# ARC-1 Diagram Sample

This workspace is only for generating the blog sample. Do not commit or push
anything. Do not edit the blog repository, the diagram skill repository, or the
ARC-1 repository.

## SAP Architecture Skill

Use the SAP architecture skill at:

`<path-to-btp-drawio-skill>/plugins/sap-architecture/skills/sap-architecture`

Before creating or editing a diagram, read that directory's `SKILL.md`
completely. Follow its six-step workflow and use its bundled references,
templates, assets, and scripts. The examples in the skill sometimes use a
`.claude/skills/...` path. In this workspace, replace that prefix with the
absolute skill path above.

The skill repository is read-only for this task. Put generated artifacts in
`outputs/` and temporary review files in `.cache/`.

For architecture verification, these local ARC-1 documents are available
read-only:

- `<path-to-arc-1>/docs_page/btp-cloud-foundry-deployment.md`
- `<path-to-arc-1>/docs_page/principal-propagation-setup.md`
- `<path-to-arc-1>/docs_page/enterprise-auth.md`

## Required Workflow

1. Parse the request into level, zones, services, flow, and focus application.
2. Run `scaffold_diagram.py` before creating any XML. Never author a draw.io
   file from scratch.
3. Prefer surgical relabeling and official bundled assets. Preserve the SAP
   template's frame, zone hierarchy, footer, colors, icon scale, and canvas.
4. Use `render_semantic.py --archetype on-prem-connectivity` only when no
   suitable SAP template can express the architecture without removing more
   than roughly one third of it. Explain this decision in the run report.
5. After the first complete adaptation, preserve a first-pass `.drawio`, PNG,
   validator output, and score output before making visual corrections.
6. Run autofix, validate, score, render, and inspect the PNG. A high score does
   not replace visual inspection.
7. Fix the worst visible or structural issue in one small iteration. Then run
   all checks again and preserve the final artifacts.
8. Do not claim the result is clean while validator warnings remain. Fix each
   warning or explain it in `outputs/run-report.md`.

## Architecture Accuracy

- VS Code is the remote MCP client on the developer workstation.
- ARC-1 runs as a Node.js application on SAP BTP Cloud Foundry.
- Client-to-ARC-1 transport is MCP Streamable HTTP over HTTPS at `/mcp`.
- XSUAA authenticates the MCP client and supplies the JWT and scopes.
- Destination Service resolves the on-premise destination and receives the
  user token for Principal Propagation.
- Connectivity Service provides the BTP connectivity proxy.
- SAP Cloud Connector is in the customer on-premise network.
- ARC-1 accesses the SAP ABAP system through ADT REST endpoints under
  `/sap/bc/adt/`. Do not label this backend flow as an OData business API.
- Principal Propagation maps the client identity to the SAP user. Keep the
  diagram generic and do not invent tenant names, hostnames, users, or systems.

## Visual Quality

- Use the official grey-circle SAP BTP service icons at normal SAP sizes.
- Use canonical SAP pills. MCP is teal; authentication and Principal
  Propagation are green; structural synchronous calls use the inherited SAP
  connector style.
- Do not route edges through cards, zone labels, icons, or the network divider.
- Keep labels readable and do not place icons over text.
- Use one synchronous edge for request and response when possible.
- Keep the flow narration outside the draw.io canvas.