sap-architecture/references/corpus-findings.md

SAP Reference Corpus Findings

Research snapshot: 2026-04-28.

Sources:

• SAP/btp-solution-diagrams at commit c9860da
• SAP/architecture-center at commit e76ce36
• SAP Community announcement: https://community.sap.com/t5/technology-blogs-by-sap/announcement-new-release-of-content-and-central-entry-point-for-sap-btp/bc-p/14011436

Corpus Size

The current public corpus contains 138 editable .drawio diagrams:

Source	.drawio files	Role
SAP/btp-solution-diagrams/assets/editable-diagram-examples	11	canonical BTP Solution Diagram examples
SAP/architecture-center/docs/ref-arch/**/drawio	127	Architecture Center reference architecture diagrams

The raw upstream draw.io corpus is about 24 MB. This plugin bundles a curated 71-template subset: all 11 canonical BTP examples, 52 Architecture Center templates chosen for broad SAP BTP coverage, and 8 curated external SAP-compatible reference examples.

What the Live Corpus Shows

Common page sizes:

Page size	Count	Use
1169 x 827	46	canonical landscape canvas; safest default
1100 x 850	22	Architecture Center landscape variant
1654 x 1169	17	large A3-style landscape
850 x 1100	15	portrait variant
827 x 1169	13	canonical portrait variant

Top observed colors outside embedded SVG icon payloads:

Hex	Count	Meaning / note
#475E75	2167	non-SAP area border / neutral stroke
#1D2D3E	2139	title / primary text
#FFFFFF	1865	card fill / background
#0070F2	1627	SAP / BTP area border
#188918	782	positive / authentication flow
#F5F6F7	576	non-SAP area fill
#EBF8FF	525	SAP / BTP area fill
#00185A	503	dark SAP blue variant used in Architecture Center diagrams
#5D36FF	467	indigo / authorization flow
#266F3A	402	dark positive green variant
#CC00DC	323	pink / trust flow

Observed font families:

Font	Count	Guidance
Helvetica	3494	default for generated diagrams
Arial	1978	appears in SAP files, often inside rich text labels
72 Brand	124	appears in some newer Architecture Center files; do not introduce unless inherited from a template

Observed stroke widths:

Stroke width	Count	Guidance
1.5	5902	dominant border / connector weight
2	627	secondary connector / emphasis
1	456	pills, small cards, light dividers
3	86	heavy emphasis
4	10	firewall / very heavy boundary

Implementation Decisions

• Keep 1169 x 827 as the default canvas because it is both the canonical BTP examples' size and the most common live corpus size.
• Keep Helvetica as the generated-diagram default. Arial and 72 Brand are accepted as inherited upstream-template variants but should not be newly introduced by the skill.
• Expand the validator palette with observed SAP variants such as #00185A, #0057D2, #2395FF, #D1EFFF, and common neutral variants so the validator does not fight real Architecture Center files.
• Validate duplicate IDs per draw.io page, not globally across the entire .mxfile; multi-page upstream files can reuse 0 / 1 root IDs safely.
• Bundle representative templates rather than every raw upstream diagram. The full corpus can still be used for research by cloning the SAP repos and passing them to score_corpus.py --references.

Operational Loop

For a generated candidate:

1. Run select_reference.py on the user's request and pick from the top 3 candidates.
2. Copy the selected template and preserve geometry, canvas, container rhythm, legend style, and line/pill density.
3. Relabel and replace only the content required by the user's scenario.
4. Run autofix.py --write.
5. Run validate.py.
6. Run score_corpus.py --min-score 90.
7. If the score is below 90, use compare.py against the selected template and restore the dimensions that drifted.

The point of the loop is not to make every generated diagram identical. It is to keep the structural fingerprint close enough that a new diagram reads as part of the SAP Architecture Center system rather than as a generic draw.io sketch.