Actively fighting a compromised Telegram right now, please don't trust any messages from me without security question first. I have access but I can't remove attacker from my active sessions.

Contender is a tool for sending lots of Ethereum transactions — but did you know you can plug in custom logic too? We used it to build a cross-chain tester that sends messages between two chains. Here’s how it works: Normally, when you send a tx with Contender, that’s it. But we wrote a custom callback — a bit of code that runs after each tx is sent — to check if the tx triggered a cross-chain message. If it did, our callback sends a second tx to another chain to relay the message. This mimics how OP-Interop works under the hood, but without relying on an auto-relayer. To do this, our callback: - waits for the first tx to land - looks for a special log in the receipt - sends a follow-up tx with the message to the second chain Contender makes this possible by letting you run async Rust code in the background after each tx. This is what it looks like (rust pseudocode): The OP-Interop spammer lives here: 🔗 But this is just one use case. Callbacks let you do whatever you want after a tx (or batch of txs) is sent — your imagination is the limit! For a deeper dive on the code behind this project, check out my forum post: And be sure to check out the contender repo -- we're adding more features all the time!

BuilderNet v1.5 → This release has a 2x faster median fill time, 5x faster root hash, and adds trusted TLS certificates for more secure orderflow submission. TDX images can be reproducibly built using the guide below.

v1 of our @ARIA_research opportunity space 'Trust Everything, Everywhere' is now live! we're focusing on new security primitives that straddle digital and physical worlds, and will be spending the next months zeroing in on a £10-100m first challenge within the space 🎯

🚨 Going live tomorrow at 1PM EST on X! 🚨 I’ll be coding up a demo using Unichain Bundles to explain how they differ from normal bundles, and what you can do with them. Come hang out, ask questions, and learn something new! 🔗

Bro, can you pass me that leaflet? Brochure.

Favourite day of the year

0/ Say hello to @ethereumhouseSF A local hub for Ethereum builders, researchers, founders and investors in San Francisco’s @frontiertower. We’re excited to be supporting the Ethereum House with grant funding and collaboration from EF team members.

I wrote a post to introduce my personal favorite attack idea from the first half of 2025: the MEV-phishing attack — an attack targeting the smartest bots in the MEV ecosystem.

Exercise left to the reader