dsh-preset-run

In DeepSeek Harness, the Web frontend can open a new session, pick an agent preset, and send a message — but that pipeline has never been exposed as a programmatic entry point. If you want to let another preset-driven agent run a sub-task inside your current conversation and hand back the result, you used to have to open a manual window or wire up low-level APIs yourself. dsh-preset-run closes that gap: it registers a preset_run(preset, task) host-plane tool so a single call completes the full cycle of creating an isolated session, mounting the chosen preset, executing the task, and returning the final text — all through the official agentPresets.mount path, identical to the Web backend's composeAgent implementation.

Each sub-session is ephemeral: once it finishes, the agent is disposed, the session is removed from the registry, and no UI artifacts remain. The preset list is not hard-coded; whatever is present in the deployed agentPresets roster is available out of the box — the built-in standard, code, minimal, and cordis presets work immediately, and third-party routing presets appear automatically once installed. Model routing, timeout handling, and error cleanup are all built in, so callers only need to specify which preset to use and what task to run.

This plugin is ideal for agent workflows that require cross-preset collaboration: for example, probing with a router-spec preset that narrows tools on the first turn, then executing a full task under the standard preset; or debugging the cordis preset without interrupting your current session. Multi-step orchestration, parallel sub-task dispatch, and agent-to-agent relay are all natural fits.