Merge pull request #455 from Chia-Network/update-rbf-specifics

Update rbf specifics

docs/architecture/mempool.md

@@ -77,6 +77,14 @@ A transaction can replace another transaction in the mempool if it spends at lea
 
 For example, if the original transaction spent coins A and B, then another transaction that spends A, B, and C can replace it. However, a transaction that spends B and C cannot. This prevents denial-of-service (DOS) attacks, as well as censorship of transactions. There is also a minimum fee bump which might depend on mempool software being used. In `chia-blockchain`, this is set to 5 fee-per-cost. This prevents spam replacement transactions.
 
+The full conditions for replace by fee are:
+1. The new spend bundle needs to include at least all the spends in the original one (can include additional spends)
+2. The new spend bundle needs to pay a higher fee per cost than the original one (and higher than the [minimum fee required for inclusion](https://docs.chia.net/mempool/#fee-required-for-inclusion))
+3. The new spend bundle needs to pay at least 10000000 mojos more in fees than the original one
+4. If there were any time-locks associated with the original spend, the new spend bundle has to have the same time-lock
+
+The replace by fee logic can be found [here](https://github.com/Chia-Network/chia-blockchain/blob/main/chia/full_node/mempool_manager.py#L678)in the codebase)
+
 ## Block Creation
 
 When the farmer makes a block, they will select the highest fee-per-cost transactions from the mempool until they reach the maximum block size. These spend bundles are combined into one large spend bundle, which is guaranteed to be valid,