OpenSeek
An open-source terminal coding agent with Plan, Agent and YOLO modes, MCP and LSP support, and bring-your-own-key routing across 28 built-in model providers with a transparent cost meter.
OpenSeek is a TUI coding agent offering the same agentic terminal experience as Claude Code or Codex but open source, with full bring-your-own-key freedom across 28 built-in providers spanning OpenAI-compatible services, Anthropic-protocol providers, Google Gemini and local backends such as Ollama. Plan, Agent and YOLO modes move from read-only planning through confirmed execution to full autonomy.
It ships more than 50 tools and 100-plus slash commands covering file operations, shell, web search, MCP fan-out and sub-agents, an MCP client over stdio, SSE and WebSocket transports, and inline diagnostics from language servers such as tsserver, rust-analyzer, pyright and gopls during edits. A headless HTTP/SSE runtime API supports IDE bridges and CI, and a cost meter tracks per-model spend and cache-hit accounting. It requires Bun at runtime and runs on macOS and Linux, or WSL2 on Windows.