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.

Package	Role	ctx key
`pty` (`@deepseek-ai/dsh-pty`)	Backend registry, branded ids, exact-Agent ownership, session operations, and awaited cleanup	`ctx.pty`
`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`
`tool-bash-persistent` (`@deepseek-ai/dsh-tool-bash-persistent`)	One model-facing `bash` backed by an owner-scoped reusable PTY shell	consumes `ctx.pty`, registers on `ctx.tools`

The design and deferred boundaries live in the persistent PTY Agent Note.