Rubber Duck Thursdays - Let's build with custom agents (again!)
Chris continues building custom agents for the SDLC, exploring the awesome-copilot repository for inspiration and live-building a GitHub Actions workflow agent with plan mode.
Topics Covered
- GitHub Changelog Roundup — Blocking repo admins from installing GitHub Apps now GA, Copilot Spaces with public spaces and code view support, secret scanning updates for November 2025, GitHub Enterprise Server 3.19 RC, assigning issues to Copilot via GraphQL and REST APIs, and Claude Opus 4.5 availability across more IDEs.
- Agent Inspiration from awesome-copilot — Reviewing partner-built agents and the awesome-copilot repository for ideas including test writers, security reviewers, tech debt analyzers, documentation generators, PR review assistants, and onboarding guides.
- Agent Consolidation — Discussing whether to keep agents separate or consolidate them based on shared tool access, output formats, and domain overlap.
- Building a GitHub Actions Agent — Using plan mode to design a custom agent for authoring and updating GitHub Actions workflows, including monorepo build order awareness and minimal permissions guidance.
- GitHub Actions Instructions File — Creating a companion instructions file with repository-specific CI/CD conventions, build order, environment variables, and recommended practices for workflow definitions.
- Plan Mode Workflow — Demonstrating the iterative plan-then-implement workflow where Copilot asks clarifying questions before generating code, and switching between plan and agent modes.
Related Content
Rubber Duck Thursdays - Let's build
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Assign issues to GitHub Copilot from the GitHub mobile app
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