Automate marketplace.json generation from plugin directories

[Copilot]

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• My contribution adds a new instruction, prompt, agent, or skill file in the correct directory.
• The file follows the required naming convention.
• The content is clearly structured and follows the example format.
• I have tested my instructions, prompt, agent, or skill with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.

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Description

The .github/plugin/marketplace.json was out of sync with the 43 plugin directories, missing 3 plugins (context-engineering, gem-team, ospo-sponsorship). No automation existed to maintain this file.

Changes:

• Added eng/generate-marketplace.mjs - Scans plugins/*/ directories, reads .github/plugin/plugin.json metadata, generates marketplace.json
• Integrated into build - npm run build now updates both README.md and marketplace.json automatically
• Updated workflow - .github/workflows/validate-readme.yml triggers on plugins/** changes
• Documentation - Added plugin structure guidelines to AGENTS.md, script documentation to eng/README.md

Script behavior:

// Reads from each plugin's metadata file
plugins/awesome-copilot/.github/plugin/plugin.json
// Generates consolidated marketplace
.github/plugin/marketplace.json

Result: 43/43 plugins now in marketplace.json. Future plugin additions auto-sync via build process.

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Type of Contribution

• New instruction file.
• New prompt file.
• New agent file.
• New collection file.
• New skill file.
• Update to existing instruction, prompt, agent, collection or skill.
• Other (please specify): Build automation and marketplace.json generation

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Additional Notes

The marketplace.json is consumed by GitHub Copilot CLI for plugin discovery (copilot plugin marketplace add github/awesome-copilot). Manual maintenance was error-prone - this automation ensures accuracy.

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By submitting this pull request, I confirm that my contribution abides by the Code of Conduct and will be licensed under the MIT License.

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[Copilot]

Pull request overview

This PR automates the generation of .github/plugin/marketplace.json from plugin directories to eliminate manual maintenance errors. Previously, the marketplace.json file was manually maintained and was missing 3 of 43 plugins (context-engineering, gem-team, ospo-sponsorship).

Changes:

• Added automated marketplace.json generation script that scans plugin directories and extracts metadata from plugin.json files
• Integrated the generation into the build process (runs automatically with npm run build)
• Updated workflow to trigger on plugin changes and documentation to reflect the new automation

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
eng/generate-marketplace.mjs	New script that scans plugins/* directories, reads .github/plugin/plugin.json metadata, and generates consolidated marketplace.json
package.json	Integrates marketplace generation into build script and adds standalone plugin:generate-marketplace command
eng/README.md	Documents the new generate-marketplace.mjs script, its purpose, how it works, and manual invocation
AGENTS.md	Adds comprehensive plugin structure guidelines, including required fields and workflow integration
.github/workflows/validate-readme.yml	Adds plugins/** to trigger paths so workflow runs when plugin content changes
.github/plugin/marketplace.json	Generated output with 3 previously missing plugins and updated descriptions from source plugin.json files

Comments suppressed due to low confidence (2)

eng/generate-marketplace.mjs:64

• According to the guidelines in AGENTS.md (line 101), the plugin.json name field should match the folder name. The script should validate that metadata.name matches dirName and either warn or skip plugins where they don't match, to maintain consistency.

      plugins.push({
        name: metadata.name,
        source: `./plugins/${dirName}`,
        description: metadata.description,
        version: metadata.version || "1.0.0"
      });
      console.log(`✓ Added plugin: ${metadata.name}`);

eng/generate-marketplace.mjs:62

• According to the plugin structure guidelines in AGENTS.md (line 103), plugin.json must have a version field. The fallback to "1.0.0" on line 62 allows plugins without version fields to pass silently. Consider validating that the version field exists and logging a warning or error if it's missing, to enforce the documented requirement.

        version: metadata.version || "1.0.0"

[Copilot]

The script should validate that required fields (name, description) exist in the plugin.json before adding to the marketplace. Currently, if a plugin.json is missing these fields, the script will add an entry with undefined values. Consider adding validation similar to validate-collections.mjs and validate-skills.mjs, or at minimum checking that metadata.name and metadata.description are truthy before pushing to the plugins array.

This issue also appears in the following locations of the same file:

• line 58
• line 62