API Reference

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Overview

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Core API

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contract-kit (meta package)

• createContractGroup(), createClient(), createUseCaseFactory(), definePorts()
• Re-exports core, client, application, domain, ports, errors, config, and OpenAPI helpers

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@contract-kit/core

• createContractGroup() - Create a group of related contracts
• Contract builders - .get(), .post(), .put(), .patch(), .delete()
• Schema methods - .path(), .query(), .body(), .response(), .errors()
• Metadata methods - .meta(), plus OpenAPI helpers like .summary() and .tags()

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@contract-kit/server

• createServer() - Create a framework-agnostic server
• Middleware - Request pipeline and middleware support
• Context - Request-scoped context creation
• Error handling - Global and route-level error handlers

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@contract-kit/client

• createClient() - Create a typed HTTP client
• Request methods - Type-safe API calls
• Response handling - Typed response handling
• Configuration - Global and per-request options

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Server Adapters

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@contract-kit/next

• createNextServer() - Next.js server initialization
• Route handlers - App Router and Pages Router support
• Configuration - Next.js adapter options

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Architecture APIs

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@contract-kit/application

• createUseCaseFactory() - Create a typed use case factory
• useCase.command() / useCase.query() - Define use cases
• run() - Execute a use case
• Validation - Input/output validation

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@contract-kit/ports

• definePorts() - Define application ports
• Provider registration - Register provider implementations
• Type safety - Fully typed dependency injection

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React APIs

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@contract-kit/react-query

• createRQ() - Create the React Query adapter
• rq(contract).queryOptions() - Typed query options
• rq(contract).mutationOptions() - Typed mutation options
• Configuration - Query client setup

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@contract-kit/react-hook-form

• rhf(contract) - Create a React Hook Form adapter
• useForm() - Form hook with validation
• Schema integration - Standard Schema resolver generation

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Provider APIs

• create[Provider]Provider() - Factory function
• Configuration options - Provider-specific config
• Port interface - TypeScript interface for the port

• @contract-kit/provider-redis
• @contract-kit/provider-drizzle-turso
• @contract-kit/provider-mail-resend
• @contract-kit/provider-mail-smtp
• @contract-kit/provider-auth-better-auth
• @contract-kit/provider-inngest
• @contract-kit/provider-rate-limit-upstash

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Utility APIs

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@contract-kit/openapi

• contractsToOpenAPI() - Generate OpenAPI 3.1 spec
• Configuration - OpenAPI generation options
• Customization - Extend generated spec

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Type Utilities

import type { InferInput, InferOutput, HttpContractConfig } from "@contract-kit/core";
import type { InferPath, InferQuery, InferBody } from "@contract-kit/server";
import type {
  InferSuccessResponse,
  InferPathParams,
  InferQuery as InferClientQuery,
  InferBody as InferClientBody,
} from "@contract-kit/client";

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Next Steps