# Synchronization

Synchronization brings the local node in sync with the network and feeds ready blocks into consensus.

## Phases

Archive and full nodes follow a fixed phase pipeline:

1. CatchUpRecoverBlockHeaderFromDB
2. CatchUpSyncBlockHeader
3. CatchUpCheckpoint
4. CatchUpFillBlockBodyPhase
5. CatchUpSyncBlock
6. Normal

Each phase drives specific network requests and graph updates.

## SynchronizationGraph

The sync graph stores all received headers and blocks and tracks their status:

* Header-only, graph-ready, block-ready.
* Parent and referee connectivity.
* Frontiers for not-ready blocks and old-era blocks.

Only blocks that are graph-ready and have full bodies are delivered to consensus.

## State sync

Snapshot-based state sync uses:

* Snapshot manifest requests.
* Chunk requests/responses.
* Candidate selection and restoration helpers.

## Key source files

* `crates/mazzecore/core/src/sync/synchronization_phases.rs`
* `crates/mazzecore/core/src/sync/synchronization_graph.rs`
* `crates/mazzecore/core/src/sync/message/mod.rs`
* `crates/mazzecore/core/src/sync/state/mod.rs`