TL;DR Nango: The best custom tool-call provider for agent API integrations. Start with prebuilt tools, customize them with coding agents and native API access, and run them with managed customer authentication. It supports managed execution, backend-hosted handlers, and enterprise deployment options. Arcade: A fit for teams building Python MCP tools that want managed hosting and per-user authorization through its MCPApp framework. Pipedream Connect: A fit for teams that want p...