rotary vs other harnesses

July 26, 2026 · View on GitHub

rotary = engine only. Telekinesis (CLI/TUI) and omi desktop are product hosts on top.

	rotary	Codex	OpenCode	t3code	Crush	pi
Role	harness library	product agent	product agent	multi-provider GUI shell	terminal agent	coding harness
Language	Rust	Rust/TS	TS	TS	Go	TS
Embeddable	yes	limited	limited	no (host)	limited	package-level
Loop + tools	yes	yes	yes	wraps providers	yes	yes
Permissions	modes + approver	sandbox + approvals	permissions	via provider	hooks	extensions
Sessions	tree fork/merge	threads/rollouts	sessions	multi-session UX	sessions	session tree
Computer-use	Praefectus embed	OS features	plugins	N/A	N/A	N/A
MCP client	yes	yes	yes	no	yes	no
Memory	graph + SQLite	context window	sessions	via provider	sessions	session tree
Skill engine	bayesian + curator	skill packages	no	no	no	no
Cost tracking	per-model registry	no	no	no	no	no
Pi compat	moved to host	no	no	no	no	native
Host protocol	JSON-RPC IPC	app-server	SDK/HTTP	WebSocket contracts	TUI-native	RPC

Taken from Codex specifically

Approvals / sandbox modes → permissions.Policy + host Approver
Non-interactive exec → rx4 exec demo surface; hosts can expose their own non-interactive command
Skills packages → plugin skill loader (SKILL.md)
Bounded context → compact + auto-compact
Tool failure hygiene → guardrails (empty turns, repeated tool failures)

Taken from t3code

Typed event boundary between runtime and UI (IPC event notifications)
Thin product shell — UI never owns agent loop logic
Provider-agnostic host — swap models without UI rewrites

Taken from OpenCode

Multi-provider model switching mid-session (set_model)
Durable local sessions
Extensibility (plugins / MCP)

Deferred (intentionally host or later)

Web/desktop multi-client pairing (t3code) — telekinesis product
Pi protocol compat (JSONL v3, RPC, extensions) — telekinesis host

Implemented in rotary (was deferred)

OS sandbox process jail via Policy.enable_os_sandbox + seatbelt/bwrap (sandbox module)