Harness² vs Anything API
Side-by-side comparison of features, pros & cons, pricing, and community votes (2026).
🏆 Anything API leads with 672 upvotes

Harness the agent. Then harness its self-improvement.
Harness² from Google Research is an innovative plug-and-play framework designed for developing and evolving autonomous AI agents. It leverages dual recursion—task-level propose-probe-compose refinement and harness-level accumulation of reusable experience—to enable large language model (LLM) agents to improve their execution strategies over time without the need for ground-truth verifiers. This self-improving architecture allows agents to adapt dynamically to open-world tasks, making it ideal for complex, evolving environments. By automating the evolution of prompts, tools, and memory, Harness² enhances agent performance and robustness, pushing the boundaries of autonomous AI development. Its open source nature and emphasis on self-improvement make it particularly appealing to researchers, developers, and AI practitioners seeking cutting-edge, adaptable agent frameworks.
Pros
- Enables autonomous evolution of agent prompts, tools, and memory
- Dual recursion approach improves agent adaptability and performance
- No ground-truth verifiers needed, simplifying setup
- Open source and easily integrable into existing workflows
- Demonstrates significant benchmark improvements (+11.5 points)
Cons
- Complex setup may require advanced understanding of recursive frameworks
- Limited user interface or pre-built integrations
- Performance depends on the quality of initial configurations
Best for
- • Developing autonomous agents for open-world exploration
- • Enhancing AI assistants with self-improving capabilities
- • Automating complex decision-making processes
- • Research on agent self-optimization and reinforcement learning
Pricing: Pricing not verified

Any website. We deliver the API.
Anything API is an innovative platform that bridges the gap for websites lacking public APIs. It empowers users to convert their browser-based interactions into robust, production-ready APIs without extensive coding. By simply describing the task, users can have custom functions built that directly call the target website, enabling seamless integration and automation. These custom API endpoints can be deployed serverless, scheduled via Cron, or accessed through standard API calls, making it highly versatile for developers, automation enthusiasts, and businesses seeking to extend functionality of web services. Its unique approach of translating manual browser work into programmable endpoints distinguishes it from traditional API providers, offering a flexible solution for accessing data or automating tasks on virtually any website.
Pros
- Transforms any website into a custom API without coding
- Flexible deployment options including serverless and scheduled tasks
- User-friendly task description process simplifies API creation
- Supports automation and integration with existing systems
- Highly versatile for various web scraping and data extraction needs
Cons
- Limited details on pricing structure and plans
- Potential challenges with highly dynamic or complex websites
- Reliance on agent-generated functions may require occasional updates
Best for
- • Extracting data from websites lacking public APIs
- • Automating repetitive browser tasks through API calls
- • Building integrations for custom web workflows
- • Monitoring website changes or content updates
Pricing: Likely operates on a pay-as-you-go or subscription-based model, with possible tiered plans depending on usage volume and features. Specific pricing details are not publicly disclosed, suggesting a custom or variable pricing approach.