Eureka Labs Raises $6.7M to Build 'Programmable Blocks' for Ethereum

Tel Aviv Startup Reimagines Ethereum Block Construction

Eureka Labs, an infrastructure startup based in Tel Aviv, has closed a $6.7 million seed round to advance its vision of "programmable blocks" on Ethereum. The concept reimagines blocks from passive containers that merely package and order transactions into active execution environments capable of running logic on the fly.

According to The Block, the approach represents a fundamental shift in how Ethereum blocks function. Project lead Nir Magenheim explained that the architecture enables embedding logic directly into the block construction process, unlocking capabilities that go beyond what smart contracts alone can offer.

Why It Matters

Programmable blocks extend Ethereum's capabilities to a layer that was previously untouched by developers. While smart contracts operate within their own execution environment, this new approach provides guarantees at the block level itself. This enables applications that temporarily need significant capital, strict operation sequencing, or complex computations unsuitable for direct on-chain execution.

Magenheim stated that these new capabilities will facilitate more sophisticated trading strategies, efficient DeFi protocols, and entirely new categories of decentralized applications.

Core Technical Features

The Eureka Labs architecture introduces four key capabilities:

• Intra-block credit — users can access uncollateralized loans within a single block, provided they are repaid before finalization;
• State-aware pre-computation — complex calculations are performed during block assembly using the precise network state, reducing fees and improving system stability;
• Execution-time external data access — off-chain data is integrated in real time during the execution process;
• Deterministic transaction placement — guaranteed execution of transactions in a strictly defined order.

Business Model and Market Position

Eureka Labs builds on Ethereum's PBS (Proposer-Builder Separation) architecture, where specialized builders — rather than validators — are responsible for constructing blocks. Magenheim believes these operators will eventually evolve into a new execution layer for the blockchain, much like smart contracts once expanded the network's base functionality.

The startup generates revenue through fees on transactions included in its constructed blocks. The team comprises 12 people, with headquarters in Tel Aviv and a recently established research center in Poland. Both offices are actively hiring.

Ethereum block producer rankings. Source: Rated Network

According to Rated Network data, Eureka began operations in December 2024 and has already become the fourth-largest Ethereum builder by number of blocks produced. However, the company's market share sits at a modest 1.5%, while nearly 96% of the segment is controlled by three dominant players: Titan Builder, BuilderNet, and Quasar Builder.

Funding Details

The seed round was co-led by venture firms Spark Capital and Collider Ventures. Other participants included Varrock Ventures, Node Capital, Reverie, Very Early Ventures, Atka, Synergis, Masterkey, and several angel investors, including CoinList president Scott Keto.

As part of the deal, Collider Ventures founding partner Avishai Ovadia joined Eureka's board of directors. According to co-founder and CEO Nir Magenheim, the capital was raised in two tranches: $4.7 million in April 2025 and the remaining $2 million from Spark Capital in June. The deal was structured as a SAFE with token warrants.