Claude-skill-registry add-bc-contract

Add Contract for inter-BC communication using Provider pattern. Use when one Bounded Context needs to access data from another BC (e.g., Inventory needs Articles from Admin). Creates Contract interface, Provider implementation, and configuration.

install

source · Clone the upstream repo

git clone https://github.com/majiayu000/claude-skill-registry

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/majiayu000/claude-skill-registry "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/data/add-bc-contract" ~/.claude/skills/majiayu000-claude-skill-registry-add-bc-contract && rm -rf "$T"

manifest: skills/data/add-bc-contract/SKILL.md

Add BC Contract

Create Contract for inter-BC communication using Provider pattern.

When to Use

BC needs to read data from another BC
Creating select options from another BC (TwigComponent)
Exposing domain data to other contexts

Inputs/Outputs

Input	Example	Output
provider_bc	Admin	`ProviderBC/Contracts/ContractName.php`
consumer_bc	Inventory	`ProviderBC/Adapters/Contracts/ProviderBCContractName.php`
contract_name	ArticleProvider	`ProviderBC/Frameworks/config/services.yaml` (updated)
methods	['provide', 'provideAll']	`ConsumerBC/Frameworks/deptrac.yaml` (updated)

Process

Step	File	Action
Contract	`ProviderBC/Contracts/ContractName.php`	Interface with methods (template: `contract.php.tpl` )
Provider	`ProviderBC/Adapters/Contracts/ProviderBCContractName.php`	Implementation with Finder (template: `provider.php.tpl` )
Config	`ProviderBC/Frameworks/config/services.yaml`	Autowire Contract → Provider
Deptrac	`ConsumerBC/Frameworks/deptrac.yaml`	Allow ProviderBC\Contracts
Validate	-	`make cs-fixer && make stan && bin/deptrac analyse && make qa`

Structures

Contract (interface in

ProviderBC/Contracts/

interface ContractName {
    public function provide(string $uuid): EntityData; // throws
    public function provideAll(?array $ids = null): iterable;
}

Provider (

readonly

, uses Finder):

final readonly class ProviderBCContractName implements ContractName {
    public function __construct(private EntityFinder $finder) {} // Finder, NOT Repository

    public function provide(string $uuid): EntityData {
        $entity = $this->finder->find($uuid) ?? throw EntityNotFound::fromUuid($uuid);
        return $this->toData($entity);
    }

    public function provideAll(?array $ids = null): iterable {
        $entities = $ids ? $this->finder->findByUuids($ids) : $this->finder->findAll();
        foreach ($entities as $entity) {
            yield $this->toData($entity);
        }
    }

    private function toData(Entity $entity): EntityData { /* convert to DTO */ }
}

Config (

ProviderBC/Frameworks/config/services.yaml

ProviderBC\Contracts\ContractName:
    class: ProviderBC\Adapters\Contracts\ProviderBCContractName

Deptrac (

ConsumerBC/Frameworks/deptrac.yaml

ConsumerBC\Adapters:
    - ProviderBC\Contracts  # ONLY Contracts, NOT Entities/UseCases

See:

docs/GLOSSARY.md#contract

#provider

#data-dto

Rules

CRITICAL:

Provider uses Finder (NOT Repository) - providers are read-only
Consumer depends ONLY on Contract interface (never Provider implementation)
Deptrac allows ONLY
```
Contracts
```
namespace (not Entities/UseCases)

Locations:

Contract:
```
ProviderBC/Contracts/
```
Provider:
```
ProviderBC/Adapters/Contracts/
```
Exception:
```
ProviderBC/Contracts/Exception/
```
if needed
DTO:
```
ProviderBC/Contracts/DTO/
```
if complex data

Naming:

Contract:
```
{Entity}Provider
```
(e.g., ArticleProvider)
Provider:
```
{BC}{Contract}
```
(e.g., AdminArticleProvider)

Variants

Query Provider (data access):

public function provide(string $uuid): EntityData;
public function provideAll(?array $ids = null): iterable;

TwigComponent Provider (form select):

/** @return array<string, string> [uuid => label] */
public function getAllForChoice(): array;

Templates

```
contract.php.tpl
```
- Contract interface
```
provider.php.tpl
```
- Provider implementation

Location:

.claude/templates/

References

Contract/Provider pattern:
```
docs/GLOSSARY.md#contract
```
,
```
#provider
```
Inter-BC architecture:
```
docs/architecture.md#inter-bc
```
Detailed guide:
```
docs/guides/bounded-contexts.md
```