| name | specx-add-core-service |
| description | Add or refactor a specx core scope service. Use when implementing focused reusable business/application behavior under a core scope services package, extracting logic from a use case, injecting deterministic collaborators, accepting an active unit of work, choosing between Service and Capability, or keeping business decisions away from delivery and infrastructure. |
specx Add Core Service
Use this skill for reusable core behavior that is smaller than an application
action. Read references/service.md before writing the service.
Workflow
- Confirm this is reusable business/application behavior, not a small
replaceable ability. Use
BaseCapability instead for one narrow injectable
thing.
- Name the behavior, not a vague role, and always use the
Service suffix:
InvoicePricingService, AccessPolicyService, OrderAllocationService,
SubscriptionRenewalService.
- Put it under
core/<scope>/services/<behavior>.py.
- Choose exactly one foundation base:
BasePureService, BaseReadService, or BaseEffectService.
- Do not add or use a generic
BaseService.
- Inject concrete project collaborators when there is one implementation.
- Inject ports/ABCs only for external IO, framework-bound dependencies, or
multiple real implementations. Do not create an interface only to make a
concrete collaborator mockable.
- Add a docstring that explains the service scope and includes a concrete
Example:.
- Keep methods keyword-only after
self.
- Do not open UoW scopes in services. Use cases own transaction lifecycle and
pass active UoWs into read/effect services when needed.
- Add flat unit tests that receive the native pytest
container fixture,
register local doubles or inline mocks before resolution, and resolve the
service with container.resolve(ServiceClass).
Operational probe services may live under core/health when readiness checks
any required external dependency or policy is reused across deliveries.
Keep simple process liveness in delivery. Use a pure service for reusable
liveness policy and a read service for readiness coordination. Readiness
services depend on gateway ports, not SQLAlchemy, Redis, SDKs, or delivery
frameworks directly. Technical readiness adapters must bound external checks
with short timeouts so a probe cannot hang indefinitely.
Code Style
Use blank lines as logical separators in all code. Keep related statements
together, but separate independent setup, action, assertion, response, branch,
and transformation groups so long blocks stay readable.
References
references/service.md - class shape, dependency choices, UoW parameter
rules, and unit-test examples.
