🫤 Guidance on how to use Copilot Coding Agents with Poly Repo structure ❓

[michael-proctor]

🏷️ Discussion Type

Question

💬 Feature/Topic Area

Copilot Coding Agent

Body

Have been trialling Github Coding Agents in our organization. One of the challenges we are facing is the poly repo structure. Each library, service is it's own repository. When doing a feature which requires changes across boundaries it becomes painful to link up the work from each agent.

Although I understand the core principle of the sandboxed environment only having access to the targeted repository, is there anyway we can provide rules to give it access to other repositories so it can have complete context?

We have a legacy codebase which is a distributed monolith in a mono repo pattern, Copilot does great at seeing the context across the boundaries and makes the required changes across the multiple projects.

Is there any guidance on how to operate in a poly repo pattern with Coding Agent?

[michael-proctor]

I haven't tried but did consider trying to do a checkout of the other repositories in the copilot-setup-steps, but this is messy and also comes with challenges of it correctly creating new branches on the "associated" repos along with creation of PRs etc. (I'm not sure if it can even do a git clone), although found you can instruct the agent to change git config :D

Is there anything in the roadmap to address this by chance?

[WilliamRossCrane]

Currently, Copilot Coding Agents are sandboxed to a single repository, so they don’t natively handle cross-repo changes in a polyrepo setup.

Some workarounds include:

• Cloning other repos locally so the agent can read them, though managing branches and PRs across multiple repos can get tricky.
• Providing relevant snippets from other repos in the agent’s prompt, which works for small dependencies but doesn’t scale.
• Custom scripts to automate cross-repo PRs while letting the agent operate within each repo individually.

At the moment, full polyrepo support isn’t officially available, so the best practice is to treat the agent as repo-specific and coordinate multi-repo changes manually or with tooling.

Mark as answered if your happy with this :D

[Citrate-0358]

Gemini said
Use a multi-root workspace in VS Code to give the agent simultaneous local context across all your repositories for cross-repo edits.

Maintain a shared schema or .github/copilot-instructions.md in each repo to explicitly define the contracts and paths of its dependencies.

[hsinhan-h]

Hi @michael-proctor , this is a very common pain point and it also bothered me quite a bit when I first started using Copilot in a poly repo setup too. Here are my key takeaways after working throughcross-repo devlopment in my organization:

1. Use VS Code as your IDE :
   Go to File -> Add Folder to Workspace to add all the relevant repositories into a single workspace.

2. Pin the files you needed as context:
   Navigate to the files across repos that are relevant to your feature, then right-click: and select "Add File to chat"
3. Let Copilot agent mode do the heavy lifting!
   Agent Mode can explore across all of them and make coordinated edits spanning multiple repositories simultaneously.

This gives Copilot a unified view across your repositories without needing to change your actual repo structure. Hope this helps!

[michael-proctor]

Appreciate the reply, I am aware locally you can do this, however, this is actually about using the cloud agents, we are trialling the Jira copilot integration.

In this case the issue is assigned to Copilot which a job running spins up an environment and copilot operates in there. The issue is this environment is sandboxed to a single repo.

Was hoping someone in GitHub might give some insight as a poly repo pattern is a very common pattern, and also in normal agile practice it is normal to vertical slice which would mean needing access to multiple repositories for context.

Otherwise you need to get very granular with horizontal slicing to cover each piece of work separately without copilot being able to get a clear end to end view of the work.

We have used it in a mono repo codebase and it worked well, but poly repo is challenging.

[Kunal-Prime]

Hi @michael-proctor 👋

Copilot Coding Agents are repo-scoped by default, but you can make them work great with polyrepo setups. Here’s the practical way:

Best working setup right now:

1. Per-repo agent instructions

   • In every repo create .github/copilot-instructions.md
   • Put your architecture rules, coding style, tech stack, etc. inside it. The agent reads this automatically.

2. Cross-repo context tricks

   • In VS Code Copilot Chat, paste relevant files/code from the other repos when needed.
   • Use @workspace + manual context for quick switches.
   • For bigger projects, many people temporarily open the most relevant repos together in a multi-root workspace.

3. Stronger option (recommended)

   • Consider Turborepo or Nx to turn your polyrepo into a monorepo-like experience. Copilot then gets full context across packages while you still keep separate git repos if you want.

4. Advanced

   • You can create custom Copilot Agents (via GitHub settings) and give them specific instructions for each service.

Would love to help more — can you tell me:

• How many repos?
• What stack (Next.js, Node, Python, etc.)?
• What exactly the agents are struggling with?