# Data Availability

**Data Availability (DA)** is a critical part of any rollup system. It ensures that all the transaction data behind a rollup’s state changes is publicly accessible - allowing anyone to verify the rollup’s correctness and reconstruct the current state.

Without secure DA, a rollup could claim a new state root without revealing how it got there - making it impossible to independently verify or challenge.

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#### How Solaxy Handles DA

Solaxy uses a **modular data availability layer**, giving it the flexibility to balance security, performance, and cost depending on the environment.

**Primary DA Layer: Solana L1**

For production and high-trust environments, Solaxy publishes transaction data and proofs directly to **Solana Layer 1**. This inherits the strong security guarantees of Solana’s consensus and validator set.

Benefits:

* Secure, censorship-resistant data storage
* Transparent and verifiable by anyone
* Long-term archival persistence

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**Optional DA Layer: Celestia**

For performance testing, alternative configurations, or cost-sensitive applications, Solaxy can optionally publish data to **Celestia**, a dedicated modular DA network.

Benefits:

* Lightweight DA layer optimized for throughput
* Lower publishing costs for large data batches
* Separation of execution and data roles

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#### DA Modes in Solaxy

Solaxy supports multiple DA strategies:

* **Inline Posting (to Solana L1):** Data is posted alongside proofs during settlement.
* **External Posting (e.g. Celestia - Not implemented yet):** Data is committed to a secondary layer with references anchored on Solana L1.

In both cases, Solaxy ensures:

* All necessary transaction data is retrievable
* Validators, light clients, and users can independently verify rollup behavior

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#### Future DA Enhancements

Solaxy’s modular architecture will allow support for additional DA layers and innovations, such as:

* **Shared DA markets**
* **Erasure-coded storage**
* **Reed-Solomon fallback proofs**
* **Fraud-proof-based DA guarantees**

This flexibility allows Solaxy to evolve alongside the broader modular blockchain ecosystem.