Base Is Migrating Off the OP Stack. Here's What I Checked Before Building.

In February 2026, Coinbase announced what amounted to a quiet bombshell: Base is moving away from the OP Stack toward an in-house "unified codebase." I caught the news right as I was prepping a contract deployment. My entire stack — chain IDs, RPC endpoints, Foundry configs, wagmi imports — had been built for the OP Stack. My first thought wasn't "this is a crisis," but it was: is my documentation about to become obsolete at the exact moment I hit deploy? I went down the rabbit hole. Here's what's actually changing. What the migration actually is (and isn't) The new system is the unified stack, currently living in github.com/base/base. Don't let the "in-house codebase" framing spook you. This isn't a VM overhaul or a sudden pivot to ZK (yet). It's an infrastructure consolidation — pulling components previously scattered across different repositories into a single Base-managed binary, built on open-sourced components including Reth, the Rust Ethereum execution client. Status as of now: