Cydonia

A terminal client for ACP agents — connect any coding agent that speaks the Agent Client Protocol and chat with it full-screen in your terminal.

 ╭────────────────────────────────────────────────────────────────╮
 │ Cydonia — claude — Ctrl+D to exit, /help for keys              │
 │ agent  Claude Agent 0.68.0 · acp v1                            │
 │ mode   auto (Auto, Manual, Accept Edits, Plan Mode, …)         │
 │ cwd    ~/code/cydonia                                          │
 ╰────────────────────────────────────────────────────────────────╯

 fix the flaky test in ci

⏺ Read tests/e2e.rs
  ⎿ 212 lines

⏺ The retry loop races the server startup — pinning the port fixes it.

┌ claude > ──────────────────────────────────── Fix flaky e2e test ─┐
│>                                                                  │
└───────────────────────────────────────────────────────────────────┘

Usage

cargo install --path apps/tui
cydonia

Pick an agent from the selector and chat. Cydonia renders streamed markdown, reasoning, tool calls, and the agent's plan; permission requests pop up as a modal; fs/read_text_file and fs/write_text_file are served to the agent.

Key	Action
Enter	send (Shift+Enter for a newline)
/	slash commands, including the agent's own (Tab to complete)
Ctrl+C	cancel the current turn
PageUp / PageDown	scroll the transcript
Ctrl+D or /exit	quit

Agents

~/.config/cydonia/settings.toml is generated on first run and never needs hand-maintenance — it's seeded with the Claude Code and Codex adapters. Any ACP agent is an entry away:

[[agents]]
name = "my-agent"
command = "path/to/agent"
args = ["--acp"]
# env = { KEY = "VALUE" }

Set CYDONIA_DEBUG=/tmp/acp.log to capture the raw JSON-RPC wire.

Layout

Crate	Purpose
crates/core	settings + the ACP session (executor-neutral, no UI deps)
crates/registry	the ACP and MCP registries, and the installer for both
apps/tui	the terminal frontend (ratatui)
apps/gpui	the desktop frontend (GPUI), on the same core

Docs

docs/ is an mdBook covering commands, agents, MCP servers, and — worth reading before relying on it — the limitations.

mdbook serve docs --open

License

MIT