Developer: OpenClaw Foundation (created by Peter Steinberger) | Free Plan: Yes (free and open source; bring your own AI provider) | Starting Price: Free | Best For: Developers and power users wanting a self-hosted, privacy-focused AI assistant

Developer: Nous Research | Free Plan: Yes (free and open source; bring your own AI provider) | Starting Price: Free | Best For: Developers wanting a self-hosted AI agent that improves and remembers over time

Developer: Butterfly Effect Pte. Ltd. | Free Plan: Yes (300 daily refresh credits) | Starting Price: $20/month (Pro, 4,000 monthly credits) | Best For: Researchers and solopreneurs wanting an agent that completes multi-step tasks independently

Developer: Superhuman (formerly Grammarly) | Free Plan: No (no free tier) | Starting Price: $25/user/month billed annually (Starter) | Best For: Founders, executives, and sales teams wanting the fastest possible inbox