The per-tenant DSLContext routing recipe is being rewritten under R45 alongside the tenant-column work. Until R45 ships, single-tenant apps pass a single DSLContext to Graphitron.newExecutionInput(dsl, …); multi-tenant routing through the generated byTenant factory overload, the @tenantId argument directive, and per-tenant DataLoader partitioning all land together under R45.
For the single-tenant request-entry shape, see the tutorial and Runtime API reference.