Create session_keys_on_ten_gateway.md

design/ux/session_keys_on_ten_gateway.md

@@ -0,0 +1,57 @@
+# Session keys on Ten
+
+EIP-4337 (Account Abstraction) has popularised the concept of "Session keys" to minimize clicks.
+
+We want to offer a similar user-friendly experience to Ten dApp devs.
+
+To test the concept we will convert the Battleships game to a no-click UX.
+
+
+## The Ten Gateway as a Session Key manager
+
+The TG already manages VKs on behalf of users, so adding SKs is relatively straight forward.
+The advangate of the TG managing SKs is that it can return the funds to the EOA at any time.
+Anothe advantage is that they can be reused between sessions to avoid unecessary transactions.
+
+
+### The flow
+
+The logic of the game UI (javascript), will call and endpoint that will return a value transfer transaction that the user must sign in their MM, together with the address of the SK.
+
+The value transfer is required to prepay for the moves. 
+
+*Note: If the user authenticates with a service that is happy to prepay (a paymaster) then the signing step is not required.*
+
+The game will create unsigned move transactions, and will submit them to the gateway. 
+The TG will sign these transactions with the SK and submit them to the network.
+
+
+## Data ownership
+
+The SKs are a proxy for the EOA, so we want the EOA to read all data belonging to the SKs.
+The SKs are tx signers so the platform will treat them as EOAs.
+
+We need to introduce platform level support for SKs.
+
+### The main place will the `externally_owned_account` table:
+
+```
+create table if not exists obsdb.externally_owned_account
+(
+    id      INTEGER AUTO_INCREMENT,
+    address binary(20) NOT NULL,
+    owner   INTEGER, // this is a new field that will be populated for SKs and will point to the main account
+    primary key (id),
+    INDEX USING HASH (address)
+);
+```
+
+Todo : 
+ - Query for events:
+ - Query for receipts: 
+ - T
+
+### RPC endpoint on Node - Register session key
+
+- Receives a session key signed by a VK signed by the EOA.
+- Stores it to the `externally_owned_account` table and points to the true EOA