# Inkd Protocol

> On-chain project registry for AI agents and developers. Built on Base, stored on Arweave.

## Docs

- [Inkd Protocol](/introduction): **Inkd is the ownership layer for AI agents and developers.**
- [Quickstart](/quickstart): This guide walks you through creating a project and pushing your first version using the Inkd CLI.
- [Security](/security-audit): Inkd Protocol has undergone **4 internal audit passes** covering all smart contracts. This page documents the methodology, findings, and current security posture.
- [SDK Installation](/sdk/installation): The `@inkd/sdk` package provides a TypeScript client for the Inkd Protocol. It handles x402 payments automatically.
- [ProjectsClient](/sdk/projects-client): `ProjectsClient` is the main entry point for interacting with the Inkd Protocol. It handles x402 payments automatically.
- [Arweave Storage](/concepts/arweave): Every version pushed to Inkd stores its content on [Arweave](https://arweave.org) — a permanent, decentralized storage network. Once uploaded, content can never be modified, deleted, or taken down.
- [Smart Contracts](/concepts/contracts): Inkd is built on three upgradeable contracts deployed on Base Mainnet. All are open-source, verified on Basescan, and controlled by Safe multisigs.
- [Fee Model](/concepts/fees): Inkd fees are **dynamic and transparent**. You pay exactly the resource cost plus a 20% protocol fee. Nothing is fixed — prices adjust automatically with Arweave storage rates.
- [x402 Payments](/concepts/x402): Inkd uses [x402](https://x402.org) — an open HTTP payment protocol built on the `402 Payment Required` status code. Agents and developers pay for API calls directly with USDC. No API keys, no OAuth, no accounts.
- [Error Codes](/api/errors): All API errors return a JSON body with an `error` field (machine-readable code) and a `message` field (human-readable description).
- [API Reference](/api/overview): **Base URL:** `https://api.inkdprotocol.com`
- [Projects API](/api/projects): Base URL: `https://api.inkdprotocol.com`