Introduction

The core philosophy of DeepSeek Harness (DSH) is “everything is a plugin.” Developers can extend the toolchain by writing plugins, thereby enhancing model capabilities. dsh-plugin-hello is a community-maintained minimal plugin example that demonstrates how to register a model-callable tool. This plugin is suitable as an introductory reference or as a starting point for building complex toolchains.

Plugin Overview

The plugin is maintained by user xu1132, categorized under “Model Inference,” and licensed under MIT. Its core feature is to register a tool named hello into the context when Harness is loaded. The tool accepts a required string parameter name and returns a formatted greeting.

Core Features

  • Tool registration: Registers a model-callable tool named hello.
  • Input parameter: Accepts a name parameter, which is a required string specifying the greeting target.
  • Output: Returns a formatted greeting, with the default format Hello, <name>!.
  • Configuration: Supports customizing the greeting prefix via configuration; the default prefix is Hello.

Installation and Activation

Use the official command to install the plugin into the specified profile:

dsh plugin --profile demo add github:you/dsh-plugin-hello

The dsh plugin command performs pnpm operations inside the profile directory. During installation, the plugin is automatically linked to dsh.profile.bundles, and the code in the lib/ directory is built. If you use pnpm 10+, make sure the prepare build script has been added to the allowlist; otherwise, loading will fail.

Typical Usage

After installing and starting Harness, invoke the tool in the model prompt. For example, ask the model to use the hello tool to greet a user named Ada:

Use the hello tool to greet Ada.

The model will call the tool and return Hello, Ada!.

To modify the default greeting prefix, edit the cordis.patch.yml file under the profile:

- id: hello
  name: dsh-plugin-hello
  config:
    greeting: Howdy

Notes

This plugin is suitable for developers who need to quickly verify tool registration logic. When using it, note the following:
1. Invalid configuration will cause the plugin to fail to load.
2. The plugin runs with the permissions of the current DSH process; check the source code and license before installation.

Conclusion

This is a minimal plugin implementation that covers the basic workflow of registering a tool, defining parameters, returning a formatted string, and integrating the configuration layer. Understanding its source code helps master the plugin development conventions of DeepSeek Harness. For more details, see the GitHub repository.