backend-building-swarmlisted

# Backend Building Swarm **Stack**: tRPC + Drizzle ORM + Hono + MySQL + OAuth 2.0 A swarm-aware backend skill that grafts onto an existing `webapp-building-swarm` project. Adds `api/`, `contracts/`, and optionally `db/` directories — but **never replaces or modifies** existing frontend files. **Prerequisite**: An existing shared repo created by `webapp-building-swarm` at `/mnt/agents/output/app`. ## Architecture This skill builds on the **swarm-workspace** two-tier filesystem — a shared coordination repo (branch hub) plus per-subagent worktrees. See `swarm-workspace/SKILL.md` for the full contract; it is not restated here. `init.sh` grafts **in place** on `$PROJECT_PATH` and commits on whatever branch is checked out there — it does NOT manage worktrees or merge. In the swarm flow the **main agent** creates the `backend` worktree via swarm-workspace's `setup-local.sh`, runs `init.sh` in it with `PROJECT_PATH` pointed at the worktree, commits on the `backend` branch, and merges that branch into the integration line before page branches fork — so all page agents inherit the tRPC client and contracts. The main agent runs the graft itself rather than dispatching a subagent because `init.sh` writes a **gitignored** `.env` that never travels through the merge: it survives only in the sandbox where it ran, which must be the main agent's own — the one that later builds and stages `.env` into the other worktrees. Webapp commit history is preserved because the `backend` branch des