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Shred Format
Solana shreds are the fundamental units of block data propagation. Understanding their format helps you build efficient parsers and processors.
Overview
Each UDP packet you receive contains a single shred. Shreds are binary-encoded with a maximum size of 1,228 bytes (payload) plus headers.
Shred Types
- Data Shreds — Contain actual transaction data fragments
- Coding Shreds — Reed-Solomon erasure coding for recovery
Header Layout
| Offset | Size | Field | Description |
|---|---|---|---|
| 0 | 64 bytes | Signature | Ed25519 signature of the shred |
| 64 | 1 byte | Shred Variant | Type indicator (data or coding) |
| 65 | 8 bytes | Slot | The slot this shred belongs to |
| 73 | 4 bytes | Index | Index within the slot |
| 77+ | Variable | Payload | Shred data payload |