strands-agents/harness-sdk

Project overview

The framework provides hooks to intercept, validate, or redirect any agent step, along with backend-swapping capabilities that allow you to scale models while keeping your agent code unchanged.

Project type

AI Agent

Deployment

Refer to project documentation

License

Apache-2.0

Best for

• Developers and AI engineers who write Python or TypeScript code and need a library to build production-grade AI agents with multi-provider support.

Key capabilities

• A model-driven agent loop that traces every decision by default.
• First-class support for Amazon Bedrock, Anthropic, OpenAI, and Gemini, plus custom ones.
• Hooks to intercept any step to log it, validate it, or redirect it, allowing agents to correct themselves.
• Provides reusable tools like a calculator for agents.
• Mechanisms to catch mistakes before they run.
• Built-in support for multi-agent systems and structured output.
• Built-in MCP support.
• Built-in bidirectional streaming.

Limitations and risks

• Requires configuring model access and credentials for an external provider. Amazon Bedrock is the default provider, with Claude Sonnet as the default model. A paid external service is required for inference.
• Requires Python 3.10 or higher.
• Requires Node.js 20 or higher.

Getting started

• Installation difficulty is rated as easy, requiring simple pip or npm install commands. The first success path involves installing the package via pip and running a 3-line Agent example.

Evidence and sources

Open original GitHub project