harness-sdk

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  <div>
    <a href="https://strandsagents.com">
      <img src="https://strandsagents.com/latest/assets/logo-github.svg" alt="Strands Agents" width="55px" height="105px">
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  <h1>
    Strands Agents
  </h1>

  <h2>
    A model-driven approach to building AI agents in just a few lines of code.
  </h2>

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  <p>
    <a href="https://strandsagents.com/">Documentation</a>
    ◆ <a href="https://github.com/strands-agents/samples">Samples</a>
    ◆ <a href="https://github.com/strands-agents/tools">Tools</a>
    ◆ <a href="https://github.com/strands-agents/agent-builder">Agent Builder</a>
    ◆ <a href="https://github.com/strands-agents/mcp-server">MCP Server</a>
  </p>
</div>

Strands Agents is a simple yet powerful SDK that takes a model-driven approach to building and running AI agents. From simple conversational assistants to complex autonomous workflows, from local development to production deployment, Strands Agents scales with your needs.

This monorepo contains the Python SDK, TypeScript SDK, documentation site, and supporting packages:

| Directory | Description |
|-----------|-------------|
| `strands-py/` | Python SDK: agent loop, model providers, tools ([PyPI](https://pypi.org/project/strands-agents/) · [releases](https://github.com/strands-agents/harness-sdk/releases?q=python%2F&expanded=false)) |
| `strands-ts/` | TypeScript SDK: agent loop, model providers, tools ([npm](https://www.npmjs.com/package/@strands-agents/sdk) · [releases](https://github.com/strands-agents/harness-sdk/releases?q=typescript%2F&expanded=false)) |
| `strands-wasm/` | WebAssembly bindings for running Python tools from TypeScript agents |
| `strands-py-wasm/` | Python host for WASM components (bridges WIT interfaces to Python) |
| `strandly/` | Developer CLI for local builds, codegen, and workspace tooling |
| `site/` | Source for the [strandsagents.com](https://strandsagents.com) documentation site (Astro/Starlight) |
| `designs/` | Design proposals for significant features (RFC-style) |

## Why Strands

Build an agent harness. Control it end-to-end.

- **Build your way.** Any model, any cloud. Context management, execution limits, and observability built in before you write a line of config. Swap backends when you scale; your code stays the same.
- **Model agnostic.** First-class support for Amazon Bedrock, Anthropic, OpenAI, and Gemini, plus [many more providers](https://strandsagents.com/docs/user-guide/concepts/model-providers/) and custom ones.
- **Stay in control.** The agent loop traces every decision by default. Hooks let you intercept any step to log it, validate it, or redirect it.
- **Deliver outcomes that work.** Guardrails catch mistakes before they run. Steering handlers let agents correct themselves instead of failing silently.

MCP, streaming, multi-agent patterns, and structured output are all built in.

## Quick Start

Both SDKs default to the Amazon Bedrock model provider, so you'll need AWS credentials configured and model access enabled for Claude Sonnet. The [Quickstart Guide](https://strandsagents.com/docs/user-guide/quickstart/overview/) covers configuring other providers (Anthropic, OpenAI, Gemini, Ollama, and more).

### Python

Requires Python 3.10+:

```bash
pip install strands-agents strands-agents-tools
```

```python
from strands import Agent
from strands_tools import calculator

agent = Agent(tools=[calculator])
agent("What is the square root of 1764")
```

The [Python SDK README](strands-py/) covers tools, model providers, MCP, and bidirectional streaming.

### TypeScript

Requires Node.js 20+:

```bash
npm install @strands-agents/sdk
```

```typescript
import { Agent } from '@strands-agents/sdk'

const agent = new Agent()
const result = await agent.invoke('What is the square root of 1764?')
console.log(result)
```

More in the [TypeScript SDK README](strands-ts/), including Zod-typed tools, structured output, and multi-agent patterns.

## Documentation

For detailed guidance & examples, explore our documentation:

- [User Guide](https://strandsagents.com/)
- [Quick Start Guide](https://strandsagents.com/docs/user-guide/quickstart/overview/)
- [Agent Loop](https://strandsagents.com/docs/user-guide/concepts/agents/agent-loop/)
- [Examples](https://strandsagents.com/docs/examples/)
- API Reference: [Python](https://strandsagents.com/docs/api/python/strands.agent.agent/) · [TypeScript](https://strandsagents.com/docs/api/typescript/)
- [Production & Deployment Guide](https://strandsagents.com/docs/user-guide/deploy/operating-agents-in-production/)

The docs themselves live in this monorepo under [`site/`](site/), and doc PRs are welcome alongside code changes.

## Development

Git operations (commits, branches, PRs) are done from the repo root. Each package has its own toolchain:

**Python SDK** (`strands-py/`):
```bash
cd strands-py
pip install hatch
hatch test        # run unit tests
hatch fmt         # format & lint
```

**TypeScript SDK** (`strands-ts/`):
```bash
npm ci            # install from repo root
npm run build     # build
npm test          # run unit tests
```

**Documentation site** (`site/`):
```bash
cd site
npm install
npm run dev       # local dev server at http://localhost:4321/
```

## Contributing ❤️

We welcome contributions! See our [Contributing Guide](CONTRIBUTING.md) for details on:
- Reporting bugs & features
- Development setup
- Contributing via Pull Requests
- Code of Conduct
- Reporting of security issues

## Stay in touch with the team
Come meet the Strands team and other users on [**Discord**](https://discord.com/invite/strands)

## License

This project is licensed under the Apache License 2.0 - see the [LICENSE.APACHE](LICENSE.APACHE) file for details.

## Security

See [CONTRIBUTING](CONTRIBUTING.md#security-issue-notifications) for more information.