Opening
Are you wondering how upcoming Ethereum upgrades will affect the way blocks are built, the cost of transactions, and the security of the network? This article explains the key concepts behind the Glamsterdam upgrade and what they mean for anyone earning or interacting with Ethereum.
The plain explanation
Ethereum’s protocol evolves through scheduled upgrades, often called “forks.” A fork can add new rules, change existing ones, or improve performance. The Glamsterdam upgrade introduces three major changes:
- Proposer‑Builder Separation (PBS): Currently, a validator (the “proposer”) can also act as a block builder, assembling transactions into a block and then proposing it. PBS splits this role. Specialized block builders create the most profitable block, then hand it to validators who simply propose it. This reduces the incentive for validators to collude with builders and limits the influence of external “MEV” (Maximum Extractable Value) extraction tools.
- Block‑level access lists: An access list records which accounts and storage slots a transaction will read or write. By storing this information at the block level, the network can more efficiently verify that a block’s state changes match the declared accesses, improving security and potentially lowering verification costs.
- New gas pricing model: Gas is the fee paid for computational work and data storage on Ethereum. The new model aims to price data creation and access more accurately, meaning contracts that use fixed gas amounts or hard‑coded limits may need to be updated to avoid running out of gas.
In simple terms, PBS makes block production more transparent, access lists give the network a clearer picture of what each block does, and the gas pricing tweak aligns fees with actual resource use.
A real example
On September 29, 2026, Ethereum developers announced that the Glamsterdam upgrade will first activate on the Sepolia testnet on October 6, 2026. Sepolia node operators are required to update both their execution‑layer client (which runs smart contracts) and consensus‑layer client (which handles block validation) before the upgrade goes live. The same changes are planned for the mainnet, although a specific mainnet date has not yet been set.
What it means for you
If you earn Ethereum by running a validator, PBS changes how you receive block rewards. Instead of building blocks yourself, you will receive blocks from professional builders and simply attest to them. This can simplify validator operations but also means you rely on the builder market for block quality.
For developers and users, the new gas pricing may affect transaction costs. Contracts that assume a constant gas amount could fail if the new model charges more for data access. Updating contract code to use dynamic gas estimations can help avoid failed transactions.
Block‑level access lists improve security by making it easier to detect malformed blocks. This reduces the risk of attacks that try to exploit inconsistencies in state changes, which benefits anyone holding or transacting with Ether.
What to check / how to judge
- Ensure your validator software supports PBS. Most major clients have released versions compatible with the upgrade; verify you are running the latest release.
- If you use smart contracts, audit them for hard‑coded gas limits. Replace fixed values with gasleft() checks or use libraries that estimate gas dynamically.
- Monitor builder market fees if you are a validator. Higher builder fees can reduce your net reward, so compare multiple builders before committing.
- Test your contracts on Sepolia after the October 6 activation. The testnet mirrors mainnet changes, giving you a safe environment to spot any issues before the upgrade reaches mainnet.
FAQ
What is “MEV” and why does PBS matter?
MEV stands for Maximum Extractable Value, the profit a block builder can earn by reordering, including, or censoring transactions. PBS separates block building from proposing, limiting a validator’s ability to capture MEV directly and making the process more transparent.
Do I need to change my wallet or exchange accounts?
No. Wallets and exchanges interact with the network at the protocol level, and the upgrade is handled by the underlying clients. However, if you use custom gas settings, you may need to adjust them to match the new pricing model.
Will the upgrade increase transaction fees?
The new gas pricing aims to reflect actual resource usage more accurately. For simple transfers, fees may stay similar, but contracts that store large amounts of data or perform many reads/writes could see higher fees.
Is PBS optional for validators?
No. Once the upgrade is live on mainnet, all validators must follow the protocol rules, which include using PBS. Early adoption on testnets is encouraged to ensure a smooth transition.
This article references reporting from cointelegraph.com.
