dsh-reactor: An Event-Driven Runtime That Makes DeepSeek Harness Agents Proactively Watch

What Does It Do?

Reactor is a DSH plugin for DeepSeek Harness that turns an on-demand agent into a proactive daemon which senses the world, evaluates real conditions, and finishes the job autonomously. It solves the classic cron problem of running on a fixed schedule without checking whether action is actually warranted. Maintained by snhna-a under the MIT license and written in TypeScript, it was last updated in 2026-09.

Core Features

• Event sources: poll HTTP endpoints, watch local files, parse shell command output, or receive events pushed from external systems via webhook.
• Condition evaluation: read values with JSONPath and combine eq/ne/gt/contains/exists/changed operators using AND/OR logic.
• Goal mode execution: inject your goal plus event context into an isolated agent session where the LLM reads files, runs commands, verifies, and fixes on its own instead of running a fixed script.
• Deterministic verification and retry: check hard signals such as file existence and command exit codes after the agent settles, then classify failures and retry transient errors once.
• Safety guards: budget gates cap daily runs and token spend, high-risk actions wait for human approval, and cooldown plus overlap protection prevent duplicate or concurrent runs.
• Run trace and continuity: every decision chain is recorded, and the previous run summary is injected into the next run so work continues where it left off.

How to Use This Plugin?

After enabling it in DSH, describe your goal in plain language, for example watching a deploy file's version field and sending a webhook alert when it changes; the agent calls reactor_define to create the rule, which then runs in the background without further input. Rules can poll a status API, watch a local file, or run a command on a schedule and analyze the output. To adjust behavior, edit the rule's event source, conditions, or execution mode. A clock-themed floating widget appears in the bottom-right of DSH Web; it can be dragged and snapped to any edge or corner, resized, and opened as a semi-transparent settings panel that surfaces trigger alerts.

How to Troubleshoot This Plugin?

If a rule does not fire as expected, first confirm the event source actually produced a change, then check that the JSONPath expressions and operators in the condition match the real data shape. When a run is blocked, it is usually hitting the budget gate, the cooldown window, or overlap protection, so relax the relevant limit and retry; actions marked high risk wait for human approval. For agent failures, inspect the failure classification in the run trace: transient errors retry automatically once, while repairable errors require you to satisfy the workspace, file, or network preconditions indicated in the message.