Overview
You can wrap Claude Code in a GitHub Action and trigger it on issues or PR comments. It works — but it’s a starting point, not a finished product. Twill builds the workflow layer that a raw GitHub Action can’t provide.Key Differences
| Capability | DIY GitHub Action | Twill |
|---|---|---|
| Interactivity | One-shot, fire-and-forget | Both sync and async — chat to brainstorm a plan, steer the agent mid-run, or let it run in the background for long tasks |
| Human-in-the-loop | Retry or re-trigger manually | Review plans, edit specs, approve steps before code is written |
| Run duration | Capped by GitHub Actions timeout | Long-running agents with persistent state |
| Environment | Runs in CI runner | Isolated sandbox with devcontainer support and live previews |
| Visibility | Logs buried in Actions tab | Real-time agent logs, screenshots, and proof-of-work in every PR |
| Multi-model | Single agent, single model | Route tasks to Claude Code, Codex, or OpenCode — each in its native harness |
| Integrations | Build it yourself | Slack, Linear, Notion, GitHub Issues out of the box |
| Live Previews | No built-in preview support | Every PR includes a live preview URL so you can see changes before merging |
| Onboarding | Manual prompt engineering | Auto-onboarding reads your repo and generates context for the agent |
When a GitHub Action Is Enough
A DIY GitHub Action can work well for:- Simple, well-scoped automations (label-based triage, auto-formatting)
- Teams comfortable maintaining CI scripts and prompt templates
- One-off prototyping to evaluate coding agents
When You Outgrow It
Teams typically hit limits when they need:- Collaboration — Multiple people steering or reviewing agent work in Slack or a shared UI
- Reliability — Persistent state, retries, and environments that don’t vanish after a run
- UX — Plan approval, brainstorming, follow-up messages, and back-and-forth with the agent — not just a comment box in a GitHub issue
- Scale — Dedicated sandboxed environments for each task, so you can run many agents in parallel without queuing behind CI jobs or burning through Actions minutes