The first blockchain indexer to prove correctness and completeness. Verifiable on-chain.

Joined February 2025
Ethereum is moving toward a world where computation happens elsewhere and only proofs reach the chain. The same should be true for data. Smart contracts shouldn't need to trust external indexers or oracles. They should be able to verify the data they consume.
Ultimately, precompiles and EVM are both the wrong place to put most cryptography support into Ethereum. The reason is that precompiles and EVM both operate on data that has to be included into the ethereum chain somehow, which realistically means included in a block as calldata. That space is limited - even with PeerDAS and blocks-in-blobs, there's a practical cap of ~8 MB/s before it starts getting uncomfortable. Remember: it's not a blockchain. It's a cryptographic world computer. Any data/computation that does not need to be in the "main thread" of data/execution should not be put into the main thread. Instead, the correct solution is... EIP-8288 maximalism. If you have any heavy computation that's self-contained, compute it and STARK it client-side (this is quickly getting faster and faster, even on phones), and push the STARK through the EIP-8288 recursive aggregation mechanism. The chain sees the fact that the computation was done and what the result is; it never needs to see the actual data and computation. This way everyone can use whatever cryptography they want, the Ethereum chain can be lean, and we never need to add more precompiles again.
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Willow now supports @StellarOrg, our first non-EVM chain. A contract on Ethereum mainnet verified our proof of 64 Stellar ledgers, with 20,361 Soroban events and balance changes. Ethereum contracts can now act on Stellar data trustlessly 🤝
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The GENIUS Act takes effect no later than January 18, 2027. Among other things, it requires the CEO and CFO of every permitted US stablecoin issuer to certify their tokens outstanding each month. With a Willow proof, they can sign knowing it's correct 👇
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Introducing eth-historian, our open-source library for verifying historical Ethereum data. Until now, there were basically two options if you wanted to read old Ethereum (pre-Capella) data off-chain: → trust an RPC/indexer → run a multi-TB archive node eth-historian introduces a third, easy, trustless option. It allows anyone to pull a block, all the way back to genesis, from any source, even one they don't trust, and then verify it's real against Ethereum's own records. Then, you can verify that any specific tx, receipt or log is in that block. This is what enables Willow's historical indexing to prove the event lists it delivers. Rust, TS, Python, Go. MIT/Apache. PR/Issues welcome. github.com/willow-network/et…
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Replying to @_Eazyboy_
With The Graph or Dune, you trust that the data was indexed correctly. With Willow, you get a proof that shows: - Every event is really on-chain - No events were missed - Every value computed from the events is correct And your smart contract can verify the proof itself 🤝
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That’s a nice Willow tree
London, you are beautiful.
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Major upgrade! Willow now supports Arbitrum One, Robinhood Chain, OP Mainnet, Unichain, and Ink, in addition to Ethereum and Base. Contracts on each chain can now act on data from all others trustlessly 🤝 @arbitrum @RobinhoodCrypto @Optimism @unichain @inkonchain
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Almost every crypto application you use runs on a blockchain indexer. An indexer reads every block and turns the raw on-chain data into something actually useful. Billions of dollars move on that data every day, and almost all of it is taken on trust 👇
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That's why we built Willow, the first cryptographically verifiable blockchain indexer. We index blocks and prove that the data is correct, and most importantly, complete. No missing events. You don't trust the indexer, you verify it, right in your app.
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Our proofs are verified on Ethereum, so smart contracts can now act on indexed data trustlessly too. Come build with us willow.tech
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ZK is becoming the foundation and Willow proves the indexing layer.
Vitalik: Ethereum is Becoming More Than a Blockchain Speaking at the 2026 Shanghai Blockchain International Week, Ethereum co-founder Vitalik Buterin shared a broader vision for where Ethereum is heading. His main point: Ethereum is evolving from a blockchain that executes everything into a global system focused on computation, privacy and verification. Here are the key ideas: 1/ ZK is becoming the foundation → Instead of every node doing the same computation, users or other systems can do the work and generate a proof. Ethereum only needs to verify that proof. 2/ Privacy becomes programmable → Vitalik said blockchain is moving beyond simply answering “Who can send what?” The next question is “Who can see what?” This means applications could control which information is visible without exposing everything publicly. 3/ Scaling through proofs → Complex computations can be split, processed in parallel and compressed into proofs before being verified on Ethereum. This could allow much more computation without putting all of it directly on-chain. 4/ Ethereum becomes a full pipeline → Vitalik described a future involving user devices, private transaction pools, multiple participants, block construction, L2s and finally Ethereum for verification. Ethereum does not need to perform every step itself. 5/ AI changes development → AI can help developers write, test and formally verify increasingly complex cryptographic systems. Vitalik believes this can make advanced Ethereum infrastructure both faster to build and more secure. 6/ Quantum resistance matters → Ethereum is also moving toward quantum-safe cryptography, with STARK-based systems playing an important role in the longer-term roadmap. Ethereum's future may not simply be about making the L1 faster. It is about building a trust layer where computation can happen anywhere, privacy can be programmed, and complex results can be mathematically proven and verified on-chain.
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Willow brings data from all supported chains together in one place, with cryptographic proof that it's indexed correctly. Verifiable anywhere. Check out the block explorer here 👇 explorer.willow.tech/?s=2
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Replying to @zsfelfoldi
@zsfelfoldi gets it. EIP-8304 (Trustless Log Index) is massively undervalued. Verifiable data access is a huge weak spot for crypto, and as financial institutions come onchain, it'll become glaring. @willow_protocol is happy to build a verifier for it. ethresear.ch/t/scaling-ether…
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Willow is the first cryptographically verifiable blockchain indexer.
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Since KelpDAO's $292M bridge hack in April, six more bridges have been hacked in roughly the same way. No keys were stolen. Each bridge paid out on an event that never actually happened on the other chain. They lost about $31M altogether, and all six were Willow-preventable.👇
In April, KelpDAO's bridge was hacked for $292M. The attacker didn't steal a key or break a contract. They fed a verifier a fake view of Unichain, and it confirmed a tx that never actually happened. Still, that's how most bridges, oracles, and indexers read the chain today 👇
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- Across, under $4M: its relayer took Solana deposit logs from failed transactions as real. - Coreum, 200,000 XRP: 17 of 28 relayers signed against transfers that never reached the bridge. - Allbridge, $190K: a Circle-signed message claiming a Polygon burn that never happened.
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All of these had signatures or relayers in front of them and still paid out on something that wasn't there. Willow proves its data against the underlying chain's commitment, so it only passes if the deposit is real. Moving money on indexed chain data?👇 willow.tech
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