Introduction

When developing multi-turn conversations with DeepSeek Harness, image attachments in the conversation context often accumulate continuously: screenshots generated by tools, interfaces read by the Agent, files pasted in earlier turns, and so on. These images are re-uploaded in every step request. Measured data shows that a session carrying 13 attachments (about 14.7 MB in base64) at an upload rate of 0.07–0.10 MB/s consumes 100–140 seconds per step for this alone, easily triggering gateway timeouts (around 150 seconds).

The existing routing-level solution is to set a maxRequestImageBytes limit. But this is a byte-based “byte budget” strategy, which usually keeps only the latest images. This leads to an awkward result: the original reference images that are actually depended upon become hidden, while the most recently generated artifacts remain visible.

The dsh-image-governor plugin returns control to developers, allowing you to specify explicitly, for a single session, which images to keep and which to move out of the model’s view.

Plugin Positioning

  • Name: dsh-image-governor
  • Positioning: Session image payload governor.
  • Function: Audits the images currently carried by a session, allows manual filtering and removal of redundant images, and only changes the model’s view without deleting the actual attachments.
  • Maintainer: 2432450223
  • License: MIT

Core Features

Interactive Interface

  • Picker overlay: Provides a full-screen overlay in the bottom-right corner (shell.overlay), listing all sessions that carry images. The same panel is also registered next to the session title.
  • Operation method: When the panel opens, no images are selected by default. Checkboxes are the operation targets and support preset logic (keep newest, hide from model, select all, clear).
  • Undo mechanism: After each write change, the panel provides an undo entry.

Command-line Tool

  • View status: /images status. Displays historical image sizes, actual sent payloads, and images hidden by the limit rule.
  • Remove images: /images clear [keep <seq|name|id> …] [--newest N] [--yes].
    • Supports specifying kept items by sequence number, file name, or ID.
    • --newest N quickly keeps the N latest images.
    • Without --yes, it only previews; without arguments, it clears.
  • Restore images: /images restore [--yes]. Puts previously removed images back into the view.

Installation and Enablement

This plugin is pure JavaScript with no build steps. The installation command is as follows:

dsh plugin --profile web add github:2432450223/dsh-image-governor

Typical Usage

  1. Confirm the current image payload:
    Enter the following in the session:
    /images status

Check how many images are present and the bandwidth they occupy.
  1. Clean up unneeded images:
    If certain images are unneeded, select them and run:
    /images clear

The system displays a preview. After confirming, add `--yes` to force execution:

    /images clear --yes
  1. Restore images removed by mistake:
    If you discover an accidental removal, immediately run:
    /images restore --yes

Technical Details and Limitations

  • Implementation principle: The plugin does not modify frozen outbound requests. It uses the surface-replacing protocol allowed by the session format to append position-replacement operations ({ op: 'replace', start, end }), replacing image blocks with text placeholders. The original image events remain in the append-only log, so restore works.
  • File operations: The plugin does not delete any attachments. The attachment service itself does not provide deletion operations, and this plugin does not write to the attachment service either.
  • Execution timing: Write operations are only executed when the session is idle. While an Agent is running a turn, write requests are rejected.
  • Dependencies: Zero dependencies, pure JavaScript. It reads services via ctx.get; missing services only degrade functionality without blocking startup.
  • Permission note: This plugin runs within the DSH process permission scope. Please check the source code and license (MIT) before installing.

Conclusion

dsh-image-governor provides a refined way to manage images in the conversation context, avoiding performance degradation and context loss caused by excessive attachments. For more details and source code, refer to the project homepage.