What is an archive node?
- Author
- CRYPTO PORT Editorial
- Published
- Updated
- Reading time
- 4 min
In short
An archive node keeps the full state of the chain at every past point in time. It can answer questions like 'what was this address's balance three years ago', at the cost of storage an order of magnitude beyond a normal full node. Analytics and tax tools depend on exactly this.
Key points
- Retains the chain's state at every historical block
- Can query balances or contract variables at any height
- Needs storage far beyond a regular full node
- Underpins analytics, tax and audit tooling
Definition
A node that preserves the complete state as of every block, allowing balances and contract variables to be queried at any historical height.
A normal full node keeps the current state it needs for validation and drops intermediate states. In principle you could recover an old state by replaying from genesis, but not in any practical amount of time. An archive node simply keeps every state instead.
You need this to answer questions like what a DeFi pool held two years ago, or how a particular contract variable evolved. Rich explorer views, tax calculators and on-chain analytics products all sit on top of nodes like these.
The price is disk. Requirements for an Ethereum archive node vary a great deal by client implementation, but they run an order of magnitude above a standard full node. Most individuals rent access through an RPC provider rather than hosting one.
Watch out for
- · Storage needs differ sharply by client, so do not plan around one quoted figure
- · An archive node does not validate more strictly; it only makes history queryable
- · Using a hosted provider exposes what you query, which reveals what you are interested in