Add agent-harness topic

[ar27111994]

Please confirm this pull request meets the following requirements:

• I followed the contributing guidelines: https://github.com/github/explore/blob/main/CONTRIBUTING.md.
• This change is not self-promotion.

Which change are you proposing?

• Suggesting edits to an existing topic or collection
• Curating a new topic or collection
• Something that does not neatly fit into the binary options above

---

Editing an existing topic or collection

I'm suggesting these edits to an existing topic or collection:

• Image (and my file is *.png, square, dimensions 288x288, size <= 75 kB)
• Content (and my changes are in index.md)

N/A

Curating a new topic or collection

• I've formatted my changes as a new folder directory, named for the topic or collection as it appears in the URL on GitHub (e.g. https://github.com/topics/[NAME] or https://github.com/collections/[NAME])
• My folder contains a *.png image (if applicable) and index.md
• All required fields in my index.md conform to the Style Guide and API docs: https://github.com/github/explore/tree/main/docs

This curates the existing agent-harness topic, which is already used by public repositories for AI agent runtime scaffolding, coding-agent harnesses, and harness-engineering resources. The topic page currently lacks a description, so this adds neutral, community-oriented metadata and body text explaining the general concept without naming or promoting a specific project.

Something that does not neatly fit into the binary options above

• My suggested edits are not about an existing topic or collection, or at least not a single one
• My suggested edits are not about curating a new topic or collection, or at least not a single one
• My suggested edits conform to the Style Guide and API docs: https://github.com/github/explore/tree/main/docs

N/A

[github-actions]

Maintainer triage

Topics

• agent-harness — 186 repositories — topic page

[Copilot]

Pull request overview

This pull request curates the agent-harness topic by adding a new topic page (index.md) with YAML front matter metadata and a short body description explaining what agent harnesses are.

Changes:

• Added a new topic definition for agent-harness (display name, aliases, related topics, short description).
• Added a longer topic body describing typical components and use cases of agent harnesses.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.