buildernet.org

What It Is

BuilderNet is a decentralized block-building network for Ethereum. It is not positioned as an exchange, wallet, or conventional DeFi app, but rather as MEV and block-building infrastructure. Its goal is to let multiple builder nodes share order flow, coordinate bids, and return the MEV value generated by contributed order flow to users while preserving transaction privacy. According to the documentation, BuilderNet was publicly launched in November 2024, with early nodes operated by Flashbots, Beaverbuild, Nethermind, and others.

Core Capabilities and Security

The platform supports sending atomic transaction bundles via eth_sendBundle, as well as sending individual signed transactions via eth_sendRawTransaction. More advanced use cases also include Priority updates, but this feature requires an API key and is described in the documentation as experimental. Security is a major focus for BuilderNet: builder nodes run inside Trusted Execution Environments (TEE), combined with order-flow encryption, remote attestation, attested TLS (aTLS), and verifiable system integrity. This allows order-flow providers to verify the software and environment running on a node. Its TLS private key is described as remaining inside the TEE instance, which is especially important for private transaction channels.

Pricing and Refund Mechanism

The main documentation does not disclose subscription fees, fixed service charges, or a commercial pricing table. The most cost-relevant mechanism is MEV refunds: eth_sendBundle can set refundPercent, ranging from 1 to 99, to specify the desired percentage of priority fees and coinbase payments to be refunded. The refund deducts the cost of the refund transaction itself. Note that eth_sendRawTransaction is explicitly not eligible for refunds. Refunds can be queried through several buildernet_getFeeRefunds-related APIs, and delayed refunds as well as custom refund recipient addresses are also supported.

Pros, Cons, and Who It Is For

Its strengths include strong privacy protection, relatively transparent mechanisms, complete API documentation, and an open-source, verifiable runtime-environment design. It also provides global, US, Europe, and Asia-Pacific endpoints, making low-latency access easier. The drawbacks are that it is still in an early stage, and the documentation clearly states that the system will evolve quickly. Direct integration requires technical capabilities such as signed requests, certificate validation, and TEE attestation, making it unfriendly for ordinary users. It is better suited to searchers, wallets, bots, order-flow providers, AMMs, or protocol operators. Regular users can access it indirectly through Flashbots Protect.

China Access and Alternatives

The main documentation does not provide information on network reachability from mainland China, payment methods, or localization support, so its China access status can only be marked as unknown. Since BuilderNet does not involve fiat deposits, trading pairs, or leveraged derivatives, it also has no traditional payment channels. Alternatives to consider include Flashbots Protect, Flashbots Bundle Relay, and other MEV-Boost private transaction or block-building infrastructure.