Backend Service Apps & API Clients

When this skill applies

Use this skill when developing a VTEX IO app that needs backend logic — REST API routes, GraphQL resolvers, event handlers, scheduled tasks, or integrations with VTEX Commerce APIs and external services.

• Building the Service entry point (node/index.ts) with typed context, clients, and state
• Creating and registering custom clients extending JanusClient or ExternalClient
• Using ctx.clients to access clients with built-in caching, retry, and metrics
• Configuring routes and middleware chains in service.json

Do not use this skill for:

• Manifest and builder configuration (use vtex-io-app-structure instead)
• GraphQL schema definitions (use vtex-io-graphql-api instead)
• React component development (use vtex-io-react-apps instead)

Decision rules