dsh-plugin-message-edit

In a DeepSeek Harness chat, you occasionally send a prompt that needs a small tweak — a missing parameter, a reworded clause — but the only workaround is to start over in a fresh conversation and retype everything. dsh-plugin-message-edit exists for exactly that moment: it pins a tiny pencil icon next to your most recent user message, and one click forks a clean child session right before that turn, drops the original text back into the composer for inline editing, and leaves the source conversation and its old assistant reply completely untouched.

Under the hood the plugin relies on the session.fork.beforeSeq host capability. The edit action appears only on the newest committed, plain-text user message. Clicking it does not send immediately; it first completes a forked-session creation that carries no prior context, then opens the child session and locks the button against duplicate clicks. If the fork fails, the source session stays selected and a localized notice appears in the composer. Messages containing images or other non-text blocks, as well as messages in a still-running session, are shown as unavailable with a reason so that no incorrect full-history copy is ever produced.

This plugin is a good fit for researchers and engineers who iterate on prompts frequently, fix typos in flight, or want to branch a slight variation without duplicating the entire conversation context. It works in the Chat view, requires no extra dependencies, and activates as soon as the host exposes the three declared capability bits. For any DeepSeek Harness user who wants to nudge one sentence and re-run it in place, that pencil icon is the lightest solution available.