`PTY` stands for **Pseudo-Terminal**（伪终端）. This capability provides persistent, owner-scoped terminal sessions for workflows that require state across tool calls or interactive stdin. PTY complements the one-shot bash and filesystem tools; it does not replace their stronger per-operation contracts.
| `pty-local` (`@deepseek-ai/dsh-pty-local`) | Local `node-pty` backend, readiness detection, bounded terminal state, sandboxing, and process-session supervision | registers on `ctx.pty` |
| `tool-pty` (`@deepseek-ai/dsh-tool-pty`) | Six model-facing tools and generic task integration for background sends | registers on `ctx.tools` |
The design and deferred boundaries live in the [persistent PTY Agent Note](../../.agents/notes/implemented/feature/2026-07-16-persistent-pty-sessions.md).
