Cosine vs. Letta Code

Feature	Cosine	Letta Code

Tagline	Your coding agent in your terminal.	The memory-first coding agent
Website	https://cosine.sh/cli	https://letta.com
Language	go	typescript
Release Date		December 16, 2025
Last Updated	September 4, 2026	August 19, 2026
Provider Type	AI Lab	Independent
MCP Support	Yes	Yes
Multi-Agent Support	Yes	Yes
Git Integration	deep	basic
Multi-File Editing	Yes	Yes
Auto Test Running	Yes	Yes
Sandbox / Permissions	Yes	Yes
Image / Multimodal Input	Yes	Yes
Voice Mode	No	No
IDE Integration	VS Code	None - Terminal only
Hooks / Extensions	Yes	Yes
Web Search	Yes	Yes
Local Model Support	No	Yes
Context Window	Model dependent	Model-dependent
Terminal Bench 2.0		#48 · 59.1% ±2.4 ²
Supported Models	Lumen Scout, Lumen Outpost; GPT-5.5/5.4, Claude Opus 4.7/4.6, Claude Sonnet 4.6, Gemini 3.1 Pro, Gemini 3 Flash, Kimi K2.6, GLM 5.1, MiniMax M2.7, Qwen 3.6 Plus, DeepSeek v4 Pro	Multi-provider with Claude, GPT, Gemini and self-hosted (BYOK).
Supported Subscriptions	—	ChatGPT GitHub Copilot Claude Code OpenCode Go / Zen
Pricing Model	Usage Based, Freemium, Subscription	Freemium
Free Tier	No	Yes
Price Range	$19-999/mo	Free (BYOK) / $20-200/mo
Source Code Availability	Proprietary Software	Open Source (Apache-2.0)
Source Code	N/A	c
Development State	active	active