0xMowgli — Writing https://0xmowgli.com/blog Field notes by Oussama Allamou on Solana execution, trading infrastructure and smart contracts. en How a Solana transaction actually lands: leaders, shreds, gRPC and Jito https://0xmowgli.com/blog/how-solana-transactions-land https://0xmowgli.com/blog/how-solana-transactions-land Wed, 07 Oct 2026 00:00:00 GMT A practitioner walkthrough of the path a Solana transaction takes from your bot to finality: RPC forwarding, the leader TPU, shreds over Turbine, Geyser gRPC, Jito bundles, and what really improves landing rate. SolanaTrading BotsgRPCJitoInfrastructure Why you should never store private keys in .env files https://0xmowgli.com/blog/never-use-env https://0xmowgli.com/blog/never-use-env Thu, 14 Nov 2024 00:00:00 GMT A .env file keeps your private key in plain text where git, dependencies and backups can reach it. How to move it into Foundry's password-encrypted keystore with cast wallet import, with a steppable diagram of what changes. FoundrySecurityPrivate KeysKeystore assert vs require in Solidity: which one to use, and what each failure means https://0xmowgli.com/blog/assert-vs-require https://0xmowgli.com/blog/assert-vs-require Sat, 02 Nov 2024 00:00:00 GMT require validates what callers send. assert states what your own code guarantees. A steppable diagram of one call passing through both, the error each one produces, and how gas behaves since Solidity 0.8.0. SolidityError HandlingSmart Contracts ERC-20 approval frontrunning: how a changed allowance gets spent twice https://0xmowgli.com/blog/front-running https://0xmowgli.com/blog/front-running Fri, 01 Nov 2024 00:00:00 GMT When you change an ERC-20 allowance with approve, a spender watching the mempool can spend the old allowance first and the new one after. A steppable walkthrough of the race, why approve allows it, and the fixes that close it. SolidityERC-20SecurityFrontrunning Slippage parameters in Solidity: what amountOutMin really protects https://0xmowgli.com/blog/Slippage-parametres https://0xmowgli.com/blog/Slippage-parametres Tue, 29 Oct 2024 00:00:00 GMT Slippage is the gap between the price you were quoted and the price your swap executes at. How amountOutMin and deadline turn a tolerance into an on-chain check, with a steppable diagram and the mistakes that leave a swap unprotected. SolidityDeFiSlippageDEX receive vs fallback in Solidity: which one runs, and when https://0xmowgli.com/blog/receive-fallback https://0xmowgli.com/blog/receive-fallback Mon, 28 Oct 2024 00:00:00 GMT receive runs when a contract gets ether with empty calldata. fallback runs when the calldata matches no function, or when ether arrives and there is no receive. A steppable decision tree, the gas stipend, and the cases where neither runs. SolidityEther TransfersSmart Contracts