AWS Architecture Diagram

Instructions

Generate a draw.io (.drawio) XML file representing an AWS architecture diagram.

Layout

• Left-to-right flow for data/request path
• UI/Frontend on the LEFT (users access from left side)
• Data sources / external systems on the RIGHT
• Use horizontal lanes for parallel paths (top lane, bottom lane)
• Minimum 220px horizontal spacing between icons (to leave room for edge labels)
• Minimum 250px vertical spacing between lanes (so vertical edges don't crowd)
• Secondary/auxiliary services (monitoring, DLQ, error paths) go BELOW the main flow with 280px+ vertical gap

Canvas

• Large canvas: pageWidth="2400" pageHeight="1400" minimum
• Set dx="2800" dy="1600" for proper viewport
• Always include a title block as the first element after the background:

<mxCell value="&lt;b&gt;Diagram Title&lt;/b&gt;&lt;br&gt;Author | Date | Version" style="text;html=1;align=left;verticalAlign=top;whiteSpace=wrap;rounded=0;fontSize=14;spacing=8;" vertex="1" parent="1">
  <mxGeometry x="40" y="30" width="420" height="60" as="geometry" />
</mxCell>

Icon Style

• Icons are from draw.io's built-in mxgraph.aws4 stencil library — the official AWS Architecture Icons (https://aws.amazon.com/architecture/icons/, updated quarterly)
• Icon size: 78x78px for main services, 65x65px for secondary
• Use sketch=0 on all icons
• Use strokeColor=#ffffff on all AWS service icons
• Font size: 12px for labels

Edge Style — CRITICAL FOR CLEAN DIAGRAMS

Base edge style (all edges):

edgeStyle=orthogonalEdgeStyle;rounded=1;orthogonalLoop=1;jettySize=auto;html=1;strokeWidth=2;exitX=1;exitY=0.5;exitDx=0;exitDy=0;entryX=0;entryY=0.5;entryDx=0;entryDy=0;

Rules for edge labels:

• Keep labels SHORT (1-2 words max). Use icon labels for detail, not edge labels.
• On horizontal edges: position label ABOVE the line using verticalAlign=bottom; in the edge style
• On vertical edges: position label to the LEFT using align=right; in the edge style
• Always add labelBackgroundColor=#F5F5F5; so labels don't overlap lines
• For edges WITHOUT labels: omit the value attribute entirely (don't use value="")

Edge label positioning (prevents overlap with icons):

<mxCell value="Label" style="edgeStyle=orthogonalEdgeStyle;rounded=1;orthogonalLoop=1;jettySize=auto;html=1;strokeWidth=2;labelBackgroundColor=#F5F5F5;fontSize=11;" edge="1" source="a" target="b" parent="1">
  <mxGeometry relative="1" as="geometry" />
</mxCell>

For edges that go to services ABOVE or BELOW the main flow:

• Use explicit exit/entry points to control routing:
  • Exit bottom: exitX=0.5;exitY=1;exitDx=0;exitDy=0;
  • Enter top: entryX=0.5;entryY=0;entryDx=0;entryDy=0;
  • Exit top: exitX=0.5;exitY=0;exitDx=0;exitDy=0;
  • Enter bottom: entryX=0.5;entryY=1;entryDx=0;entryDy=0;
• This prevents draw.io from routing lines through other icons

Edge types:

• Solid black (strokeWidth=2): primary data flow
• Dashed black (strokeWidth=2;dashed=1;): optional/async path
• Dashed red (strokeWidth=2;dashed=1;strokeColor=#DD344C;): error path

When NOT to label edges:

• If the flow is obvious from context (e.g., Lambda → DynamoDB doesn't need "Write")
• If the icon labels already explain the relationship
• Prefer fewer, more meaningful labels over labeling every edge

Two Icon Patterns — CRITICAL

Pattern 1: Service-level (resourceIcon frame)

• Style: shape=mxgraph.aws4.resourceIcon;resIcon=mxgraph.aws4.<name>
• MUST use strokeColor=#ffffff — without it, the white glyph disappears
• Size: 78x78

Pattern 2: Resource-level (standalone shape)

• Style: shape=mxgraph.aws4.<name> directly (no resIcon)
• MUST use strokeColor=none — using #ffffff breaks these
• Size: 78x78 or 48x48

Confusing these patterns guarantees broken icons.

Icon Reference Files (load by category as needed)

• references/aws-icons-compute.md — Lambda, EC2, ECS, EKS, Fargate
• references/aws-icons-database.md — DynamoDB, RDS, Aurora, ElastiCache
• references/aws-icons-integration.md — API Gateway, SQS, SNS, EventBridge, Step Functions
• references/aws-icons-networking.md — CloudFront, Route 53, VPC, ELB
• references/aws-icons-storage.md — S3, EFS, EBS, Glacier, Backup
• references/aws-icons-security.md — IAM, Cognito, KMS, WAF, Shield
• references/aws-icons-analytics-ml.md — Kinesis, Athena, Bedrock, SageMaker
• references/aws-icons-common.md — Groups, general resources, edge styles, base template

Always look up icons from reference files. Never guess icon names.

Group Boundaries

• AWS Cloud: shape=mxgraph.aws4.group;grIcon=mxgraph.aws4.group_aws_cloud_alt;strokeColor=#232F3E;fillColor=none
• Account: shape=mxgraph.aws4.group;grIcon=mxgraph.aws4.group_account;strokeColor=#CD2264;fillColor=none
• On-premise: shape=mxgraph.aws4.group;grIcon=mxgraph.aws4.group_on_premise;strokeColor=#5A6C86;fillColor=none
• Logical groups: Simple dashed boxes: whiteSpace=wrap;html=1;fillColor=none;dashed=1;dashPattern=8 8
• NO colored backgrounds on group boxes — always fillColor=none

PNG Export Background Fix

Place a full-canvas rectangle as the FIRST element (lowest z-order):

<mxCell value="" style="rounded=0;whiteSpace=wrap;html=1;fillColor=#F5F5F5;strokeColor=none;" vertex="1" parent="1">
  <mxGeometry x="0" y="0" width="2400" height="1400" as="geometry" />
</mxCell>

This prevents black background on PNG export. Use strokeColor=none (not E0E0E0).

Multi-page Diagrams

For complex architectures, use multiple pages (tabs) in one .drawio file:

<mxfile>
  <diagram id="overview" name="Overview">...</diagram>
  <diagram id="networking" name="Networking Detail">...</diagram>
  <diagram id="data-flow" name="Data Flow">...</diagram>
</mxfile>

• Page 1: High-level overview (service-level icons only)
• Page 2+: Detail views (resource-level icons, subnet layouts, etc.)

Edge Legend (optional, for complex diagrams)

Place below the title block if the diagram has multiple edge types:

• Solid line: primary data flow
• Dashed line: optional/async
• Red dashed: error path

File Splitting

Since draw.io XML can be large, split creation across multiple tool calls:

1. Header + left side (frontend, delivery layer)
2. Middle (processing lambdas, database)
3. Right side (ingest, messaging, data sources)
4. Bottom (optional/outbound flows) + close XML

Audience Mode

Before generating, assess the target audience:

• Technical: Use service names, protocol labels (HTTPS, gRPC), CIDR blocks, instance types
• Non-technical: Use action labels ("Store Data", "Send Notification"), hide implementation details, use numbered flow (① ② ③)

If unclear, ask: "Technical audience or executive/non-technical?"

Numbered Flow Edges (for non-technical mode)

Instead of technical labels, show flow order with circled numbers:

• Flow A: ① → ② → ③ → ④ (white circled numbers)
• Flow B: ❶ → ❷ → ❸ → ❹ (black circled numbers for second flow)

Use edge labels: value="①" with fontSize=14;fontStyle=1;labelBackgroundColor=#ffffff;

Companion Guide

After generating the .drawio file, also generate a markdown guide:

• Same filename with .md extension (e.g., serverless-api.drawio + serverless-api.md)
• Contents: diagram title, flow description (numbered steps matching edge labels), service list with purpose, key design decisions

Two-Step Edit Approach

After generating the initial .drawio file:

1. Export to PNG using the draw.io CLI (see Output section)
2. Review the PNG visually — check for empty/broken icons, overlapping edges, misaligned labels
3. Fix issues in the .drawio XML and re-export

This catches rendering problems (wrong stencil names, broken styles) that are invisible in raw XML.

Icon Name Gotchas — CRITICAL

draw.io stencil names do NOT always match current AWS service names. Services that were renamed keep their legacy stencil names:

Rule: Always verify icon names from the reference files. If a service icon renders as an empty box, the stencil name is wrong. Check the draw.io source at src/main/webapp/js/diagramly/sidebar/Sidebar-AWS4.js for the canonical name.

Validation Step

After generating XML, mentally verify:

1. Every resIcon= value exists in the reference files
2. Service-level icons have strokeColor=#ffffff
3. Resource-level icons have strokeColor=none
4. No XML comments present
5. All cell IDs are unique
6. Every edge has <mxGeometry relative="1" as="geometry" />
7. No icon uses a guessed stencil name — all verified against reference files

Output

• Save with descriptive filename ending in .drawio
• Open with open command (macOS) or xdg-open (Linux) after creation
• For PNG/SVG/PDF export, use draw.io CLI:
  • macOS: /Applications/draw.io.app/Contents/MacOS/draw.io -x -f png -e -b 10 -o output.drawio.png input.drawio
  • Linux: drawio -x -f png -e -b 10 -o output.drawio.png input.drawio Flags: -x export, -f format, -e embed diagram XML, -b 10 border
• Exported files use double extension: name.drawio.png (signals embedded XML, re-editable in draw.io)

XML Well-formedness (CRITICAL)

• NEVER include XML comments (<!-- -->) — they cause parse errors
• Escape special characters in values: & < > "
• Always use unique id values for each mxCell
• Every edge MUST have <mxGeometry relative="1" as="geometry" /> as child element
• Basic structure must include root cells id="0" and id="1" (parent="0")

Official Reference

• Full XML/style reference: https://raw.githubusercontent.com/jgraph/drawio-mcp/main/shared/xml-reference.md
• Style properties: https://raw.githubusercontent.com/jgraph/drawio-mcp/main/shared/style-reference.md

Source: vidanov/aws-architecture-diagram-skill — distributed by TomeVault.