Development
15. Development — Hermes as a Hands-On Coding Assistant
This is the area where most of the tools described in chapter 8 (Terminal, File Reading/Writing) and chapter 11 (GitHub via the gh CLI) come together into a complete software development workflow. The difference from an ordinary coding copilot: Hermes does not just suggest code inside the IDE — it can run commands itself, test itself, commit itself, open PRs itself, and most importantly, run multiple sessions in parallel on the same repo without colliding with each other.
The underlying mechanism: Git Worktree — running multiple agents in parallel, safely
This is the most important technical point to understand before diving into each sub-section. Hermes comes with a -w flag that automatically creates a throwaway worktree with its own branch:
hermes -w # interactive session inside a worktree
hermes -w -q "Fix issue #123" # single query inside a worktree
Every CLI session with worktree: true enabled creates a new worktree under .worktrees/ with its own branch — the agent can modify files, commit, push, and open PRs without interfering with other sessions running in parallel on the same repo. By default, a new worktree branches from the most recently fetched remote tip (not the local HEAD, which may already be stale) — this keeps the PR diff reflecting only the actual changes, without inheriting discrepancies caused by a lagging local clone.
Checkpoints and /rollback — a safety net for changes made along the way
Besides git commit (used for major milestones), Hermes has its own per-worktree checkpoint mechanism — use /rollback as a safety net for small fixes made by tools, independently of the official git history.
The six sub-sections follow the lifecycle of a code change
- Repository Inspection (15.1) — understand the codebase before touching it.
- Feature Creation (15.2) — writing new features.
- Bug Fixes (15.3) — fixing bugs methodically.
- Tests and Lint (15.4) — confirming that changes are correct and clean.
- Pull Requests (15.5) — putting changes up for review.
- Code Review (15.6) — both self-review and reviewing other people’s code.