runtime-change

name	runtime-change
description	Review or implement a change to runtime or platform composition, module loading and execution, auth, transport, persistence, runtime extensions, or route and module dispatch.
argument-hint	[change summary or file path]

Use this skill when a change touches the OSS runtime or platform host.

Typical triggers:

• mozaiksai/hosts/runtime.py
• mozaiksai/hosts/platform.py
• mozaiksai/core/runtime/app/module_loader.py
• mozaiksai/core/runtime/composition/module_executor.py
• mozaiksai/core/runtime/composition/module_event_router.py
• mozaiksai/core/runtime/composition/module_context.py
• mozaiksai/core/runtime/composition/platform_hooks.py
• mozaiksai/core/runtime/composition/extensions.py
• mozaiksai/core/auth/**
• mozaiksai/core/transport/**
• mozaiksai/core/runtime/persistence/**

Inspect first:

• ARCHITECTURE.md
• AGENTS.md
• CLAUDE.md
• .claude/rules/runtime.md
• .claude/rules/architecture-boundaries.md
• .claude/rules/testing.md
• docs/architecture/app/platform-authoring.md when app loading, shell, route ownership, or module dispatch changes
• docs/architecture/modules-systems/module-system.md when module contracts or module runtime composition change
• docs/architecture/foundations/events-and-data/persistence-and-artifact-storage.md when ctx.persistence, data contract, indexes, or migrations change
• factory_app/build_context/AppGenerator/file_contracts.yaml when generated app or module contracts depend on the runtime behavior
• the owning runtime file and its narrowest test slice before editing:
  • mozaiksai/hosts/runtime.py + tests/test_runtime_websocket_contract.py or tests/test_auth_oidc_discovery.py
  • mozaiksai/hosts/platform.py + tests/test_platform_ai_config_resolution.py, tests/test_platform_layout.py, or tests/test_platform_shell_p0_fixes.py
  • mozaiksai/core/runtime/app/module_loader.py + tests/test_module_loader_contracts.py
  • mozaiksai/core/runtime/composition/extensions.py + tests/test_module_runtime_extensions.py
  • mozaiksai/core/runtime/composition/module_executor.py / mozaiksai/core/runtime/composition/module_context.py + tests/test_runtime_persistence_module_injection.py
  • mozaiksai/core/runtime/composition/platform_hooks.py + tests/test_platform_hook_registry.py
  • mozaiksai/core/runtime/composition/module_event_router.py + tests/test_module_loader_contracts.py
  • generated-app dependency checks + tests/test_appgenerator_canonical_generation.py or tests/test_appgenerator_persistence_alignment.py when AppGenerator assumptions are touched

Current runtime truth:

• the runtime host is the universal substrate for auth, transport, workflow execution, persistence primitives, and event delivery
• the platform host owns app loading, module execution, module event meaning, runtime extension mounting, admin and profile discovery, and shell or route composition
• ModuleLoader validates module.yaml, companion contracts, and runtime_extensions.yaml
• ModuleExecutor builds ModuleContext, enforces action permissions and schemas, injects ctx.persistence, and emits declared events
• ModuleEventRouter is platform-owned interpretation of reactions, notifications, and capability dispatch on top of runtime event transport
• AppGenerator and generated app fixtures may depend on these contracts; inspect the file contracts and fixture tests before changing behavior

Layer boundary rules:

• Runtime = universal substrate for auth, transport, persistence primitives, workflow execution, session state, and event delivery
• Platform = app workspace loading, module registration and execution, module event meaning, app shell, admin and profile wiring, runtime extension mounting, and route or module dispatch
• Factory = build-time generation and file-contract ownership. Do not bury runtime policy in factory prompts, and do not change runtime behavior without checking generator expectations.
• Hosted = external or hosted-only product capabilities. Do not put hosted-only product logic into runtime or platform code.
• Module business logic stays in module handlers, services, and repos. Do not hardcode app-specific workflow or product rules inside runtime internals.
• mozaiksai.core.auth authenticates. Do not smuggle authorization or product policy into generic auth adapters.
• ModuleContext.persistence is ctx.persistence; do not reintroduce ctx.db.

Runtime change checklist:

1. Name the affected runtime primitive or primitives: Application, Run, ExecutionWorker, ExecutionEngine, Event.
2. Identify the smallest owning layer: runtime, platform, factory, hosted, or module code.
3. Check whether the change alters declarative contracts such as module.yaml, contracts/reactions.yaml, contracts/notifications.yaml, runtime_extensions.yaml, app.json, shell.json, or config/ai.json.
4. Check whether factory_app/build_context/AppGenerator/file_contracts.yaml or generated-app fixtures assume the current behavior.
5. Update loader or host code, docs, and tests together when a contract changes.
6. Preserve multi-tenant safety, engine-agnostic behavior, observability, runtime events, and token accounting.
7. Prefer replacement over retention shims unless the task explicitly asks to preserve an existing app surface.

Common runtime areas:

• Auth and runtime identity:
  • Inspect mozaiksai/hosts/runtime.py, mozaiksai/core/auth/**, and tests/test_auth_oidc_discovery.py.
  • Keep provider-neutral configuration and clear failure modes.
• Module loading and declarative contracts:
  • Inspect mozaiksai/core/runtime/app/module_loader.py and tests/test_module_loader_contracts.py.
  • Contract changes belong in loader validation, docs, generator file contracts, and tests together.
• Module execution and context:
  • Inspect mozaiksai/core/runtime/composition/module_executor.py, mozaiksai/core/runtime/composition/module_context.py, and tests/test_runtime_persistence_module_injection.py.
  • Keep permission and schema enforcement plus ctx.persistence injection here, not in handlers.
• Module reactions, notifications, and capability dispatch:
  • Inspect mozaiksai/core/runtime/composition/module_event_router.py and tests/test_module_loader_contracts.py.
  • The runtime carries events; the platform owns module-level meaning, notifications, and capability dispatch.
• Platform hooks:
  • Inspect mozaiksai/core/runtime/composition/platform_hooks.py and tests/test_platform_hook_registry.py.
  • Hooks are provider-neutral extension points for deployers. They must not encode hosted-only product rules in OSS.
• Runtime extensions:
  • Inspect mozaiksai/core/runtime/composition/extensions.py, mozaiksai/core/runtime/app/module_loader.py, and tests/test_module_runtime_extensions.py.
  • Keep entrypoints module-local under backend.* and contract-bound.
• Persistence, data contract, indexes, and migrations:
  • Inspect mozaiksai/core/runtime/persistence/**, tests/test_runtime_persistence_module_injection.py, and the relevant tests/test_runtime_persistence_*.py slice.
  • If generated module behavior changes, also inspect factory_app/build_context/AppGenerator/file_contracts.yaml and tests/test_appgenerator_persistence_alignment.py.
• WebSocket and session transport:
  • Inspect mozaiksai/hosts/runtime.py, mozaiksai/core/transport/websocket.py, and tests/test_runtime_websocket_contract.py.
  • Preserve resume, buffering, heartbeat, and input or resume semantics.
• Platform shell, app loading, and route or module dispatch:
  • Inspect mozaiksai/hosts/platform.py, tests/test_platform_ai_config_resolution.py, tests/test_platform_layout.py, and tests/test_platform_shell_p0_fixes.py.
  • Keep app-root resolution, app-config ownership, and shell or route loading aligned with the current platform contract.

Focused testing guidance:

• Run the narrowest area test first.
• If you changed contracts or host wiring, add the nearest generator or docs slice that depends on that behavior.
• Good starting slices:
  • module contracts and reactions: python -m pytest tests/test_module_loader_contracts.py -q
  • platform hooks: python -m pytest tests/test_platform_hook_registry.py -q
  • runtime extensions: python -m pytest tests/test_module_runtime_extensions.py -q
  • persistence injection: python -m pytest tests/test_runtime_persistence_module_injection.py -q
  • WebSocket or runtime host behavior: python -m pytest tests/test_runtime_websocket_contract.py -q
  • auth discovery or auth config: python -m pytest tests/test_auth_oidc_discovery.py -q
  • platform app loading and shell behavior: python -m pytest tests/test_platform_ai_config_resolution.py tests/test_platform_layout.py tests/test_platform_shell_p0_fixes.py -q
  • AppGenerator or runtime contract coupling: python -m pytest tests/test_appgenerator_canonical_generation.py tests/test_appgenerator_persistence_alignment.py -q
• Do not substitute a broad repo-wide run when a narrower slice can falsify the change.

Final report requirements:

• Always include Tests run.
• Always include OSS Change Impact.
• Include Module Contract Impact when module manifests, loader validation, executor behavior, or module event routing changed.
• Include Control-Plane / Refinement Impact when runtime session or control-plane resume behavior or workflow routing contracts changed.
• Include Build Workflow Sequence Impact when runtime or platform work also changes sequence or entry routing.
• Include Managed Capability Boundary Check when the change touches managed-capability boundaries, facade wiring, or adapter contracts.

Return:

1. affected runtime primitive or primitives
2. owning layer and why
3. declarative contracts or host surfaces changed
4. AppGenerator or generated-app dependency impact
5. tests required or run
6. compatibility or rollout risk