Which Sia software do I need?

A side-by-side guide to the Sia software and the terms used across these docs.

There are several pieces of Sia software, each for a different job. Use this page to find the one that matches what you want to do.

I want to…	Use
Store and manage files the easy way	The Sia Storage app (desktop, mobile) with a Sia Storage account — 50 GB free
Use Sia through an S3-compatible API	s3d, connected to an indexer such as Sia Storage
Build my own app	The Sia Storage SDKs
Run the indexer myself instead of using Sia Storage	indexd — requires PostgreSQL
Provide storage and earn Siacoin	hostd
Hold and manage Siacoin	walletd
Run the older all-in-one renter	renterd — no longer the preferred way to store data

How the pieces fit together

To store data on Sia you run a client that connects to an indexer. The client encrypts your files and moves them to and from storage providers; the indexer manages contracts and keeps your data healthy. By itself, an indexer like Sia Storage doesn't store your files — you need a client to use it. See About Storing Your Data for more.

Clients — how you use Sia storage

• Sia Storage app — desktop and mobile apps for storing and retrieving files. Point it at an indexer; a Sia Storage account is the easiest option.

• s3d — a lightweight, S3-compatible gateway. It translates the AWS S3 API to Sia and connects to an indexer such as Sia Storage, so existing S3 tools and applications can use Sia storage.

• Sia Storage SDKs — client libraries (Rust, Go, Python, JavaScript) for building your own app. The Sia Storage app and s3d are currently the only ready-made clients.

Indexer — the backend

• Sia Storage — a hosted indexer. It manages contracts and keeps your data healthy for you, with 50 GB free and nothing to run. Recommended for most people.

• indexd — the indexer software, for running the backend yourself instead of using Sia Storage. Requires PostgreSQL.

Other software

• hostd — storage-provider software. Stores encrypted data for the network and earns Siacoin.

• walletd — a standalone wallet for Siacoin and Siafunds, with Ledger support.

• renterd — the original all-in-one renter (wallet, contracts, and an upload/download UI in one program). Still works, but no longer the preferred way to store data.

Glossary

• Renter — anyone storing data on Sia. The renter forms and pays for storage contracts; today an indexer fills this role on your behalf.

• Storage provider (host) — an operator running hostd that stores encrypted data and earns Siacoin.

• Client — software you run to store and retrieve files, such as the Sia Storage app or s3d. A client connects to an indexer.

• Indexer — the backend that manages contracts, tracks where data lives, and keeps it healthy. Sia Storage is a hosted indexer; indexd is the software for running your own.

• Contract — a blockchain-enforced agreement between a renter and a storage provider covering how much data to store, for how long, and at what price.

• Object — the application-level view of a stored file: its data, metadata, and storage layout under a single content-derived ID.

• Slab — a unit of an object's data that is erasure-coded into shards.

• Shard — one erasure-coded, encrypted piece of a slab, stored by a single provider.

• Erasure coding — a method of splitting data into redundant pieces so the original can be rebuilt from a subset of them.

• Siacoin (SC) — the network's utility token, used to pay for storage.

• Siafund — a separate token that receives a fee from storage contracts.

• Recovery phrase (seed) — the secret words that control a wallet and let you recover it.