Per-session policy overrides (sandbox/mode, approval/policy) never crossed the delegation boundary: a spawn child of a read-only-switched parent ran under the wider deployment default, and a fork child missed any switch made after its seed boundary — delegation was a bypass channel for a user's tightening. The in-process driver now snapshots the delegating parent's override chain and stamps it onto the child through the canonical write paths (SandboxPolicyService.inheritOverride / ApprovalService.inheritOverride), anchored inside the child's first turn via a one-shot agent/prompt-submit listener: turn-enclosed (durable), ahead of the first request (an inherited 'never' reaches the child's first system prompt), and positioned after any stale fork-seed switch so the ordinary last-event-wins fold resolves it. Only overrides are copied — an unswitched parent stamps nothing and the child follows the live deployment default; both services are consumed opportunistically, so compositions without them delegate unchanged. Nesting composes by construction (each stamp folds the already-stamped parent log). Evidence: inheritance.spec.ts drives scripted-model children into the real dsh-fs-sandbox fence through the real write tool (disk-state + denial-marker assertions; spawn, stale-seed fork, grandchild, escalation fail-closed, and no-stamp guards), inheritOverride contract tests in both service suites, and the recorded subagent-sandbox-inheritance ACP snapshot (read-only preset → delegate → child denied, replayed keylessly). See .agents/notes/implemented/feature/2026-07-25-subagent-policy-inheritance.md.
Examples
Runnable demos (not workspaces) that showcase how the harness is wired. Each example is a thin leaf: a cordis.yml that picks swappable backends, loads one app package, and may add optional product tools. The composition and boot glue live in @deepseek-ai/dsh-tui-demo, @deepseek-ai/dsh-cli-demo, @deepseek-ai/dsh-acp-demo, and their shared @deepseek-ai/dsh-agent-spine-demo bundle. There is no start.ts; the demo:* scripts invoke each app package's bin.
headless-agent
A non-interactive agent demo that accepts one positional task, runs one complete model/tool turn on the @deepseek-ai/dsh-cli-demo app, persists a fresh session, prints text, json, or stream-json, and exits.
Run with: pnpm run demo:headless "task" (needs DEEPSEEK_API_KEY). See headless-agent/README.md for the output contract, safety boundaries, and snapshot suite.
tui-agent
The interactive coding agent: DeepSeek V4, filesystem and bash tools, subagents, workflows, todo_write, compaction, and the full-screen TUI. It is also the home of TUI PTY and snapshot scenarios.
Run with: pnpm run demo:tui (needs DEEPSEEK_API_KEY). Run its Code Mode overlay with pnpm run demo:code-mode. See tui-agent/README.md for controls and composition.
jsonrpc-agent
An unattended coding agent driven through the Python SDK: JSON-RPC stdio, foreground-only bash, read / write / edit, one foreground subagent, todo_write, JSONL persistence, and compaction. It excludes terminal UI, stdout logging, approvals, skills, and background task controls. See jsonrpc-agent/README.md.
cordis-agent
The self-referential demo: the coding spine plus @deepseek-ai/dsh-tool-cordis, whose three tools (cordis_inspect / cordis_mount / cordis_unmount) let the agent inspect the live cordis runtime it runs inside, mount model-written plugins into it (an event listener, a brand-new tool for itself, or a service another mount injects), and dispose them again — all dynamic mounts grouped under one cordis-dynamic fiber subtree. The ctx.fs/ctx.web services ride along provider-only, as the capabilities those plugins build on.
Run with: pnpm run demo:cordis (needs DEEPSEEK_API_KEY). See cordis-agent/README.md for the staged demo script and the toolset Agent Note for the design and sandbox caveats.
acp-agent
An agent demo exposed as an Agent Client Protocol (ACP) server over JSON-RPC stdio, via the @deepseek-ai/dsh-acp-demo app — drive it from Zed or any other ACP client. It owns the ACP keyless snapshot suite.
Run with: pnpm run demo:acp (needs DEEPSEEK_API_KEY); pnpm run demo:code-mode acp boots the same server in Code Mode via the code-mode.cordis.yml overlay. See acp-agent/README.md for the Zed setup and the snapshot-test design.
The default cordis.yml composes @deepseek-ai/dsh-plan-mode, @deepseek-ai/dsh-sandbox-local, @deepseek-ai/dsh-bash-sandbox, @deepseek-ai/dsh-user-approval, and @deepseek-ai/dsh-permission. A capable client gets a default / plan mode picker plus one independent Permissions select: plan adds model guidance and the reviewed exit_plan_mode crossing without changing enforcement, while workspace-write confines bash to the configured workspace and asks before a wider retry. See acp-agent/README.md for the plan-review and elicitation flow.