SAP CAP-Capire Development Skill

Related Skills

• sap-fiori-tools: Use for UI layer development, Fiori Elements integration, and frontend application generation
• sapui5: Use for custom UI development, advanced UI patterns, and freestyle application building
• sap-btp-cloud-platform: Use for deployment options, Cloud Foundry/Kyma configuration, and BTP service integration
• sap-hana-cli: Use for database management, schema inspection, and HDI container administration
• sap-abap: Use for ABAP system integration, external service consumption, and SAP extensions
• sap-btp-best-practices: Use for production deployment patterns and architectural guidance
• sap-ai-core: Use when adding AI capabilities to CAP applications or integrating with SAP AI services
• sap-api-style: Use when documenting CAP OData services or following API documentation standards

Table of Contents

• Quick Start
• Project Structure
• Core Concepts
• Database Setup
• Deployment
• Bundled Resources

Quick Start

Project Initialization

# Install CAP development kit
npm i -g @sap/cds-dk

# Create new project
cds init <project-name>
cds init <project-name> --add sample,hana

# Start development server with live reload
cds watch

# Add capabilities
cds add hana          # SAP HANA database
cds add sqlite        # SQLite for development
cds add xsuaa         # Authentication
cds add mta           # Cloud Foundry deployment
cds add multitenancy  # SaaS multitenancy
cds add typescript    # TypeScript support

Basic Entity Example

using { cuid, managed } from '@sap/cds/common';

namespace my.bookshop;

entity Books : cuid, managed {
  title       : String(111) not null;
  author      : Association to Authors;
  stock       : Integer;
  price       : Decimal(9,2);
}

entity Authors : cuid, managed {
  name        : String(111);
  books       : Association to many Books on books.author = $self;
}

Basic Service

using { my.bookshop as my } from '../db/schema';

service CatalogService @(path: '/browse') {
  @readonly entity Books as projection on my.Books;
  @readonly entity Authors as projection on my.Authors;
  
  @requires: 'authenticated-user'
  action submitOrder(book: Books:ID, quantity: Integer) returns String;
}

MCP Integration

This skill integrates with the official CAP MCP (Model Context Protocol) server, providing AI agents with live access to your project's compiled CDS model and CAP documentation.

Available MCP Tools:

• search_model - Fuzzy search for CDS entities, services, actions, and relationships in your compiled CSN model
• search_docs - Semantic search through CAP documentation for syntax, patterns, and best practices

Key Benefits:

• Instant Model Discovery: Query your project's entities, associations, and services without reading files
• Context-Aware Documentation: Find relevant CAP documentation based on semantic similarity, not keywords
• Zero Configuration: No credentials or environment variables required
• Offline-Capable: All searches are local (model) or cached (docs)

Setup: See MCP Integration Guide for configuration with Claude Code, opencode, or GitHub Copilot.

Use Cases: See MCP Use Cases for real-world examples with quantified ROI (~$131K/developer/year time savings).

Agent Integration: The specialized agents (cap-cds-modeler, cap-service-developer, cap-project-architect, cap-performance-debugger) automatically use these MCP tools as part of their workflows.

Project Structure

project/
├── app/              # UI content (Fiori, UI5)
├── srv/              # Service definitions (.cds, .js/.ts)
├── db/               # Data models and schema
│   ├── schema.cds    # Entity definitions
│   └── data/         # CSV seed data
├── package.json      # Dependencies and CDS config
└── .cdsrc.json       # CDS configuration (optional)

Core Concepts

CDS Built-in Types

Common Aspects

using { cuid, managed, temporal } from '@sap/cds/common';
// cuid = UUID key
// managed = createdAt, createdBy, modifiedAt, modifiedBy
// temporal = validFrom, validTo

Event Handlers (Node.js)

// srv/cat-service.js
module.exports = class CatalogService extends cds.ApplicationService {
  init() {
    const { Books } = this.entities;
    
    // Before handlers - validation
    this.before('CREATE', Books, req => {
      if (!req.data.title) req.error(400, 'Title required');
    });
    
    // On handlers - custom logic
    this.on('submitOrder', async req => {
      const { book, quantity } = req.data;
      // Custom business logic
      return { success: true };
    });
    
    return super.init();
  }
}

Basic CQL Queries

const { Books } = cds.entities;

// SELECT with conditions
const books = await SELECT.from(Books)
  .where({ stock: { '>': 0 } })
  .orderBy('title');

// INSERT
await INSERT.into(Books)
  .entries({ title: 'New Book', stock: 10 });

// UPDATE
await UPDATE(Books, bookId)
  .set({ stock: { '-=': 1 } });

Database Setup

Development (SQLite)

// package.json
{
  "cds": {
    "requires": {
      "db": {
        "[development]": { 
          "kind": "sqlite", 
          "credentials": { "url": ":memory:" } 
        },
        "[production]": { "kind": "hana" }
      }
    }
  }
}

Production (SAP HANA)

cds add hana
cds deploy --to hana

Initial Data (CSV)

• File location: db/data/my.bookshop-Books.csv
• Format: <namespace>-<EntityName>.csv
• Auto-loaded on deployment

Deployment

Cloud Foundry

# Add CF deployment support
cds add hana,xsuaa,mta,approuter

# Build and deploy
npm install --package-lock-only
mbt build
cf deploy mta_archives/<project>_<version>.mtar

Multitenancy (SaaS)

cds add multitenancy

Configuration:

{
  "cds": {
    "requires": {
      "multitenancy": true
    }
  }
}

Authorization Examples

// Service-level
@requires: 'authenticated-user'
service CatalogService { ... }

// Entity-level
@restrict: [
  { grant: 'READ' },
  { grant: 'WRITE', to: 'admin' }
]
entity Books { ... }

Bundled Resources

Reference Documentation (22 files)

1. references/annotations-reference.md - Complete UI annotations reference (10K lines)
2. references/cdl-syntax.md - Complete CDL syntax reference (503 lines)
3. references/cql-queries.md - CQL query language guide
4. references/csn-cqn-cxn.md - Core Schema Notation and query APIs
5. references/data-privacy-security.md - GDPR and security implementation
6. references/databases.md - Database configuration and deployment
7. references/deployment-cf.md - Cloud Foundry deployment details
8. references/event-handlers-nodejs.md - Node.js event handler patterns
9. references/extensibility-multitenancy.md - SaaS multitenancy implementation
10. references/fiori-integration.md - Fiori Elements and UI integration
11. references/java-runtime.md - Java runtime support
12. references/localization-temporal.md - i18n and temporal data
13. references/nodejs-runtime.md - Node.js runtime reference
14. references/plugins-reference.md - CAP plugins and extensions
15. references/tools-complete.md - Complete CLI tools reference
16. references/consuming-services-deployment.md - Service consumption patterns
17. references/service-definitions.md - Service definition patterns
18. references/event-handlers-patterns.md - Event handling patterns
19. references/cql-patterns.md - CQL usage patterns
20. references/cli-complete.md - Complete CLI reference
21. references/mcp-integration.md - MCP server setup and usage guide (new)
22. references/mcp-use-cases.md - Real-world MCP scenarios with quantified ROI (new)

Templates (8 files)

1. templates/bookshop-schema.cds - Complete data model example
2. templates/catalog-service.cds - Service definition template
3. templates/fiori-annotations.cds - UI annotations example
4. templates/mta.yaml - Multi-target application descriptor
5. templates/package.json - Project configuration template
6. templates/service-handler.js - Node.js handler template
7. templates/service-handler.ts - TypeScript handler template
8. templates/xs-security.json - XSUAA security configuration

Quick References

• CAP Documentation: https://cap.cloud.sap/docs/
• CDS Language: https://cap.cloud.sap/docs/cds/
• Node.js Runtime: https://cap.cloud.sap/docs/node.js/
• Java Runtime: https://cap.cloud.sap/docs/java/
• Best Practices: https://cap.cloud.sap/docs/about/best-practices
• GitHub Repository: https://github.com/cap-js/docs

Common CLI Commands

cds init [name]           # Create project
cds add <feature>         # Add capability
cds watch                 # Dev server with live reload
cds serve                 # Start server
cds compile <model>       # Compile CDS to CSN/SQL/EDMX
cds deploy --to hana      # Deploy to HANA
cds build                 # Build for deployment
cds env                   # Show configuration
cds repl                  # Interactive REPL
cds version               # Show version info

Best Practices

DO ✓

• Use cuid and managed aspects from @sap/cds/common
• Keep domain models in db/, services in srv/, UI in app/
• Use managed associations (let CAP handle foreign keys)
• Design single-purpose services per use case
• Start with SQLite, switch to HANA for production

DON'T ✗

• Don't use SELECT * - be explicit about projections
• Don't bypass CAP's query API with raw SQL
• Don't create microservices prematurely
• Don't hardcode credentials in config files
• Don't write custom OData providers

Version Information

• Skill Version: 2.1.0
• CAP Version: @sap/cds 9.4.x
• MCP Version: @cap-js/mcp-server 0.0.3+
• Last Verified: 2025-12-28
• License: GPL-3.0