CAPforge

MCP server that makes your AI agent (Claude Code, Cursor, …) get SAP CAP/CDS right: scaffolding that follows real conventions, plus real validation against cds compile. The agent doesn't stop until the code compiles clean.

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It calls no LLM itself: your agent brings the model (BYOK). Zero inference cost, nothing leaves your machine.

Why

General-purpose models hallucinate CDS — annotation terms that don't exist, OData v2 syntax mixed into v4, invented fields — because there's barely any public CAP code in training data. CAPforge gives your agent the two things it's missing:

1. Curated, sourced knowledge — modern CAP/UI5 best practices distilled from official SAP docs (capire, OData vocabularies, reference samples), every rule with its source URL.
2. A real feedback loop — tools that run the actual compiler and linter and feed errors back until everything is green.

Tools

Tool	What it does
cap_project_context	Codebase-aware: compiles your real project to CSN and returns the existing model (services, entities, fields, associations) so the agent reuses instead of inventing
cap_scaffold_entity	Generates all 5 layers of an entity following conventions: CDS model with aspects (cuid, managed), projection, annotations.cds (HeaderInfo, LineItem, Facets, FieldGroups), mock CSV, i18n
cap_write_files	Writes files into the project
cap_validate	Runs cds compile and returns errors (the loop)
cap_lint	Runs cds lint (best practices / anti-patterns)
cap_deploy_check	Layer 3: deploys to a throwaway sqlite DB and loads the mock CSVs — catches what compile can't (CSV columns that don't exist, bad data, duplicate keys)
cap_analyze_legacy_ui5	Migration mode: inventories a legacy freestyle UI5 app (read-only) — datasources, sections, columns, bound fields, value helps, actions, i18n
ui5_scaffold_section	Generates a freestyle ObjectPage section (SmartTable with p13nData, or SimpleForm) + handler stubs + i18n
ui5_validate_view	The UI5 loop: well-formed XML + every declared event handler exists in the controller
ui5_lint	Layer 3: runs SAP's official ui5lint — deprecated APIs, UI5 2.x readiness, CSP issues
resource conventions://cap	Canonical knowledge core + your team's convention profile + migration map

Normal flow: context → scaffold → write → validate → correct → until green. Migration flow: analyze_legacy → context (target) → propose map (REUSED / NEW / DISCARDED) → scaffold → validate.

Requirements

• Node.js 18+
• @sap/cds-dk available (globally or in the project) for cap_validate to work.

Install & try

npm install
node test-loop.js   # full-loop demo against the bundled sandbox

VS Code / SAP Business Application Studio

The extension/ folder ships a VS Code extension that registers the MCP server automatically (no mcp.json editing) for Copilot agent mode and any MCP client. Build it locally until it lands on the Marketplace / Open VSX:

cd extension && npm install && npx vsce package
code --install-extension capforge-0.1.3.vsix

Point the capforge.conventionsPath setting to your team's private conventions (Pro preview). BAS note: BAS installs extensions from Open VSX, but its AI assistant does not consume MCP servers natively yet — the extension is ready for the day it does.

Claude Code / Cursor

Register in Claude Code (project .mcp.json or global config):

{
  "mcpServers": {
    "capforge": {
      "command": "npx",
      "args": ["-y", "capforge"]
    }
  }
}

Load your team's private conventions (a preview of the Pro tier):

"env": { "CAPFORGE_CONVENTIONS": "PATH/to/team-conventions.md" }

Knowledge

• knowledge/ — canonical core: modern CAP/UI5 best practices (aspects, compositions, drafts, authorization, Fiori annotations, i18n, tooling, migration map), anchored to official SAP docs with cited sources.
• conventions/ — house profile: one team's style, overridable via CAPFORGE_CONVENTIONS. Wins over the core on style conflicts.

The conventions://cap resource serves both, combined, to the agent.

Free vs Pro

• Free (open source): all the tools + the canonical knowledge core.
• Pro: private team profile, codebase-aware generation at scale, migration mode, CI checks, support. Coming soon.

License

MIT.