vtex-io-session-apps
VTEX IO session transform apps
When this skill applies
Use this skill when your VTEX IO app integrates with the VTEX session system (vtex.session) to derive, compute, or propagate state that downstream transforms, the storefront, or checkout depend on.
- Building a session transform that computes custom fields from upstream session state (e.g. pricing context from an external backend, regionalization from org data)
- Declaring input/output fields in
vtex.session/configuration.json - Deciding which namespace your app should own and which it should read from
- Propagating values into
public.*inputs so native transforms (profile, search, checkout) re-run - Debugging stale session fields, race conditions, or namespace collisions between apps
- Designing B2B session flows where
storefront-permissions, custom transforms, and checkout interact
Do not use this skill for:
- General IO backend patterns (use
vtex-io-service-apps) - Performance patterns outside session transforms (use
vtex-io-application-performance) - GraphQL schema or resolver design (use
vtex-io-graphql-api)
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257vtex-io-application-performance
Apply when improving VTEX IO Node or .NET services for latency, throughput, and resilience: in-process LRU, VBase, stale-while-revalidate, AppSettings loading, request context, parallel client calls, and avoiding duplicate work. Covers application-level performance patterns that complement edge/CDN caching. Use when optimizing backends beyond route-level Cache-Control.
256vtex-io-service-apps
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.
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