# Prompt: ARC-1 on SAP BTP Cloud Foundry

Create an L2 SAP Architecture Center-style diagram for the architecture below.
Use the SAP architecture skill configured in `AGENTS.md` and follow its complete
workflow. Do not stop after copying a template. Adapt it to this scenario,
validate it, render it, inspect the image, and make one focused improvement.

## Audience and Scope

The audience is an SAP platform and ABAP development team. The diagram should
explain how a developer in VS Code reaches an on-premise SAP ABAP system through
a centrally deployed ARC-1 instance.

Use a concrete read-only example: the developer asks the AI assistant in VS Code
to inspect an ABAP class. VS Code sends an MCP tool call to ARC-1, and ARC-1
reads the object through the ADT REST API.

## Required Zones and Components

### Developer Workstation

- Developer
- VS Code
- MCP-capable AI assistant

### SAP BTP Cloud Foundry

- ARC-1 application as the focus application
- XSUAA
- Destination Service
- Connectivity Service

### Customer On-Premise Network

- SAP Cloud Connector
- SAP ABAP System

Keep the backend generic. Do not call it SAP S/4HANA or ECC unless a selected
SAP template requires a generic product label that cannot be safely replaced.

## Numbered Flow

1. The developer signs in through XSUAA and the configured BTP trust.
2. VS Code sends an MCP tool call to the ARC-1 `/mcp` endpoint using Streamable
   HTTP over HTTPS and includes the XSUAA JWT.
3. ARC-1 validates the JWT and its scopes.
4. ARC-1 passes the user token to Destination Service and resolves the
   `PrincipalPropagation` destination.
5. ARC-1 uses Connectivity Service to route the request through SAP Cloud
   Connector.
6. Cloud Connector propagates the user's identity to the SAP system.
7. ARC-1 reads the requested ABAP object through an ADT REST endpoint under
   `/sap/bc/adt/` as the mapped SAP user.
8. The result returns through ARC-1 to the AI assistant in VS Code.

## Diagram Constraints

- Title: `ARC-1 on SAP BTP Cloud Foundry`
- Subtitle: `VS Code to an on-premise SAP ABAP system with Principal Propagation`
- ARC-1 is the visual focus and may use the SAP purple accent.
- VS Code to ARC-1 uses a canonical teal `MCP` pill.
- XSUAA authentication and Principal Propagation use canonical green labels.
- Do not label the backend connection `OData/REST`. Use `ADT REST` or `HTTPS`
  in the narration and the closest canonical pill supported by the SAP assets.
- Cloud Connector belongs in the on-premise zone.
- Destination Service and Connectivity Service belong in the BTP zone.
- Use one edge per logical synchronous hop. Do not add separate return arrows.
- Do not route arrows through cards, labels, icons, or zone boundaries.
- Preserve the selected SAP template's canvas, frame, footer, and visual grammar.
- Keep the canvas focused on this one flow. Do not add CI/CD, databases, Joule,
  Integration Suite, or unrelated SAP services.
- Put the detailed numbered flow in Markdown below the diagram, not inside it.

## Required Execution and Evidence

Use the full prompt text above as input to `scaffold_diagram.py`. Report the top
three template candidates and explain the selected template. Prefer a suitable
SAP template. Use the deterministic `on-prem-connectivity` semantic fallback
only when the template geometry is clearly unsuitable.

Create the first complete adapted diagram, then preserve these files before any
visual correction:

- `outputs/arc-1-btp-cf-onprem-first-pass.drawio`
- `outputs/arc-1-btp-cf-onprem-first-pass.png`
- `outputs/first-pass-validation.txt`
- `outputs/first-pass-score.txt`

Run autofix, validation, scoring, and rendering. Inspect the first-pass PNG with
the available image-viewing tool. Identify the single worst visible or
structural problem. Make one focused correction, rerun every check, and create:

- `outputs/arc-1-btp-cf-onprem-final.drawio`
- `outputs/arc-1-btp-cf-onprem-final.png`
- `outputs/final-validation.txt`
- `outputs/final-score.txt`
- `outputs/arc-1-btp-cf-onprem-flow.md`
- `outputs/run-report.md`

Also generate a side-by-side visual review under `outputs/review/` using
`render_compare.py` or `iterate.py` with the selected SAP reference.

`outputs/run-report.md` must contain:

- diagram skill Git commit
- selected template and alternatives
- whether template scaffolding or semantic fallback was used
- first-pass validator summary and scores
- the visible issue found in the rendered first pass
- the one correction made
- final validator summary and scores
- every remaining warning and why it was accepted
- total number of correction iterations
- a placeholder for the exact Codex model label if Codex cannot determine it

Do not invent the Codex model name. Write `Record from the Codex UI` when the
runtime does not expose it.

Finish only when the final `.drawio` opens correctly, the PNG is nonblank and
readable, validation has no errors, the appropriate quality score passes 90,
and all remaining warnings are documented.