# ar.io Documentation

> ar.io is the access and naming layer for Arweave (permanent storage), with protocol execution on Solana.

## Resources

- [SKILL.md (structured agent reference)](/SKILL.md): Concise SDK patterns, code recipes, ArNS URL conventions, constants, and API reference for building on ar.io. Start here for code generation.
- [Full documentation text](/llms-full.txt): Complete content from all documentation pages for deep context.
- [AI agents & LLMs guide](/build/agents): All machine-readable entry points, how they differ, and how to point an agent at ar.io.
- [Testnet sandbox](/build/testnet): Free Solana devnet environment (upload, payment, ArNS, gateway) for testing without real money or permanent data.
- [ar.io SDK reference](/sdks/ar-io-sdk): TypeScript SDK for ArNS names, gateways, staking.
- [Turbo SDK reference](/sdks/turbo-sdk): Upload files and folders to Arweave.
- [Wayfinder SDK reference](/sdks/wayfinder): Decentralized data fetching with verification.
- [Gateway API reference](/apis/ar-io-node): HTTP endpoints for data retrieval, ArNS resolution, and more.
- [ArNS naming system](/learn/arns): Human-readable names for permanent data.
- [For Solana developers](/learn/solana-developers): Quick-start guide mapping Solana concepts to ar.io.

## Per-SDK plain text

- [/sdks/ar-io-sdk/llm.txt](/sdks/ar-io-sdk/llm.txt): ar.io SDK reference only.
- [/sdks/turbo-sdk/llm.txt](/sdks/turbo-sdk/llm.txt): Turbo SDK reference only.
- [/sdks/wayfinder/llm.txt](/sdks/wayfinder/llm.txt): Wayfinder reference only.
- [/sdks/ardrive-core-js/llm.txt](/sdks/ardrive-core-js/llm.txt): ArDrive Core JS reference only.

## Quick Facts

- ARIO is an SPL Token on Solana (6 decimals)
- ANTs (Ar.io Name Tokens) are Metaplex Core NFTs
- ArNS names resolve as subdomains on every gateway: `yourname.ar.io`
- Undernames use underscores, not dots: `docs_yourname.ar.io`
- SDK: `npm install @ar.io/sdk @solana/kit`
- Turbo: `npm install @ardrive/turbo-sdk`
- Files under 100 KiB upload free via Turbo
- Test for free on Solana devnet at `https://ar-io.dev` (see the testnet sandbox above)