispatch` call, you can query the `quoteDispatch` function. + +The Mailbox has a `quoteDispatch` function that returns the aggregate fee required for a `dispatch` call to be successful. + +```mermaid +flowchart TB + subgraph Origin + Sender + M_O[(Mailbox)] + R_H[RequiredHook] + Hook[Hook] + + Sender -- "quoteDispatch(..., metadata, hook)" --> M_O + M_O -- "required = quoteDispatch(message, metadata)" --> R_H + M_O -- "fee = hook.quoteDispatch(message, metadata)" --> Hook + M_O -- "required + fee" --> Sender + end +``` + +The custom `metadata` will be passed to the required hook's `quoteDispatch` and `postDispatch` functions, before being passed to the default hook's `postDispatch` function. + +```mermaid +flowchart LR + subgraph Origin Chain + Sender + M_O[(Mailbox)] + R_H[RequiredHook] + D_H[DefaultHook] + Sender -- "dispatch(..., metadata){value}" --> M_O + + M_O -. "fee = quoteDispatch(...)" .- R_H + M_O -- "postDispatch(metadata, ...)\n{fee}" --> R_H + M_O -. "postDispatch(metadata, ...)\n{value - fee}" ..-> D_H + end +``` diff --git a/solidity/contracts/isms/README.md b/solidity/contracts/isms/README.md new file mode 100644 index 000000000..d9f74f397 --- /dev/null +++ b/solidity/contracts/isms/README.md @@ -0,0 +1,20 @@ +# Interchain Security Modules + +Interchain security modules allow developers to configure additional security checks for message content dispatched via the Mailbox. + +```mermaid +flowchart LR + subgraph Destination Chain + ISM[InterchainSecurityModule] + Recipient[Recipient] + M_D[(Mailbox)] + + M_D -- "verify(metadata, message)" --> ISM + ISM -. "interchainSecurityModule()" .- Recipient + M_D -- "handle(origin, sender, body)" --> Recipient + + end +``` + +> [!WARNING] +> Interchain security modules may be replayable. Developers creating custom modules should include replay protection if necessary. [Here](./warp-route/RateLimitedIsm.sol#L23) is an example implementation.