A DeepSeek Harness (DSH) plugin that injects the api-designer skill into the system prompt, providing comprehensive guidance for designing clean, consistent REST and GraphQL APIs.

Features

Injects the api-designer skill content into the system-prompt persona (order 10, after deployment persona).
Covers resource modeling, URI design, HTTP semantics, versioning, pagination, filtering/sorting, error contracts (RFC 9457), idempotency, concurrency control, authentication, rate limiting, and machine-readable contracts (OpenAPI 3.1 / GraphQL SDL).
Helps agents when designing new APIs, reviewing API designs, choosing REST vs GraphQL, defining error responses, or writing OpenAPI/GraphQL schemas.

Installation

Prerequisites

DeepSeek Harness dsh installed and configured.
Web profile installed (default: ~/.dsh/profiles/web/).

Option A: Using `dsh plugin add` (recommended)

dsh plugin --profile web add github:your-username/dsh-api-designer

Then add the plugin to your profile's package.json bundles list (see Option B for example).

Option B: Manual installation

Clone or download this repository into your DSH plugins directory:

cd ~/.dsh/plugins
git clone https://github.com/your-username/dsh-api-designer.git

Edit your web profile's package.json (typically ~/.dsh/profiles/web/package.json) to include the plugin in the dsh.profile.bundles array and as a dependency:

{
  "dsh": {
    "profile": {
      "bundles": [
        "@deepseek-ai/dsh-base",
        "@deepseek-ai/dsh-web-app",
        "dsh-api-designer"
      ]
    }
  },
  "dependencies": {
    "dsh-api-designer": "file:../../plugins/dsh-api-designer"
  }
}

Install dependencies:

cd ~/.dsh/profiles/web
pnpm install

Restart the DSH web server:

dsh web

Hard-refresh your browser to load the new plugin.

Usage

Once installed, the api-designer skill is automatically injected into the system prompt for all agents. The agent will have access to API design best practices when:

Designing new REST or GraphQL APIs
Reviewing existing API designs
Deciding between REST, GraphQL, or RPC
Choosing versioning or pagination strategies
Defining error responses (RFC 9457 Problem Details)
Adding idempotency keys or concurrency control
Writing or critiquing OpenAPI 3.1 or GraphQL SDL schemas
Establishing API style guidelines

No configuration is required; the skill is always active.

How It Works

The plugin registers a system-prompt section with order 10 (after the deployment persona at order 0, but before tool guidance at orders 100–199). The section content is extracted from skill.md (YAML frontmatter stripped) and injected into every prompt assembly.