backend-launcher

# Backend Launcher > *"Same syringe, different supes. The dispatcher doesn't care who's holding it — it cares what comes back."* A reusable sub-skill (a sibling directory under `skills/`, pulled in by prose "read this file and apply"). It exposes **one contract**. The orchestrator hands a `job_spec` to whichever adapter the manifest's `backend` names, and gets back a canonical `job_result` — identical shape across every backend. Enforcement is uniform because it lives in the *caller's* scope gate, not in the backend. There is no skill-import API: an adapter is a sibling doc (`adapter-codex.md`, `adapter-claude.md`, `adapter-antigravity.md`) that says "read the contract in this file, then do the backend-specific steps." Adapters are built by downstream tasks; this file is the contract they implement. --- ## The contract ### INPUT — `job_spec` ```jsonc { "backend": "codex", // claude | codex | antigravity | cursor | devin | opencode "prompt": "…", // the worker prompt (opens with the planner/executor lock, below) "tier": "standard", // frontier | deep | standard | light — the routing INTENT (stable across model churn) "effort": "medium", // low | medium | high | xhigh — orthogonal reasoning-effort hint (optional; xhigh is codex-only) "model": "gpt-5.6-sol", // OPTIONAL explicit override; when present it skips resolution. // executio...