Introduction

In DeepSeek Harness (DSH), a Session may still be executing tasks while another Session or Agent Team Room already requires part of the conclusions. dsh-sideband is used for asynchronous context handoff in this scenario: it performs bounded capture first, summarizes using an independent tool-free LLM call, and finally delivers according to quiet or wakeup mode.

What is this

dsh-sideband is a DeepSeek Harness plugin maintained by ishuowang, licensed under MIT. Its positioning is: Asynchronous, LLM-summarized context handoff between DeepSeek Harness sessions and agent rooms.

It is suitable for scenarios where the source Agent is still processing and you do not wish to wait or interrupt the current turn. It does not treat the full transcript as shared memory, nor does it replace the chat UI; it projects visible user text and visible model text within command boundaries and then forms a context package with provenance.

Core Features

Asynchronous Processing

The /sideband command returns a job ID after admission. Summarization and delivery continue in the background, allowing for status queries or task cancellation.

Command Boundary Capture

Capture happens at command boundaries. The plugin only projects visible user text and visible model text and excludes the following types:

  • system/developer instructions
  • plugin context
  • reasoning
  • tool calls/results
  • attachments

--focus is only used by the summarizer and will not be sent to the source model.

Independent Summarization

The plugin uses an independent tool-free LLM call to process the captured transcript. The /sideband command itself is not a prompt; it runs on DSH’s native command plane and does not enter the source model.

Delivery Modes

quiet is the default mode for a Session: it leaves the context for the target’s next turn and does not wake the target.

wakeup schedules a target turn, which may consume model quota.

Native Target Selection

The plugin uses DSH’s official popupSelect to provide native UI target selection. Entering the bare command allows selecting another regular Session in DSH Web. The full command can still be used for scope, focus, Room target, status, and cancel.

Room Delivery

dsh-sideband supports optional delivery to an Agent Team Room. The Room target requires an Agent Team Room.

Provenance

The delivery content carries information such as job, timestamp, command boundary, scope, focus, and delivery mode, facilitating target identification of the source.

Installation and Usage

Before installation, confirm the environment meets the requirements:

  • Node.js ^22.19.0 || >=24
  • DeepSeek Harness 0.1.0-rc.6

This package has not yet been published to the npm registry; the currently supported installation path is a fixed GitHub version.

dsh plugin --profile web add github:ishuowang/dsh-sideband#v0.1.0

Typical Usage

First, list current visible targets:

/sideband targets

Capture the last 16 visible messages, extract release decisions and unresolved risks, and silently deliver to another Session:

/sideband send session:<session-id> --last 16 --focus "release decisions and unresolved risks" --delivery quiet

The command returns immediately with a result similar to:

Sideband queued: sb-…

Query or cancel background tasks:

/sideband status <job-id>
/sideband cancel <job-id>

Deliver focused context to a Room:

/sideband send room:<room-id> --focus "API contract changes"

General format:

/sideband send session:<id>|room:<id> [--last N|--all] [--focus "..."] [--delivery quiet|wakeup]

Option descriptions:

  • --last N: Last N visible messages.
  • --all: All visible history.
  • --focus "...": Tells the summarizer which information to retain; will not be sent to the source model.
  • --delivery quiet: Default for Session, does not wake the target.
  • --delivery wakeup: Schedules a target turn and may consume model quota.

The compatible alias --full exists, but new scripts should use --all.

Delivery Content

The target receives a context package with provenance, which looks like this:

[Sideband recalled context]
Sideband job: sb-…
Job created: 2026-08-14T12:34:56.000Z
Delivery option: quiet
Source Session: …
Captured: 2026-08-14T12:34:56.000Z
Source command boundary: 42
Scope: last 16 visible messages
Focus: release decisions and unresolved risks

The key point here is that the delivery content carries information such as job, timestamp, command boundary, scope, focus, and delivery mode.

Suitable Scenarios and Notes

Suitable for:

  • Source session is still running, and you do not want to wait or interrupt the current turn.
  • Need to hand part of the conclusions from visible dialogue to another Session or Agent Team Room.
  • Need to retain delivery provenance to facilitate target distinction of the source.

Notes:

  • The plugin runs with the current dsh process permissions; you should check the source code and license before installing.
  • /sideband does not enter the source model.
  • --focus will not be sent to the source model.
  • wakeup mode may consume model quota.
  • Room target requires an Agent Team Room.
  • Community directory listing is for community discovery, not DeepSeek certification or endorsement.

Conclusion

The value of dsh-sideband is to deliver context that is “needed now but does not want to disturb the source session” to another DSH target in an asynchronous, summarized, and source-informative manner.

Directory: https://awesome-dsh-plugin.com/p/ishuowang/dsh-sideband/

GitHub: https://github.com/ishuowang/dsh-sideband