# Specx Add Core Service

> 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.

- **Type:** Skill
- **Install:** `agentstack add skill-maksimzayats-specx-specx-add-core-service`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [maksimzayats](https://agentstack.voostack.com/s/maksimzayats)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [maksimzayats](https://github.com/maksimzayats)
- **Source:** https://github.com/maksimzayats/specx/tree/main/skills/specx-add-core-service
- **Website:** https://specx.dev

## Install

```sh
agentstack add skill-maksimzayats-specx-specx-add-core-service
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# 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

1. Confirm this is reusable business/application behavior, not a small
   replaceable ability. Use `BaseCapability` instead for one narrow injectable
   thing.
2. Name the behavior, not a vague role, and always use the `Service` suffix:
   `InvoicePricingService`, `AccessPolicyService`, `OrderAllocationService`,
   `SubscriptionRenewalService`.
3. Put it under `core//services/.py`.
4. Choose exactly one foundation base:
   `BasePureService`, `BaseReadService`, or `BaseEffectService`.
5. Do not add or use a generic `BaseService`.
6. Inject concrete project collaborators when there is one implementation.
7. 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.
8. Add a docstring that explains the service scope and includes a concrete
   `Example:`.
9. Keep methods keyword-only after `self`.
10. Do not open UoW scopes in services. Use cases own transaction lifecycle and
   pass active UoWs into read/effect services when needed.
11. 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.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [maksimzayats](https://github.com/maksimzayats)
- **Source:** [maksimzayats/specx](https://github.com/maksimzayats/specx)
- **License:** MIT
- **Homepage:** https://specx.dev

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-maksimzayats-specx-specx-add-core-service
- Seller: https://agentstack.voostack.com/s/maksimzayats
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.