Peter Todd joins MARA as lead maintainer of Slipstream private mempool

On October 1, 2026, MARA Foundation announced that longtime Bitcoin Core contributor Peter Todd joined as lead maintainer of Slipstream, its private mempool service. Slipstream allows direct transaction submission to MARA Pool, bypassing Bitcoin's public network. The service proved critical following a July 2026 Coldcard wallet vulnerability that led to $115 million in thefts, helping secure over 9,000 BTC. Todd aims to use Slipstream as a proving ground for experimental protocols like quantum-safe transactions.

Peter Todd joins MARA

• ▪Peter Todd, who co-authored BIP 125 for opt-in replace-by-fee and created OpenTimestamps, launched Libre Relay in 2024 as a Bitcoin Core fork with relaxed transaction relay rules
• ▪On October 1, 2026, MARA Foundation announced that longtime Bitcoin Core contributor Peter Todd joined the organization as the lead maintainer of Slipstream, a private mempool service
• ▪Peter Todd stated that his role at Slipstream complements his work on Libre Relay and provides an opportunity to build bridges between Bitcoin Core developers and miners

How Slipstream bypasses public relay rules

• ▪MARA introduced the Slipstream service in February 2024, allowing users to submit transactions directly to MARA Pool without routing them through Bitcoin's public peer-to-peer network
• ▪Private mempools like Slipstream provide miners with an alternative channel to process transactions that are otherwise restricted or prohibited by public Bitcoin relay rules
• ▪Bitcoin's relay policy consists of locally configurable rules that nodes impose on unconfirmed transactions before accepting them into mempools, which do not apply once a transaction is in a block

Slipstream's role in Coldcard recovery

• ▪In July 2026, Coldcard warned that its hardware wallet firmware from 2021 to July 2026 could generate poor entropy, which hackers exploited to steal over $115 million in user funds
• ▪MARA Foundation reported that Slipstream facilitated the secure transfer of over 9,000 BTC from vulnerable Coldcard multisignature wallets by keeping recovery transactions private until they were mined

Debatable claims

• ▪Bitcoin's public relay rules go too far in restricting non-standard transactions
• ▪It is appropriate for Bitcoin Core contributors to work for private mining enterprises
• ▪Private mempools like Slipstream do more harm than good to Bitcoin
• ▪Bitcoin mempool policy should be driven by market demand rather than developer-set rules