> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chainstack.com/llms.txt
> Use this file to discover all available pages before exploring further.

<AgentInstructions>

## Submitting Feedback

If you encounter incorrect, outdated, or confusing documentation on this page, submit feedback:

POST https://docs.chainstack.com/feedback

```json
{
  "path": "/docs/request-units",
  "feedback": "Description of the issue"
}
```

Only submit feedback when you have something specific and actionable to report.

</AgentInstructions>

# Request units (RUs)

> Understand how Chainstack measures and consumes request units across EVM, Solana, TON, and other protocols for accurate usage tracking and billing.

## What are request units?

Request unit (RU) is a metric that measures the size and complexity of request processing for Chainstack request‑based services.

## Why request units are used for pricing?

In the Web3 ecosystem, certain requests can require more extensive data processing or involve complex computations and higher spending of resources. Such requests consume more RUs. This aligns pricing with actual resource consumption.

See current service pricing on the [pricing page](https://chainstack.com/pricing/).

## Base rules

* Full node request: 1 RU
* Archive node request: 2 RUs

These rules apply consistently unless noted below for specific protocols.

## EVM protocols

* Full node calls against the latest state: 1 RU.
* Archive state requests (historical state at a past block): 2 RUs.
* Debug and trace APIs: 2 RUs per call (require archive state).

### Archive state methods

These methods are billed at 2 RUs when called against a block older than \~128 blocks from the tip:

* `eth_getBalance`
* `eth_getCode`
* `eth_getTransactionCount`
* `eth_getStorageAt`
* `eth_call`
* `eth_getProof`
* `eth_callMany`
* `eth_createAccessList`

Calls targeting `latest`, `pending`, or a recent block within the \~128-block window are billed at 1 RU.

<Note>
  The exact threshold may vary slightly by network but is approximately 128 blocks for most EVM networks on Chainstack.
</Note>

### Debug and trace methods

All `debug_*` and `trace_*` methods — including `debug_traceTransaction`, `debug_traceBlockByNumber`, and `trace_block` — are billed at 2 RUs per call, as they require archive state.

For debug and trace capabilities by protocol, see [debug & trace APIs](/docs/debug-and-trace-apis).

## Solana

* A Solana full node keeps about 1.5 days of full block data. Requests within that horizon are consumed as 1 RU.
* Anything beyond that horizon is an archive call and is consumed as 2 RUs.
* Only specific Solana methods can fetch archive data. See the list under [Solana archive methods availability](/docs/limits#solana-archive-methods-availability).

## TON

There is no difference between full and archive requests. All data is always available, and every request is consumed as 1 RU.

## All other protocols

* Full node request: 1 RU
* Archive request: 2 RUs