Everything in CAP / Java
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Error handlingSAP only
Effective Axios Error Logging for Robust SAP IntegrationsEffective Axios Error Logging for Robust SAP IntegrationsTwo logged failures printed side by side, and the point is made by looking at them: one tells you what went wrong and one does not. Axios buries the useful part of an HTTP error, and this is what to unwrap before logging it from a CAP service.Sahil2508, published 2025-08-31
Messaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client ApplicationsMessaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client ApplicationsGetting a message out of a CAP service and onto a Fiori elements object page in a draft scenario — errors, warnings and information, each of which the UI treats differently. Co-written with one of the people on the OData side, and it spends its length on the message container rather than on the handler that fills it.arley-triana-morin, published 2022-08-11
Messaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client Applications
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects A recipe, Runnable code.
ODataSAP and community
#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.
Consume Remote Services in a Full-Stack CAP ApplicationConsume Remote Services in a Full-Stack CAP ApplicationExtending the Developer's Guide application with a remote S/4HANA service — connectivity, importing the Business Partner API, and running against it. SAP publishes this as four separate paths: mock server or real S/4HANA Cloud, times Cloud Foundry or Kyma. One entry covers all four, because the difference between them is which backend and which runtime, not what you learn.SAP
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.
Extend SAP SuccessFactors on SAP BTP with the SAP Cloud Application Programming ModelExtend SAP SuccessFactors on SAP BTP with the SAP Cloud Application Programming ModelTwelve tutorials, about two hours, building a side-by-side extension of SuccessFactors on BTP. The spine is remote services: importing the SuccessFactors OData service definitions into a CAP model, then treating them as entities the extension reads and writes through, rather than as an API called from a handler. Indexed as one entry because the parts only make sense in order.SAP
Messaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client ApplicationsMessaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client ApplicationsGetting a message out of a CAP service and onto a Fiori elements object page in a draft scenario — errors, warnings and information, each of which the UI treats differently. Co-written with one of the people on the OData side, and it spends its length on the message container rather than on the handler that fills it.arley-triana-morin, published 2022-08-11
Messaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client Applications
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects A recipe, Runnable code.
SAP Cloud Application Programming Model: Deep Insert (4) Consume Remote ServiceSAP Cloud Application Programming Model: Deep Insert (4) Consume Remote ServiceFourth in a long series on deep insert, and the one where the target stops being local. Twenty thousand characters, project files linked, and the earlier parts on UUIDs and multi-level structures are prerequisites the author names.CarlosRoggan, published 2019-07-24
SAP Cloud Application Programming Model: Deep Insert (4) Consume Remote Service
Destinations changed in @sap-cloud-sdk/connectivity 4.0.0, 2025-03-04. Affects A recipe, Runnable code.
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.
Serve your application over MCPSAP only
Add MCP capabilities to a CAP serviceAdd MCP capabilities to a CAP serviceA fifteen-minute walkthrough of turning a plain CAP service into an MCP server: annotate the service with @mcp, install @cap-js/mcp, and it is served alongside OData at /mcp/<path>. The part worth reading it for is what happens next — cds watch writes the endpoint into the local agent's own configuration file, so OpenCode or Claude Code can call the service without anyone editing JSON by hand. It is built on the tiny-sample facet, so there is nothing to prepare, and it shows the protocol traffic rather than only the result. Written while the adapter was in beta, and it says so.published 2026-08-13
Agentic CAP: Build MCP servers and enterprise AI agentsAgentic CAP: Build MCP servers and enterprise AI agentsCAP applications become AI agents over the Model Context Protocol and the Agent2Agent protocol, which is the serve your application over MCP concern, and SAP AI Core is the LLM integration through which AI is embedded in a CAP app, with recommendations from the SAP-RPT-1 model as the abstract's example. The abstract names the two protocols and the one model and does not say which packages carry them. A two-hour TechEd 2026 session in a hands-on room (Tuesday 27 October, Berlin), presented by Daniel Hutzel, Daniel Schlachter, Marc Huber and Sami Lechner, written here from SAP's abstract; the recording is not yet published.
CAP Node.js Expert Session #6 - The MCP AdapterCAP Node.js Expert Session #6 - The MCP AdapterDaniel Schlachter and DJ Adams add @cap-js/mcp to a bookshop service, inspect its describe, query and action tools, and query the catalogue through an AI agent. The session distinguishes this runtime adapter from the development-time MCP server and demonstrates automatic registration of the running service with a local agent. The recording describes the adapter as beta in July 2026, with read-only queries and writes through unbound actions.
Examine the details of the Model Context Protocol on startupExamine the details of the Model Context Protocol on startupWhat the MCP adapter actually does when a CAP server boots, watched rather than described — the companion to the tutorial that switches it on.
Model Context Protocol Adapter — CAP guideModel Context Protocol Adapter — CAP guideDocuments @cap-js/mcp and com.sap.cds:cds-adapter-mcp, service annotations, generated describe/query/call tools and local client setup. The guide records Java doc-comment configuration, unbound-action-based data changes, incomplete XSUAA PKCE support and the adapter’s governance boundaries.
Natural Language Queries for SAP CAP via MCP: The LLM Translates, CDS ExecutesNatural Language Queries for SAP CAP via MCP: The LLM Translates, CDS ExecutesThe division of labour is the argument, and it is in the subtitle: the model turns English into a CDS query and CDS runs it, so nothing generates SQL and nothing hallucinates a join. Schema annotations do the resolving. Long, with the package, the repository and the MCP registry entry all linked.Shahid, published 2026-06-25
The Easiest Way to Expose a CAP Node.js Project as an MCP ServerThe Easiest Way to Expose a CAP Node.js Project as an MCP ServerFrom cds init to a running MCP server in a handful of steps, ending at the MCP Inspector so the result is something you can see rather than something you have to trust. The claim it makes for the plugin is the absence of work: no REST wiring by hand, the CAP application exposed as a server because the package is installed. A walkthrough rather than an argument — the reasoning about what should be exposed lives elsewhere.Jacky Liu, published 2026-07-03
WebSocketUnmapped
Real-Time Architecture in SAP CAP: Mastering Asynchronous Jobs, Gateways with WebSocketsReal-Time Architecture in SAP CAP: Mastering Asynchronous Jobs, Gateways with WebSocketsThe other half of the author's own industrial-data post: mass ingestion is only useful if the screen keeps up, so background jobs push progress to the UI over WebSockets instead of the user reloading. Written from a mission-critical case rather than a demo.rgadirov, published 2026-03-12
Real-Time Architecture in SAP CAP: Mastering Asynchronous Jobs, Gateways with WebSockets
Async processing changed in @sap/cds 10.0, 2026-07-02. Affects A recipe.
Streaming LLM Output with CAP and WebSocketsStreaming LLM Output with CAP and WebSocketsTokens arriving from the AI SDK's orchestration module, forwarded to the browser as they come rather than after the model finishes. Covers all four pieces — enabling WebSocket support in CAP, a service with actions and events, the streaming itself, and a frontend on the native WebSocket API — which is what makes it the clearest case for why a CAP service would want a socket at all.RobinP, published 2025-11-18
Streaming LLM Output with CAP and WebSockets
LLM integration changed in @cap-js/ai 1.0.0, 2026-04-28. Affects A recipe, Runnable code.
Draft handlingSAP only
Messaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client ApplicationsMessaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client ApplicationsGetting a message out of a CAP service and onto a Fiori elements object page in a draft scenario — errors, warnings and information, each of which the UI treats differently. Co-written with one of the people on the OData side, and it spends its length on the message container rather than on the handler that fills it.arley-triana-morin, published 2022-08-11
Messaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client Applications
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects A recipe, Runnable code.
Fiori annotationsSAP only
Build and deploy a CAP Project Node.js API with a SAP Fiori Elements UI and a managed approuter configurationBuild and deploy a CAP Project Node.js API with a SAP Fiori Elements UI and a managed approuter configurationGeneration and deployment in one piece, with the managed approuter rather than a standalone one — so the routing is configuration instead of a module, and the post covers what that changes at deploy time.jlong, published 2022-02-10
Build and deploy a CAP Project Node.js API with a SAP Fiori Elements UI and a managed approuter configuration
Fiori annotations changed in @sap/cds-dk 9.6.0, 2025-12-17. Affects A recipe, Runnable code.
Build SAP Overview Page using SAP HANA Cloud & SAP CAP service annotations in Visual Studio CodeBuild SAP Overview Page using SAP HANA Cloud & SAP CAP service annotations in Visual Studio CodeAn Overview Page — the card-based Fiori elements floorplan, less written about than the list report — driven entirely from annotations on a CAP service, in VS Code rather than Business Application Studio.Sai_Nithesh_G, published 2021-08-05
Build SAP Overview Page using SAP HANA Cloud & SAP CAP service annotations in Visual Studio Code
Fiori annotations changed in @sap/cds-dk 9.6.0, 2025-12-17. Affects A recipe, Runnable code.
Building an Analytical List Page with CAP OData V4Building an Analytical List Page with CAP OData V4The annotations a CAP OData V4 service needs before an Analytical List Page will render — the write-up behind the cap-alp sample indexed here. Candid about its provenance: the author credits a GitHub repository she found the approach in, and notes that the repository is no longer available, which is the whole argument for indexing the reasoning rather than only linking the code.published 2023-06-12
Building an Analytical List Page with CAP OData V4
cap-alp: no published releases, repository quiet for 24 months. Affects A recipe, Runnable code.
CAP - Dynamically hide UI facets in Fiori ElementsCAP - Dynamically hide UI facets in Fiori ElementsFacets hidden at runtime rather than at design time, which needs two things at once: UI.Hidden on the annotation side and a virtual element on the CDS side to decide it. Both are linked from the post, and it is barely two pages.AjayRathore, published 2023-12-08
CAP - Dynamically hide UI facets in Fiori Elements
Fiori annotations changed in @sap/cds-dk 9.6.0, 2025-12-17. Affects A recipe.
CAP with Fiori Elements: Actions on List Report / Object Page using Annotations - Part1CAP with Fiori Elements: Actions on List Report / Object Page using Annotations - Part1Actions on their own, at length — where an action can be placed, what the annotation looks like for each position, and what changes between the List Report and the Object Page. Part one of two.Ajit_K_Panda, published 2023-12-31
CAP with Fiori Elements: Actions on List Report / Object Page using Annotations - Part1
Fiori annotations changed in @sap/cds-dk 9.6.0, 2025-12-17. Affects A recipe, Runnable code.
Deep Insert in SAP CAPM Using Composition and Fiori ElementsDeep Insert in SAP CAPM Using Composition and Fiori ElementsParent and children created in one transaction, which composition already gives you in the model — the post is about what Fiori elements does with it, and what the payload looks like when the UI sends both at once.published 2026-05-22
Develop a Full-Stack CAP Application Following SAP BTP Developer's GuideDevelop a Full-Stack CAP Application Following SAP BTP Developer's GuideThe eight-part path SAP's own Developer's Guide prescribes: a CAP service, Fiori Elements over it, custom logic, authorization, tests, and the preparation deployment needs. It is the closest thing to an official answer to 'what does a whole CAP application look like', which is why it sits under reference applications rather than under any one of the capabilities it touches.SAP
Developing a Fiori elements app with CAP and Fiori ToolsDeveloping a Fiori elements app with CAP and Fiori ToolsA learning write-up from someone new to CAP at the time, and long enough to be thorough. Carries its own update pointing at a newer post on deploying a CAP-based Fiori app to a central launchpad without an approuter.MioYasutake, published 2020-09-07
Developing a Fiori elements app with CAP and Fiori Tools
Fiori annotations changed in @sap/cds-dk 9.6.0, 2025-12-17. Affects A recipe, Runnable code.
Developing Fiori Element Application (List Report and Object Page) consuming the OData service created using SAP Cloud Application Programming modelDeveloping Fiori Element Application (List Report and Object Page) consuming the OData service created using SAP Cloud Application Programming modelOne of the earliest entries here, from mid-2020: the List Report and Object Page pair generated over a CAP OData service, when that combination was still new enough to need explaining.former_member187069, published 2020-06-08
Developing Fiori Element Application (List Report and Object Page) consuming the OData service created using SAP Cloud Application Programming model
Fiori annotations changed in @sap/cds-dk 9.6.0, 2025-12-17. Affects A recipe.
Developing SAP Fiori Element application by using SAP Cloud Application Programming ModelDeveloping SAP Fiori Element application by using SAP Cloud Application Programming ModelThe long version, and it starts by naming the floorplans — List Report, Worklist, Object Page, Overview Page, Analytical List Page — which is the decision most walkthroughs skip. Then one of them, built out against a CAP service.shobhit, published 2023-08-07
Developing SAP Fiori Element application by using SAP Cloud Application Programming Model
Fiori annotations changed in @sap/cds-dk 9.6.0, 2025-12-17. Affects A recipe, Runnable code.
Dynamic Criticality in SAP CAP Using Fiori Elements and Node.jsDynamic Criticality in SAP CAP Using Fiori Elements and Node.jsColouring rows by status, which sounds like a UI question and is not: criticality is a value the service has to compute and expose, so the work is a virtual element in CDS and the annotation that points at it. Comes from a real requirement — business users wanting to spot the records that need attention.Pranesh_SD, published 2026-06-05
Part 1: How to build an extension application for SAP S/4HANA Cloud using CAP, SAP Cloud SDK and SAP Fiori elementsPart 1: How to build an extension application for SAP S/4HANA Cloud using CAP, SAP Cloud SDK and SAP Fiori elementsThe substantial part of a side-by-side extensibility series: CAP Node.js, Cloud SDK and Fiori elements against S/4HANA Cloud. Eighteen thousand characters, and the one to read if you only read one.former_member748, published 2020-12-01
Part 1: How to build an extension application for SAP S/4HANA Cloud using CAP, SAP Cloud SDK and SAP Fiori elements
Fiori annotations changed in @sap/cds-dk 9.6.0, 2025-12-17. Affects A recipe, Runnable code.
Part 2: How to build an extension application for SAP S/4HANA Cloud using CAP, SAP Cloud SDK and SAP Fiori elementsPart 2: How to build an extension application for SAP S/4HANA Cloud using CAP, SAP Cloud SDK and SAP Fiori elementsThe second part, continuing the same extension. Opens with a recap of the stack rather than of the steps, which makes it readable on its own.former_member748, published 2020-12-20
Part 2: How to build an extension application for SAP S/4HANA Cloud using CAP, SAP Cloud SDK and SAP Fiori elements
Fiori annotations changed in @sap/cds-dk 9.6.0, 2025-12-17. Affects A recipe, Runnable code.
SAP CAP Remote Services & SAP Fiori ElementsSAP CAP Remote Services & SAP Fiori ElementsWhat happens to a generated UI when the data is not local: a CAP service projecting a remote one, with Fiori elements on top. The author explored it to find out where the abstraction holds, which is the useful register for this.Former Member, published 2021-05-20
SAP CAP Remote Services & SAP Fiori Elements
Fiori annotations changed in @sap/cds-dk 9.6.0, 2025-12-17. Affects A recipe, Runnable code.