AWS Releases Strands Harness: Open-Source Agent Harness With 28% Lower Token Cost at Comparable Accuracy

Amazon's AWS Strands Agents team has open-sourced Strands Harness, an agent evaluation and execution harness that achieves 28% lower token cost compared to baseline approaches while maintaining comparable task accuracy. The framework is designed to help developers build, test, and optimize AI agents more efficiently, directly addressing one of the most significant pain points in production agentic deployments: runaway token consumption. A 28% reduction in token cost at parity accuracy is a meaningful engineering win for any team running agents at scale, where inference costs can compound rapidly across multi-step task execution. Strands Harness joins a growing ecosystem of open-source agent tooling alongside frameworks like LangGraph and AutoGen, and its AWS provenance suggests strong integration with Bedrock and other AWS AI services. Developers should review the harness architecture to understand whether its cost reduction techniques — likely including prompt compression or smarter tool-call routing — are applicable to their existing agent stacks.