Experience Base58's

Mempools In-Depth

Navigating the mempool is one of the trickiest problems in modern layer-2 development. In this 1-day masterclass, we’ll dig deep into the various problems and techniques for over-coming them.

Mempools In-Depth

Expect to walk away with a better understanding of mempoolfullrbf, hands-on experience with both RBF and CPFP, and a good outline of the upcoming changes to mempool policies, such as package relay and v3 transactions.

Class size is limited to 20.


The day will start with us doing a quick version of the World Famous Bitcoin LARP, to make sure everyone has a good understanding of how the mempool and transaction gossiping works.

We’ll then do some lectures around various mempool fee-bumping techniques, and see if we can figure out how to execute the bumps for ourselves in the LARP and in real life on testnet (using Replit or local copies of bitcoin-core, if you have them.)

For the afternoon, we’ll move on to pinning attacks, anchors, and the current and prospective proposals for how to mitigate mempool risks while preserving miner paydays.

Topics we’ll cover

  • BIP125
  • transaction pinning
  • CPFP
  • RBF
  • mempoolfullrbf
  • package relay
  • anchors + ephemeral anchors
  • on-chain costs and trade-offs of these approaches
  • v3 transactions + transaction sponsors

About the Instructor

Nifty’s a long time mempool contemplatoor, her thoughts on mempools are probably best known via her classic bitcoin-dev mailing list post “the mempool is dead, long live the mempool”.

What to know before class (pre-requisites)

The ideal participant for this class is someone who works as a dev on projects that either deal with layer-2s like Lightning or work on applications that are subject mempool policy constraints.