What they have in common
Whatever the interface, each tool drives an LLM that is stateless between sessions and bounded by a finite context window. None of them 'remembers' your project unless context is re-supplied.
So the real comparison isn't 'which one remembers' — it's how each helps you feed it the right context.
Claude Code
Claude Code runs in the terminal and works agentically — reading and editing files, running commands, and following a project memory file (CLAUDE.md) it loads each session.
Its strength is letting you encode durable conventions and decisions in that file while it fetches what it needs from the repo on demand.
Cursor
Cursor is a full IDE built around AI. It indexes your codebase for retrieval and supports project rules that persist conventions across sessions, surfacing relevant files automatically as you work.
If you prefer an editor-centric flow with built-in retrieval, that indexing is the headline feature.
Cline
Cline is an IDE-extension agent that performs explicit, reviewable actions — proposing file edits and commands step by step. You see and approve what it does.
That transparency suits people who want tighter control over each change the agent makes.
What actually decides reliability
Across all three, the agents that behave well are the ones given curated persistent memory (a context/rules file) and good retrieval — not the ones on a particular brand.
Pick the interface you like, then invest in the context engineering. That's what separates a flaky assistant from a dependable one.