Cline, released in 2024 and originally built under the name Claude Dev before its current rebrand, runs as a VS Code extension built around a specific trust-building design choice: before editing a file or running a terminal command, it shows exactly what it's about to do and waits for approval, rather than making changes autonomously and presenting a finished diff afterward.
That approve-before-acting workflow, combined with being model-agnostic rather than locked to one AI provider, has made it a favorite among developers who want agentic capability without giving up visibility into what's happening at each step. Cline was also an early adopter of the Model Context Protocol, letting it connect to external tools and data sources in a standardized way.
Cline is free and open source, with model API costs paid separately depending on the provider connected. For a developer who wants an agentic coding assistant that explains itself before acting rather than working as a black box, Cline's transparent, approval-based workflow is a specific design choice that sets it apart from more fully autonomous competitors.
