# Vtex Io Service Apps

> Apply when building backend service apps under node/ in a VTEX IO project or configuring service.…

Apply when building backend service apps under node/ in a VTEX IO project or configuring service.json routes. Covers the Service class, middleware functions, ctx.clients pattern, JanusClient, ExternalClient, MasterDataClient, and IOClients registration. Use for implementing backend APIs, event handlers, or integrations that must use @vtex/api clients instead of raw HTTP libraries.

- Page: https://ss33.ai/skills/vtex/vtex-io-service-apps-55959309194
- Publisher: vtex
- Category: [Software Development](https://ss33.ai/skills/category/software-development-t44z8z) › [APIs & backend](https://ss33.ai/skills/category/software-development-t44z8z/apis-and-backend-t0x840)
- Source: https://github.com/vtex/skills/blob/4d64850af3dc09e258591bf43bc0b79119242d8a/exports/opencode/vtex-io-service-apps/SKILL.md

## Skill

This skill's licence does not allow redistribution, so the store does not serve its text. Get it from the author: https://github.com/vtex/skills/blob/4d64850af3dc09e258591bf43bc0b79119242d8a/exports/opencode/vtex-io-service-apps/SKILL.md