GitHub Copilot Extensions @ Málaga-AI

Slides from my presentation about GitHub Copilot Extensions and other capabilities to customize Copilot behavior, such as knowledge bases, custom models and custom instructions. This presentation was done as part of Málaga-AI community activities on the 27th of March of 2025.

The code examples are available (with more to come) in this repository:
https://github.com/deors/deors-demos-github-copilot

Transcript

1. Copyright © 205 Accenture. All rights reserved. GitHub Copilot Extensions, Knowledge Bases, Custom Models & Custom Instructions
2. Copyright © 205 Accenture. All rights reserved. Software Engineering Director – Accenture Lead for our Global Java Community of Practice Lead for DevOps – Accenture Iberia CTO & Lead for Architecture & Platform Engineering – ATC EMEA South Very active in technical communities: Co-organizer MálagaJUG / BoquerónSec Co-organizer OpenSouthCode / OpenSouthKids Codemotion Ambassador Java Champion @deors.bsky.social in/deors Jorge Hidalgo
3. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** GitHub Platform a (very) fast introduction 3
4. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 4 Pull requests Projects Issues Discussions Merge queue Search CI/CD with Actions Automation Codespaces Runners CLI Advanced Security Secret scanning Security overview Supply chain Dependabot 100M+ developers Source code management Collaboration Productivity GitHub Advanced Security Biggest Developer Platform in the world Integrations & APIs Code scanning Mobile Wiki Copilot Spark Copilot Workspace
5. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** GitHub Copilot in a nutshell 5
6. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 6 LLM from GitHub specialized in assisting with Software Engineering matters CLI + IDE Chat + inline completion Multi-model Multi-file edits Extendable
7. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** How to customize GitHub Copilot 7
8. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 8 Knowledge Bases Custom Models Custom Instructions Copilot Extensions
9. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 9 Knowledge Bases • Only for Copilot Enterprise • Markdown documentation that can be used as context for Copilot chat • One or more KBs per organization • Each KB can contain documentation from one or many repositories in the organization https://docs.github.com/en/enterprise-cloud@latest/copilot/customizing-copilot/managing-copilot-knowledge-bases
10. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 10 Why? • Great for added context on specific guidance • No need to pass it in every chat request • The organization controls the content, e.g., aligned to company standards Knowledge Bases
11. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 11 • Only for Copilot Enterprise • In limited public preview • Fine-tune code completion based on code from repositories in the organization • Only one custom model per enterprise (for now) • Additional cost (if any) TBC https://docs.github.com/en/enterprise-cloud@latest/copilot/customizing-copilot/creating-a-custom-model-for-github-copilot Custom Models
12. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 12 Why? • Completions for proprietary technologies, e.g. an in-house framework • Completions for programming languages with less public source for training • Completions tailored to your coding style, standards or any other guidelines Custom Models
13. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 13 • In limited public preview • Fine-tune responses to chat requests based on the way you work, your preferences or specific guidance • They can be personal or per repository (personal goes first) • Be cautious about potential conflict between the two https://docs.github.com/en/enterprise-cloud@latest/copilot/customizing-copilot/adding-repository-custom-instructions-for-github-copilot Custom Instructions
14. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 14 Why? • Save time every time you ask for something • Consistent advice across repositories (if personal) or across team members working on a given repo (if repo-based) Custom Instructions
15. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 15 Custom Instructions We use Maven for dependency management, so when talking about dependencies and versions, always give me instructions and samples that use Maven. We prefer using properties to set dependency or plug-in versions in Maven, so always use properties to define specific versions when giving instructions and samples. We always use spaces for indentation, so when your responses include Java code, please follow that convention. .github/copilot-instructions.md for repos
16. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 16 Custom Instructions personal
17. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 17 • Integrate external services and APIs into Copilot Chat • Two flavors: Skillsets and Agents • Skillsets are lightweight, good for simple use cases • Agents are more powerful, giving you all the control over the interaction with the user https://docs.github.com/en/copilot/building-copilot-extensions/setting-up-copilot-extensions Copilot Extensions
18. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 18 Image credit GitHub: https://github.com/copilot-extensions/skillset-example/tree/main • Only ‘code’ the URL calls (skills) • GitHub analyses the prompt and decides what to call, what info to pass, and what to do with the responses • Limited to 5 skills per skillset • Full control • Code everything • Rely on external services, models, or API calls, without limitations
19. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 19 Why? • Assist to non-coding tasks • Go beyond software engineering roles • Integrate with custom (private) models • Provide support for languages or frameworks not yet supported by Copilot Copilot Extensions
20. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 20 Architecture Diagram super simple 1 2 4 3 1 2 4 3 GitHub sends the request via API call If needed, call external services (AI or not) Process response from the external services Compose and return the response to the user
21. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 21 Architecture Diagram let’s dive deeper
22. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 22
23. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 23 let’s code https://github.com/deors/deors-demos-github-copilot
24. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 24 References GitHub Documentation: https://docs.github.com/en/enterprise-cloud@latest/copilot/customizing-copilot/managing-copilot-knowledge-bases https://docs.github.com/en/enterprise-cloud@latest/copilot/customizing-copilot/creating-a-custom-model-for-github-copilot https://docs.github.com/en/enterprise-cloud@latest/copilot/customizing-copilot/adding-repository-custom-instructions-for-github-copilot https://docs.github.com/en/copilot/building-copilot-extensions/setting-up-copilot-extensions https://docs.github.com/en/copilot/building-copilot-extensions/creating-a-copilot-extension/creating-a-github-app-for-your-copilot-extension Tutorials and examples: https://github.com/copilot-extensions https://www.returngis.net/2024/12/como-crear-tu-primera-extension-para-github-copilot-chat/ https://github.com/0GiS0/tour-of-heroes-ghc-extension Working with Azure App Service and Azure AI Foundry: https://learn.microsoft.com/en-us/azure/app-service/getting-started?pivots=stack-nodejs https://learn.microsoft.com/en-us/azure/ai-foundry/what-is-ai-foundry
25. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 25 Knowledge Bases Custom Models Custom Instructions Copilot Extensions Any questions?
26. Copyright © 2025 Accenture. All rights reserved. ***Highly Confidential - Not To Be Distributed Further Without Authorization of the Sender.*** Copyright © 2025 Accenture. All rights reserved. 26 Thank you!