> For the complete documentation index, see [llms.txt](https://relationlabs.gitbook.io/protocol/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://relationlabs.gitbook.io/protocol/contract-open-standard/overview.md).

# Overview

The Contract Open Standard is a smart contract specification defined by the Relation Protocol. It has two basic requirements:

* The contracts should conform to the data format and interface specification defined by the [Open Standard API](/protocol/open-standard-api/introduction.md).
* The RDF data constructed by these contracts should conform to the [Schema Standard](/protocol/schema-standard/overview.md).

Relation Protocol defined a set of Base Contracts based on the Contract Open Standard to address the three following scenarios.

**Identity**: Describe users' identity via SBT contracts.

* Name Service contract

**Relationships**: Describe connections between different users via SBT contracts.

* Follow
* DAO

**Publication**: Describe users' public or privacy content published via SBT contracts.

* Content
* Privacy Content

<figure><img src="/files/kViKB9C5boZkjib5jUKY" alt=""><figcaption><p>Figure 5-1 Base Contracts</p></figcaption></figure>