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`
`e2b/pty-e2b` (`@deepseek-ai/dsh-pty-e2b`)	E2B byte-PTY backend, remote foreground signaling, bounded terminal state, and awaited remote cleanup	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 core design lives in the persistent PTY Agent Note; the remote ownership boundary lives in the shared E2B runtime note.