Flashbots is hosting a CTF (Capture the Flag) event this weekend. The CTF is open to all and is intended to support a range of skillsets — from novice, to expert, to Scott Bigelow. Welcome aboard
Location: Goerli testnet.
Registration: Optional. To receive updates or sponsored Goerli ETH, visit the CTF homepage.
How to compete
Format: There are 10 flags. Each flag is activated by specific transaction(s) or bundle(s). To capture a flag, searchers must land a bundle containing the hash of the activating transaction or bundle, followed by their own backrun. Their backrun transaction must invoke a valid CTF contract method with the correct inputs to capture its flag.
Note: Activations are submitted privately to MEV-Share. They cannot be found in the public mempool and can only be sent by the CTF owner.
Points: Searchers will be awarded between 1-4 points for each flag captured. Points increase with difficulty. Each searcher can only earn points once per flag, but each flag can be captured by multiple searchers.
- Listen for hints about activation transactions and bundles emitted by the Goerli MEV-Share SSE endpoint: https://mev-share-goerli.flashbots.net/
- Submit bundles to capture activated flags at the Goerli Bundle Relay: https://relay-goerli.flashbots.net/
- Learn to use MEV-Share: Getting Started | Flashbots Docs and More Resources | Flashbots Docs
- Discuss and ask questions: Discord
Notes about Goerli
It may take multiple blocks to successfully land a CTF bundle on Goerli. Not every block in Goerli is built by Flashbots, and bundles submitted for other blocks will not succeed even if your solution is correct. Bundles should be submitted repeatedly, for sequential blocks, until they land on-chain.
The quest begins…
Thanks to everyone who participated in the CTF!
Over 300 searchers registered and 61 managed to capture one, or more flags. All addresses that captured a flag will receive a commemorative chest of gold. To celebrate a couple of searchers that surprised and impressed us we’ve also created a set of special badges.
The NFTs are all non-transferrable, burnable, and awarded on Goerli + mainnet.
- The Victory badge: The fastest searcher to complete the entire challenge (in under 5 hours!)
- The Pirate badge: For the runners up who completed the CTF in record time and captured all 10 flags.
- 0x3e5e -@vinami
- The Scribe badge: For the best write up of the CTF
- The FOSS badge: For sharing an excellent open source solution to the CTF and advancing open source client libraries for MEV-Share
- The Spy badge: To the searcher who discovered our form link before we even announced the CTF and was the first to register.
Check out the leaderboard and Dune dashboard for a deeper dive into the results!
You can use your CTF bots to keep searching on MEV-Share. Just swap the endpoints to http://mev-share.flashbots.net / http://relay.flashbots.net to start backrunning real transactions on mainnet.
If you’re new to MEV, take a look at the example bots and guides for how to update your strategy.
Have feedback or ideas for Flashbots? We’d love to hear them — drop us a comment or share your thoughts in this form.
Congrats and thanks for playing!