# Overview

> Private Solana mainnet RPC, Yellowstone gRPC and shred streams from bare-metal nodes in dedicated regions.

Source: https://docs.constant-k.com/get-started/

constant-k runs private Solana mainnet nodes on bare-metal servers in dedicated regions. This section covers endpoints, API keys, plan limits and the first request.

## Product by task

| Task                                                            | Product                                            | Protocol |
| :-------------------------------------------------------------- | :------------------------------------------------- | :------- |
| Read accounts, balances, blocks or transaction history          | [Solana RPC](https://docs.constant-k.com/rpc/)                                | HTTPS    |
| Read blocks older than the region's ledger with `getBlock`      | [Cube Runner](https://docs.constant-k.com/cube-runner/)                       | HTTPS    |
| Send transactions                                               | [Sending Transactions](https://docs.constant-k.com/rpc/sending-transactions/) | HTTPS    |
| Get pushed updates for a few accounts or signatures             | [WebSockets](https://docs.constant-k.com/rpc/websockets/)                     | WSS      |
| Stream filtered accounts and transactions with low latency      | [Kaldera gRPC](https://docs.constant-k.com/kaldera/)                          | gRPC     |
| See transactions before they execute, without execution results | [Turbo Kaldera (aRPC)](https://docs.constant-k.com/kaldera/turbo-kaldera/)    | gRPC     |
| Receive serialized entries, unfiltered                          | [ShredPrism](https://docs.constant-k.com/shredprism/)                         | gRPC     |

aRPC, anticipatory RPC, is constant-k's name for pre-execution transaction streaming. Plan availability per product is in the [endpoint table](https://docs.constant-k.com/get-started/endpoints/).

## Pipeline stages

Each product hands data over at a different stage between the leader and the reader, and an earlier stage arrives sooner and says less about the outcome. [Data Stages](https://docs.constant-k.com/get-started/data-stages/) sets out all six stages and the stage each product delivers at.

Turbo Kaldera and Kaldera can run side by side: Turbo Kaldera for the early notification, Kaldera for the executed result.

## Key pages

- [Quickstart](https://docs.constant-k.com/get-started/quickstart/)

- [Endpoints](https://docs.constant-k.com/get-started/endpoints/)

- [Authentication](https://docs.constant-k.com/get-started/authentication/)

- [Plans & Limits](https://docs.constant-k.com/get-started/plans-and-limits/)

- [Data Stages](https://docs.constant-k.com/get-started/data-stages/)

## Live measurements

constant-k publishes latency and node health for the same nodes that serve customer traffic. See [Benchmarks](https://www.constant-k.com/benchmarks/) and [RPC Status](https://www.constant-k.com/rpc-status/).