# Backend Loop Engineering Epic 0: Control Plane Inventory Epic 0 makes every runnable backend surface visible before changing harness behavior. It is intentionally backend-first and keeps dashboard UI work out of scope. ## Goal Create a reliable control-plane inventory for SDLC-rstack so future harness, validator, retry, memory, and checkpoint work starts from known runtime surfaces instead of assumptions. ## Scope Epic 0 covers: - Package agents under `agents/**/*.md`. - Package skills under `skills/**/SKILL.md`. - Package plugins under `plugins/*/plugin.json`. - Plugin-provided agents and command prompts. - Package prompts under `prompts/*.md`. - Pi extension tools, hooks, and commands from `src/integrations/pi/rstack-sdlc.ts`. - CLI commands from `bin/rstack-agents.js`. - Project-local RStack assets under `.rstack/` when present. Epic 0 does not change pipeline execution semantics, retry policy, validator behavior, approval rules, memory trust, checkpoints, or the dashboard. ## Issue Map | Issue | Purpose | Expected output | | --- | --- | --- | | #109 | Epic tracker for Backend Control Plane Inventory | This coordination doc and PR tracking | | #110 | Inventory Pi tools, CLI commands, hooks, agents, skills, plugins, prompts | `rstack-agents inventory` and `.rstack/registry/backend-inventory.json` | | #111 | Document runtime differences: Pi vs Claude Code vs CLI | Runtime invocation docs for agents, skills, plugins, hooks, tools, and commands | ## Acceptance Checklist - The package can generate a registry report without running the dashboard. - The registry report includes counts, kind, source path, domain, command name, and runtime availability. - Backend docs explain the invocation difference between Pi native tools, Claude Code portable assets, and framework-neutral CLI commands. - The docs clearly state that Pi has hook-based tool-call gating while Claude Code portable assets do not. - External projects are used only as implementation references. SDLC-rstack code remains original and uses existing MIT-licensed harness primitives. ## Next Epics After Epic 0, backend loop engineering should proceed in this order: 1. Harness State Spine: regenerate pipeline state from existing run artifacts. 2. Builder/Validator Contracts: make every unit of work machine-checkable. 3. Retry and Recovery Loop: deterministic bounded retry from validation results. 4. Goal Loop: stop only when declared success criteria pass or human input is required. 5. Guardrails, Approvals, Checkpoints: make safety enforceable in backend state. 6. Cost, Context, Memory: keep loop runs bounded and auditable.