Hashgraph Online Standards SDK

	A lightweight SDK providing reference implementations for Hashgraph Consensus Standards (HCS) created by Hashgraph Online. This SDK is built and maintained by Hashgraph Online, a consortium of leading Hedera Organizations within the Hedera ecosystem. 📚 Standards SDK Documentation 📖 HCS Standards Documentation

Quick Start

npm install @hashgraphonline/standards-sdk

Documentation

For complete documentation, examples, and API references, visit:

Standards SDK Documentation

Interactive CLI and Demos

Launch the bundled CLI to explore registry broker demos, inspect required env vars, and run helper scripts:

pnpm run cli

The CLI surfaces:

Guided registry broker demos (OpenRouter, chat history, ledger auth) plus the HCS-10 agent flows.
A map of required env vars so you can bootstrap Hedera credentials and adapters quickly.
Links back to the docs plus the demo scripts you can run manually (demo/registry-broker, demo/hcs-10).

See cli/standards-cli/README.md for advanced and non-interactive commands.

Supported Standards

HCS-1: File Storage
HCS-2: Registry and Indexing Standard
HCS-3: Recursive File Loading
HCS-7: Smart Hashinals
HCS-10: Trustless Peer-to-Peer Communication for Agents and AI
HCS-11: Decentralized Profile and Identity Standard
HCS-20: Auditable Points

Running Demos

The SDK includes demo implementations that showcase registry broker flows (discovery, chat, ledger auth, OpenRouter) and HCS-10 agent communication. Follow these steps to run them:

Clone the repository

git clone https://github.com/hashgraph-online/standards-sdk.git
cd standards-sdk

Install dependencies
```
npm install
```
Set up environment variables
```
cp .env.example .env
```
Edit the .env file with your Hedera credentials:
```
HEDERA_ACCOUNT_ID=0.0.12345
HEDERA_PRIVATE_KEY=your_private_key_here
HEDERA_NETWORK=testnet
REGISTRY_URL=https://moonscape.tech
```
The CLI can also auto-persist agent state in .env if a demo is interrupted. See .env.example for generated state fields.
Start a demo (or use pnpm run cli for an interactive launcher):
```
npm run demo:registry-broker
```
```
npm run demo:hcs-10
```

Each demo directory contains README instructions plus you can review demo/registry-broker and demo/hcs-10 for fine-grained scripts covering OpenRouter, history snapshots, ledger authentication, and fee flows.

Demo Descriptions

Inscribe Demo

The inscribe demo (demo/inscribe-demo.ts) showcases different file inscription capabilities:

Text inscription using buffers
URL-based inscriptions
File buffer inscriptions
Creating Hashinal NFTs from URLs
Creating Hashinal NFTs from buffers
Creating Hashinal NFTs from text content

Each inscription demonstrates different options and metadata capabilities.

HCS-10 AI Agent Communication Demo

The HCS-10 demo (demo/hcs-10/index.ts) demonstrates trustless peer-to-peer communication between AI agents:

Agent creation and registration (Alice and Bob)
Agent metadata and profile management
Connection establishment between agents
Sending and retrieving small messages
Sending and retrieving large messages with recursive storage
Message data processing
Resumable agent creation: If agent creation is interrupted, the SDK automatically resumes from where it left off using state saved in environment variables

The demo automatically handles agent funding, topic creation, and registration with the global registry. Agent creation progress is tracked in real-time and saved to the .env file, allowing recovery from any interruption.

Contributing

Please read our Contributing Guide and Code of Conduct before contributing to this project.

For bugs and feature requests, please use the issue templates.

Security

For security concerns, please refer to our Security Policy.

Maintainers

See MAINTAINERS.md for a list of project maintainers.

Resources

License

Apache-2.0