Request/Response Middleware

SIPS/sip-17.md

@@ -0,0 +1,121 @@
+---
+sip: (To be assigned)
+title: JSON RPC provider
+status: Draft
+author: Ronny Esterluss <[email protected]> (@esterlus)
+created: 2023-11-15
+---
+
+## Abstract
+
+Introduce a new endowment that would allow a snap to intercept outgoing traffic and act as a JSON RPC Provider according to [JSON-RPC 2.0 Specification](https://www.jsonrpc.org/specification).
+
+## Motivation
+
+We want to build a snap that gives users full privacy when doing JSON RPC calls using Metamask.
+This snap will leverage the power of [RPCh](https://rpch.net/).
+The original JSON RPC provider is still the target of the request, but the request will be routed through [HOPRNet](https://network.hoprnet.org/) to eliminate Metadata.
+
+
+## Specification
+
+> Formal specifications are written in Typescript.
+
+### Language
+
+The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
+"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
+"OPTIONAL" written in uppercase in this document are to be interpreted as described in [RFC 2119](https://www.ietf.org/rfc/rfc2119.txt)
+
+### Snaps permissions
+
+This SIP specifies a permission named `endowment:json-rpc-provider`.
+The permission signals to the platform that the snap wants to act as a JSON RPC Provider and intercept outgoing JSON RPC requests.
+
+This permission is specified as follows in `snap.manifest.json` files:
+
+```json
+{
+  "initialPermissions": {
+    "endowment:json-rpc-provider": {}
+  }
+}
+```
+
+### Snaps exports
+
+This SIP specifies a new exported event handler `onOutgoingJSONRpcRequest`.
+The event handler MUST be called whenever Metamask makes an outgoing JSON RPC request.
+
+#### Parameters
+
+An object containing:
+
+request - The JSON-RPC request
+provider - The target JSON RPC Provider
+
+* request
+
+This parameter MUST be present and MUST adhere to the official [JSON-RPC 2.0 Specification](https://www.jsonrpc.org/specification).
+
+* provider
+
+This parameter SHOULD be present. It contains the RPC URL of the intented RPC Provider (e.g. `https://mainnet.infura.io/v3/`).
+Metamask SHOULD use the configured RPC provider in the currently selected network.
+
+#### Returns
+
+A promise resolving to the response of the request or rejecting with an error.
+
+#### Example
+
+```typescript
+import { OnOutgoingJSONRpcRequestHandler } from '@metamask/snaps-types';
+import RPChSDK from '@rpch/sdk';
+
+const sdk = new RPChSDK("<ClientId>");
+
+export const onOutgoingJSONRpcRequest: OnOutgoingJSONRpcRequestHandler = async ({
+  request,
+  provider,
+}) => {
+    return sdk.send(request, { provider });
+};
+```
+
+#### Type definitions
+
+```typescript
+
+type OnOutgoingJSONRpcRequestHandler =
+  (args: { request: JSONRPCRequest, provider: string }) => Promise<JSONRPCResponse>;
+
+type JSONRPCRequest = {
+    readonly jsonrpc: '2.0';
+    id?: string | number | null;
+    method: string;
+    params?: any[] | object;
+};
+
+type JSONRPCResponse = JSONRPCResult | JSONRPCError;
+
+type JSONRPCResult = {
+    readonly jsonrpc: '2.0';
+    id?: string | number | null;
+    result: any;
+};
+
+type JSONRPCError = {
+    readonly jsonrpc: '2.0';
+    id?: string | number | null;
+    error: {
+        code: number;
+        message: string;
+        data?: any;
+    };
+};
+```
+
+## Copyright
+
+Copyright and related rights waived via [CC0](../LICENSE).