Announcing mamo-1: Celestia’s 128MB block testnet
Today we're introducing mamo-1, a public testnet that pushes Celestia to new extremes. Built for applications at the frontier, mamo-1 delivers 128MB blocks and 21.33MB/s of permissionless throughput—offering the infrastructure needed to test real-world, high-throughput applications and prepare for the road to 1GB blocks.
That’s over 16x the throughput of Celestia mainnet today, which currently supports 8MB blocks.
Meet mamo-1 🦣
mamo-1 is now live. It’s a high-performance testnet specifically designed to:
- Simulate real-world validator configurations,
- Stress-test the network under extreme data load,
- Validate scalability features and optimizations that pave the way for future mainnet upgrades.
With 128MB blocks produced every 6 seconds, mamo-1 enables data throughput of 21.33MB/s—a seismic leap from Celestia’s earlier testnets and a major milestone in the modular blockchain scalability roadmap.
👉 Track live activity on the block explorer
👉 Start testing on mamo-1 with our how-to guide
Why mamo-1?
The launch of mamo-1 follows the successful Mammoth Mini prototype devnet, which showcased 27MB/s under experimental conditions. Now, mamo-1 provides a similar level of throughput but in a more production-ready network available to everyone. It simulates the real-world operational complexity of a distributed validator network, including 21 validators spread across Amsterdam, Paris, and Warsaw.
This setup enables apps to push their stack to the limit, simulate production environments, and benchmark performance against the most demanding workloads. Unlike the Mammoth Mini devnet, which focused on consensus-layer performance, mamo-1 also integrates with Celestia’s data availability network—supporting light node sampling and real-world DASing, and making it a far more complete and realistic test environment.
What makes it possible: Vacuum! and more
The mamo-1 testnet showcases the culmination of multiple protocol innovations that bring us closer to scalable, high-throughput modular infrastructure.
One of the most critical breakthroughs powering mamo-1 is Vacuum! — a high-efficiency data propagation protocol designed to move data through the network as fast and reliably as possible.
Introducing Vacuum!
Vacuum! leverages a form of lazy gossiping, where peers only send data to those who explicitly ask for it, massively cutting down on redundant traffic. It introduces Validator Availability Certificates (VACs) to enable validators to declare which data blobs they’re holding and prioritize what data gets propagated based on relevance, validator, and transaction priority.
Rather than pre-determining propagation paths (like Turbine), Vacuum! discovers optimal routes in real-time, dynamically adjusting to current network latency and congestion. This Just-In-Time routing ensures maximum utilization of bandwidth with minimal overhead.
In practice, this means blob data is streamed across the network in chunks, prioritized for highest-value content, and disseminated in parallel, allowing block proposers to pre-fetch data before block creation. The result? Blazing-fast propagation and ultra-high throughput — with resilience built in.
The implementation in mamo-1 focuses specifically on the recovery phase of Vacuum!, which begins after a block is proposed. This part introduces a pull-based broadcast mechanism known as the Pull-Based Broadcast Tree (PBBT). It improves recovery throughput by:
- Pipelining "Have" and "Want" messages to minimize latency
- Distributing the block across validators, instead of relying solely on the proposer
- Allowing validators to reconstruct parts of the block from their mempools
- Using erasure coding and parity data to recover blocks without downloading them in full
These innovations enable the network to achieve high throughput even under partial data availability, and make block propagation more robust against sybil and denial-of-service attacks.
Vacuum! is a leap forward not only in performance, but also in robustness and simplicity, setting a new benchmark for peer-to-peer data dissemination in blockchains. Read the Vacuum! spec and the Recovery spec for full technical details.
Go bigger
Whether you’re building zk-rollups, verifiable web apps, or fully-onchain games, mamo-1 is the ideal environment to test at production scale. Push your apps to the limit, flood the testnet with data, and help us uncover the future of modular blockchains.
Join the conversation and tune in for the upcoming mamo-1 Twitter Space on Tuesday at 10am ET, where we’ll dive deeper into mamo-1's architecture, what's next, and how you can get involved.