Automating cross-repo documentation with GitHub Agentic Workflows

“Where are the docs?” It’s a question nobody on a product team enjoys answering. The honest reply is usually some variant of “behind.” A writer is staring at a closed pull request, trying to reverse-engineer what changed. The pull request’s author has already moved on. By the time the doc actually publishes, the feature has shipped, sometimes more than once. That used to be us on the Aspire team (we’re a small team of 10 building dev tools for distributed apps). A few months back, we were trying to figure out how to safely bring AI into automations we already trusted. That’s when we discovered GitHub Agentic Workflows. I started bolting prototypes into microsoft/aspire . Here’s what that bought us, in numbers pulled straight out of GitHub: for Aspire 13.3 and 13.4, 82 feature-docs pull requests merged at a median of 44.8 hours after the product pull request , every one of them reviewed by the engineer who shipped the feature. No new headcount. No process retraining. Just a different way of asking “who writes this?” 🔒 The constraint: cross-repo automation is the hard part Our product lives in microsoft/aspire and our docs site lives in microsoft/aspire.dev —different repo, deploy target, and review chain. Most teams figure out same-repo automation pretty quickly; cross-repo automation is where things get sharp. Broad repo-scoped tokens belong in a museum, and any responsible security posture (ours included) restricts them accordingly. That’s a good thing. It’s also a real bottleneck if the place where you write the docs isn’t the place where you write the code. The default workflow for years was: Engineer ships a feature in microsoft/aspire . Docs writer notices weeks later. Docs writer opens the pull request, reads the diff, and pings the engineer to clarify what changed. Engineer is on the next feature, vaguely remembers, replies with half the picture. Docs draft ships, sometimes against a release that’s already out. This is the reverse-engineering tax. We needed a