Caret, T3 Code and Cursor

Three different shapes. Caret is an editor with the agent layer built in: one Rust process, the system WebView, your own keys and subscriptions. T3 Code is an open-source control surface for coding agent harnesses such as Claude Code and Codex, with threads and worktrees but no editor by design. Cursor is an Electron editor whose agent runs through Cursor's backend. The tables below mark what each one ships today.

Legend:Yes shippedPartial partial, or only in some plansNo not available

Editor

Feature	Caret	T3 Code	Cursor
Code editor with LSP T3 Code is a harness control surface without an editor by design.	Yes	No	Yes
Tab completions	Yes	No	Yes
Inline edit (Cmd K) with streaming diff	Yes	No	Yes
Debugger (DAP)	Yes	No	Yes
Terminal with command blocks and AI fix-it	Yes	Partial	Partial
Codebase index with local embeddings	Yes	No	Yes

Agents and subscriptions

Feature	Caret	T3 Code	Cursor
Built-in agent with your own API keys Cursor routes through its own backend.	Yes	No	Partial
Claude Code subscription	Yes	Yes	No
ChatGPT subscription via Codex	Yes	Yes	No
Cursor subscription	Yes	Yes	Yes
Grok Build	Yes	Yes	No
Gemini CLI, OpenCode, Pi	Yes	Partial	No
Any Agent Client Protocol agent	Yes	Yes	No
Local models (Ollama, LM Studio, vLLM)	Yes	No	Partial
Auto routing across your own models	Yes	No	Partial
Second account per provider (separate config home)	Yes	Yes	No

Threads and workflow

Feature	Caret	T3 Code	Cursor
Pin, snooze, settle, archive with undo	Yes	Yes	No
Queue or steer while a turn runs	Yes	Yes	Partial
Permission modes per thread and per project	Yes	Yes	Yes
Provider handoff mid-thread and forks	Yes	Yes	No
Multi-model fan-out, one worktree each	Yes	Yes	Yes
Worktree per thread with cleanup policies	Yes	Yes	Partial
Usage page across providers	Yes	Yes	Partial
Desktop notifications	Yes	Yes	Yes
Orchestrator MCP endpoint	Yes	Yes	No

Safety

Feature	Caret	T3 Code	Cursor
Shell command classifier (AST) before every run	Yes	No	No
OS sandbox (Seatbelt, bubblewrap) around agent commands, including external agents	Yes	No	Partial
Verified diffs after each turn	Yes	No	No

Remote

Feature	Caret	T3 Code	Cursor
Headless server with web client (LAN or Tailscale)	Yes	Yes	No
Mobile app	No	Yes	Partial
Hosted relay or cloud agents	No	Yes	Yes

Footprint

Feature	Caret	T3 Code	Cursor
No bundled Chromium, no Node at run time	Yes	No	No
Open source	Yes	Yes	No

Rows describe shipped behaviour as of November 2026. If one is out of date, open an issue.

Measured on a release build

Apple Silicon Mac, release bundle, demo workspace. The method and the full tables are in the performance doc.

~110 MB

Rust core RSS, idle with a workspace open

~330 ms

first paint

8 ms

quick open

33 ms

project search

The whole process family (Rust core plus the WebKit helper processes) with a TypeScript file and a terminal open is about 490 MB, versus about 393 MB for Cursor idle with one workspace open on the same machine. The remaining gap is the WebKit content process, where Monaco, xterm and React live.

T3 Code is an Electron app. We have not measured it, so this page makes no claim about its footprint. The steps in Performance work for any desktop app: launch it, list its process family with ps, and add up the RSS column.

Try it with the agent you already pay for

macOS, Windows and Linux builds on every release. MIT licensed.

Download GitHub