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SAP Cloud Application Programming Model(CAP):カスタムロジックの実装 – Part 2SAP Cloud Application Programming Model(CAP):カスタムロジックの実装 – Part 2A walkthrough of implementing custom logic in a CAP Node.js service for the capire bookshop sample, registering before, on and after handlers around the generated CRUD service for its Books and Orders entities. The before handler validates an incoming order's amount and runs a transactional CQN UPDATE to decrement stock, raising a 400 or 409 through req.error when the amount is invalid or no rows match; an after handler on READ appends a discount note to overstocked books.rasai, published 2021-01-01
CAP: GraphQL as new protocolCAP: GraphQL as new protocolWritten days after @cap-js/graphql appeared, by somebody who went looking for it — an introduction to GraphQL alongside what the adapter actually does to a CAP service. The first outside account of the capability, and still one of very few.jhodel18, published 2023-03-18
CAP: GraphQL as new protocol
@cap-js/graphql has been through 11 major lines since this was published, most recently 0.12 (2025-05), 0.13 (2025-07), 0.14 (2025-10). Affects Runnable code.
SAP CAPv7 - Node.js Highlights and ExperiencesSAP CAPv7 - Node.js Highlights and ExperiencesAn account of upgrading a 100+ table CAP Node.js project from v6 to v7, working through breaking changes in @sap/cds 7: event handlers now always receive an array, service paths move under /odata/v4/... unless serve_on_root is set, and cds-serve replaces cds run. It goes deepest on the GraphQL plugin, @cap-js/graphql: the /graphql endpoint it serves, Composition results wrapped in a nodes connection, and offset-based pagination reached through OData's top and skip rather than GraphQL's own limit and offset.published 2023-08-03
SAP GraphQL in CAPm (node.js)SAP GraphQL in CAPm (node.js)Adding the GraphQL protocol adapter to a CAP project when it was new — an entity, some data, the feature switched on, and a check that it answers. Short, and it is the earliest account here of CAP speaking something other than OData.enric101, published 2021-11-29
Importing external edmx files to your CAP project using the CDS Graphical ModelerImporting external edmx files to your CAP project using the CDS Graphical ModelerAn EDMX downloaded from the API hub — API_BUSINESS_PARTNER in the example — imported into the CDS model and its entities exposed as projections, done through the graphical modeller rather than cds import. Barely a page long.Xiao-fei_Song, published 2021-05-19
#BTP #SAPCAP: Quirky Nuggets (N03-N04)#BTP #SAPCAP: Quirky Nuggets (N03-N04)Two unrelated findings in one post, which is the format of the series: the OData operators tried against a CAP service — with a schema of deliberately awkward types to try them on — and undeploying database artifacts, which is the half people hit in anger. Numbered N03 and N04 of a run that continues either side.Ajit_K_Panda, published 2023-06-05
#BTP #SAPCAP: Quirky Nuggets (N03-N04)
Deployment changed in @sap/cds-dk 8.9.0, 2025-03-31. Affects A recipe, Runnable code.
Create a Business Service using CDS, Node.js, SQLite and a OData serviceCreate a Business Service using CDS, Node.js, SQLite and a OData serviceThe stack at its smallest — CDS, Node, SQLite, an OData service — worked through at length. Nothing cloud in it, which is the point: it is the shape of a CAP service before any of the platform arrives.raybanton, published 2021-07-12
Create a Business Service using CDS, Node.js, SQLite and a OData service
Database connectors has changed twice since this was published, most recently in @sap/cds 10.1.0, 2026-09-07. Affects A recipe, Runnable code.
Custom Functions in OData V4 – SAP Cloud Application Programming ModelCustom Functions in OData V4 – SAP Cloud Application Programming ModelFunctions rather than actions, and the distinction is where it starts: a function must return data and must never change any, so it is the read-only half of custom operations. Then how to declare and implement one on a CAP service.Roopa_N, published 2021-04-28
Custom Functions in OData V4 – SAP Cloud Application Programming Model
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects A recipe.
Dynamic OData from "any" API through SAP BTP KymaDynamic OData from "any" API through SAP BTP KymaPutting an OData face on a third-party API by way of Kyma, so the SAP side of a landscape can consume something that was never built for it. The word dynamic is doing work in the title — the shape is not modelled in advance.Gunter, published 2021-09-09
Exposing Calculation View with Dynamic Client via OData APIExposing Calculation View with Dynamic Client via OData APIGetting a HANA Cloud calculation view — built in Business Application Studio and deployed to an HDI container, which is the recommended way to build native HANA artifacts — out through an OData API. The gap it fills is the one between HANA-native development and a service a client can call, which CAP does not cover for artifacts it did not generate.published 2023-10-04
Is it time to switch to OData v4?Is it time to switch to OData v4?A recommendation with its caveat attached: use v4 on new projects, and be aware it is less mature than v2 in terms of what the SAP stack around it supports. Written after using it on a real extension project, which is what makes the caveat credible.MikeDoyle, published 2021-02-05
SAP BTP SDK for iOS & CAP with OData V4 supportSAP BTP SDK for iOS & CAP with OData V4 supportThe iOS SDK gaining OData V4, which until then made connecting a native app to a CAP service awkward — CAP defaults to v4 and the SDK did not speak it. Short, and it marks the date that stopped being a problem.KRiedelsheimer, published 2021-04-21
SAP CAP Adapter to expose OData as custom REST ServiceSAP CAP Adapter to expose OData as custom REST ServiceWalks through consuming an external OData V2 service in a CAP project — cds import converts the Northwind service's EDMX into a CSN and cds.connect.to wires up the remote proxy — then re-exposing it as plain REST with the @protocol:'rest' annotation instead of OData's own envelope. Shows two ways to reshape the response, renaming and dropping fields in a CDS projection or rewriting the returned objects in a custom service handler, and remaps ?pageSize and ?offset onto OData's $top and $skip in that same handler.Former Member, published 2021-09-15
SAP Tech Bytes: Adding Service Implementation to an SAP HANA ProjectSAP Tech Bytes: Adding Service Implementation to an SAP HANA ProjectThomas Jung converts an existing SAP HANA-only project into a CAP one, exposing its native tables, views and a calculation view as CAP service entities with @cds.persistence.exists so they get full create, update, delete and read operations without being redefined. He adds OData V2 support through an adapter proxy for callers still expecting XSODATA-shaped responses, and separately turns on CAP's OpenAPI generation with its Swagger UI test tool. A second part rebuilds the same service layer with a standalone Node.js module instead of CAP, for cases that need more control than CAP's REST or OData defaults give.published 2021-05-07
The End2End Journey: Advocates Service – CAP Service, OData V2/4 & REST in One single ProjectThe End2End Journey: Advocates Service – CAP Service, OData V2/4 & REST in One single ProjectOne CAP service exposing OData V2, OData V4 and REST at the same time, which is unusual enough to be worth the read on its own. Part of an end-to-end series, deployed on Cloud Foundry against HANA Cloud, so the protocol question sits inside a whole application rather than a snippet.KRiedelsheimer, published 2021-05-06
The End2End Journey: Advocates Service – CAP Service, OData V2/4 & REST in One single Project
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects A recipe, Runnable code.
Use Aspects, Association and Convert OData V4 to V2 using ProxyUse Aspects, Association and Convert OData V4 to V2 using ProxyTwo halves that turn out to belong together: aspects and associations in the model, and then the v4-to-v2 proxy in front of it. The model decides what the proxy has to carry, which is why the author put them in one post.rahul_rajagopal, published 2023-08-28
Edge Integration Cell : Design, deploy and manage APIsEdge Integration Cell : Design, deploy and manage APIsWalks through creating an API artifact in API Management on the customer-managed Edge Integration Cell runtime, including the option to generate the artifact by importing an OpenAPI specification rather than from a URL or by hand. It then attaches an Authentication policy and a Quota step capped at four calls per minute, deploys, and shows both the resulting 401 and the quota-breach error in the Monitor logs. The author frames it as the first of a series on Edge Integration Cell's policies.published 2023-11-15
Part 2 – Empowering SAP BTP CAP Services through Open API Spec and Annotations for Effective Communication, Collaboration and GovernancePart 2 – Empowering SAP BTP CAP Services through Open API Spec and Annotations for Effective Communication, Collaboration and GovernanceWalks through generating an OpenAPI specification for a Node.js CAP service: installing cds-swagger-ui-express, bootstrapping it in server.js, a sample CDS data model with associations and compositions, and the YUML diagram and endpoint details the Open API Preview renders in Business Application Studio. Also shows gating the Swagger UI behind a user-defined environment variable so it is served in development and QA subaccounts but excluded from the production deployment on Cloud Foundry. Second of a three-part series; the first covers the concepts and the third goes deeper into annotations.mohit_bansal3, published 2023-05-24
Part 3 – Empowering SAP BTP CAP Services through Open API Spec and Annotations for Effective Communication, Collaboration and GovernancePart 3 – Empowering SAP BTP CAP Services through Open API Spec and Annotations for Effective Communication, Collaboration and GovernanceThe closing part of a three-post series applies OData @Capabilities annotations — TopSupported, SkipSupported, CountRestrictions, UpdateRestrictions, DeleteRestrictions, FilterRestrictions, SelectSupport, SortRestrictions, SearchRestrictions, InsertRestrictions, ReadRestrictions and NavigationRestrictions — to three sample CDS entities (Purchase Order, Business Partner, Product) and shows the generated OpenAPI document changing with each one. The point it builds toward: the spec is a direct readout of the model and its annotations, not something edited by hand afterward.mohit_bansal3, published 2023-05-24
SAP Tech Bytes: Adding Service Implementation to an SAP HANA ProjectSAP Tech Bytes: Adding Service Implementation to an SAP HANA ProjectThomas Jung converts an existing SAP HANA-only project into a CAP one, exposing its native tables, views and a calculation view as CAP service entities with @cds.persistence.exists so they get full create, update, delete and read operations without being redefined. He adds OData V2 support through an adapter proxy for callers still expecting XSODATA-shaped responses, and separately turns on CAP's OpenAPI generation with its Swagger UI test tool. A second part rebuilds the same service layer with a standalone Node.js module instead of CAP, for cases that need more control than CAP's REST or OData defaults give.published 2021-05-07
Swagger UI | SAP BTP Extension Generators | Hands-on Video TutorialsSwagger UI | SAP BTP Extension Generators | Hands-on Video TutorialsA blog post wrapped around a video playlist from the SAP HANA Academy — Swagger UI for CDS, added to the BTP extension generator series. The written half is an ingredients list and a table of contents; the substance is in the recordings.dvankempen, published 2021-07-09
[Part – 2] Enrich CAP based Services with Behaviors using Annotations[Part – 2] Enrich CAP based Services with Behaviors using AnnotationsThe second half of a two-part walkthrough of CAP's behavioral annotations, following on from access control and input validation in the first part. This post works through @cds.autoexpose, @cds.api.ignore, @cds.persistence.exists/skip, @cds.on.insert/@cds.on.update and the @odata.Type/@odata.singleton mapping overrides, all shaping how a CDS model is projected into a service, which is data modelling. Alongside these it covers @cds.query.limit for default and maximum page sizes (pagination and streaming), @odata.etag with exclusive and shared locks for optimistic concurrency (concurrency control), and @cds.search for scoping $search to chosen elements (search), each with a CDS code example.published 2023-01-29
CAP WebSocketsCAP WebSocketsThe early one, from 2021, before an adapter existed to make it ordinary. Read for what the problem looked like when it had to be solved by hand.vvdries, published 2021-01-26
SAP Event Mesh: S4 HANA On-Prem and SAP CI(BTP IS) through WebSocket and WebhooksSAP Event Mesh: S4 HANA On-Prem and SAP CI(BTP IS) through WebSocket and WebhooksA step-by-step walkthrough of wiring Event Mesh to publish and consume events between an on-premise S/4HANA system and Cloud Integration, contrasting persistent queues (one subscriber, kept until consumed) against unpersisted topics, and WebSocket's AMQP transport against webhook delivery for the same queue. Two tested findings support it: a queue consumer running in continuous consumption mode receives a message ahead of a webhook on the same topic, and a message stays queued and is retried (almost 8770 times in under a minute, in the author's test) until the consumer processes it successfully.FarooqAhmed, published 2023-10-03