Render Big Block — Solution Architecture Diagram (v1.0)

Render a big-block-brief.md (v1.0) into a structured Excalidraw diagram. The Big Block is a data-driven grid — tier bands with solution blocks, path connections, SPIs, foundations, and a roadmap timeline. This is fundamentally different from the Big Picture's illustrated landscape: here, precision and clarity matter more than artistic expression.

Parameters

Parameter	Required	Description
brief_path	Yes	Path to big-block-brief.md
output_path	No	Path for .excalidraw output (default: {brief_dir}/big-block.excalidraw)

Output

Return a single-line JSON response:

Success:

{"ok":true,"excalidraw_path":"{path}","share_url":"{url}","solutions":{N},"tiers":[{t1},{t2},{t3},{t4}],"connections":{N},"elements":{count},"color_mode":"{mode}"}

Error:

{"ok":false,"e":"{error}","phase":"{phase_number}"}

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Pipeline Overview

The pipeline renders the Big Block in 9 sequential phases. Element count targets are specified per section to ensure consistent output.

Phase 1: Parse & Setup              → 1 element            Extract all data from brief
Phase 2: Title Banner               → 5 elements            Dark banner + title + subtitle + scoring + accent
Phase 3: Tier Bands                 → 2 per tier (8 total)  Background band + tier label
Phase 4: Solution Blocks            → 6 per block           Rect + name + score/stars + category + portfolio + wave
Phase 5: Path Connections           → 1-2 per connection    Line + optional label
Phase 6: SPI + Foundation Cards     → 3 per SPI, 4 per fdn  Card + name + link(s) [+ maturity for fdns]
Phase 7: Roadmap Timeline           → 3 + 3 + N badges      Wave bands + labels + solution pills
Phase 7.5: Visual Validation        → 0 elements            Screenshot review checkpoint
Phase 8: Footer + Export            → 4 elements            Background + customer + date + methodology

Target element counts (use these to self-check after each phase):

• 9-solution brief (A1): ~145 elements (1 + 5 + 8 + 54 + 12 + 27 + 15 + 0 + 4 = ~126 minimum)
• 3-solution brief (A2): ~70 elements

Save snapshots at every phase boundary for recovery. Use snapshot_scene after each phase — this enables restore_snapshot if a later phase fails.

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Phase 1: Parse & Setup

Why: This phase converts the brief's structured data into computed positions and a color palette that all subsequent phases depend on. Getting tier heights and block grid positions right here prevents cascading layout errors in later phases.

Step 1.1: Read and Parse Brief

1. Read brief_path via Read tool
2. Parse YAML frontmatter — extract ALL of:
   • title, subtitle
   • customer, provider, industry, language
   • canvas_size (A0/A1/A2/A3), canvas_pixels (width x height)
   • theme, theme_path
   • scoring (formula, solutions_ranked, avg_ranking, portfolio_gaps)
   • generated date
3. Parse markdown body — extract into structured data:
   • Tiers: tier_id, tier_label, tier_label_de, solution_count
   • Blocks: block_id, name, name_short, br_score, br_stars, category, portfolio_ref, portfolio_status, foundation_factor, paths[], wave, spis[], foundations[]
   • SPIs: spi_id, name, name_de, linked_solutions[], description
   • Foundations: foundation_id, name, name_de, maturity_required, dependent_solutions[], description
   • Connections: path_id, path_name, blocks[], color
   • Waves: wave number, label, label_de, timeline, blocks[], description
4. Validate: every block_id in connections exists, every SPI/foundation link resolves

Step 1.2: Load Layout Spec

Read $CLAUDE_PLUGIN_ROOT/libraries/big-block-layouts.md. Look up:

• Canvas dimensions for the brief's canvas_size
• Zone specifications (title banner, tier zone, SPI/foundation zone, roadmap zone, footer)
• Block dimensions (width, height, corner radius, margin)
• Text sizing table
• Color specifications for light/dark mode

Step 1.3: Detect Color Mode

If theme_path exists, read it and extract background color. Apply luminance formula:

luminance = 0.299*R + 0.587*G + 0.114*B
if luminance < 128 → "dark" mode
else → "light" mode

If no theme found, default to light mode.

Build a color palette object from the layouts spec's color tables for the detected mode. This palette is used by all subsequent phases.

Step 1.4: Compute Tier Band Heights

Distribute tier zone height proportionally to solution count per tier, respecting minimum heights from the layouts spec:

• Tier 1: min 30%
• Tier 2: min 25%
• Tier 3: min 22%
• Tier 4: min 15%

If a tier has 0 solutions, collapse to 30px label-only row.

Compute exact y-position and height for each tier band within the Tier Zone.

Step 1.5: Compute Block Grid Positions

For each tier, lay out blocks in a grid:

• Blocks per row from layouts spec (e.g., A1 = 5 max)
• Center blocks horizontally within the tier band
• Vertical center within the band
• Apply margin between blocks

Record the (x, y, width, height) of every block — this is needed for connection routing in Phase 5.

Step 1.6: Initialize Canvas

Why: The Excalidraw canvas is a shared resource — if a previous rendering left elements behind, they would corrupt the new diagram. Starting with clear_canvas guarantees a clean slate.

1. Run via Bash: mkdir -p "{output_dir}"
2. Call clear_canvas first, before any other Excalidraw MCP call, because it ensures no stale elements contaminate the new diagram
3. Call read_diagram_guide — load Excalidraw best practices
4. Create canvas frame rectangle:

   type: rectangle
   x: 0, y: 0
   width: {canvas_width}, height: {canvas_height}
   backgroundColor: "#F7F7F7" (light) or "#0D0D0D" (dark)
   strokeColor: "transparent"
   strokeWidth: 0
   roughness: 0
   

5. Call snapshot_scene name="phase1-setup"

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Phase 2: Title Banner

Why: The banner is the first element viewers see and establishes the color mode and branding context that all subsequent elements inherit.

The title banner is a dark bar across the top with white text, followed by an accent-colored separator.

Elements to create:

1. Banner background — rectangle, full width, solid #1A1A1A
2. Title text — brief's title field, font size from layouts spec
3. Subtitle text — brief's subtitle field, smaller font
4. Scoring line — "{N} Lösungen | Ø BR {avg} | {gaps} Portfolio-Lücken" (or English equivalent)
5. Accent border — thin rectangle below banner, full width, theme accent color

Use batch_create_elements with all 5 elements. Group them as "title-banner".

Save snapshot: "phase2-banner"

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Phase 3: Tier Bands

Why: Tier bands create the visual hierarchy that communicates Business Relevance at a glance — Tier 1 at the top draws the eye first, reinforcing the prioritization from the value-modeler ranking.

Create the horizontal tier bands within the Tier Zone. Each band gets a tinted background and a tier label.

For each tier (1-4):

1. Band background — rectangle at computed (x, y, width, height), tinted with tier color at opacity from layouts spec
2. Tier label — text at left margin, vertically centered in band. Include tier name + BR range.
   • German: "Stufe 1: Geschäftskritisch (BR >= 4.0)"
   • English: "Tier 1: Mission Critical (BR >= 4.0)"

Use batch_create_elements for all tier bands + labels (8-16 elements).

Group each tier's elements (band bg + label) as "tier-{N}".

Save snapshot: "phase3-tiers"

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Phase 4: Solution Blocks

Why: Each block is the atomic information unit of the diagram. Positioning it in the correct tier band is what makes the Big Block useful as a decision tool — stakeholders can scan from top to bottom in order of business relevance.

This is the core visual content. Each solution block is a rounded rectangle with structured internal text.

For each block:

Create these elements at the block's computed grid position:

1. Block background — rounded rectangle (cornerRadius from spec)

   • Stroke color: tier color at 60% (light) or 80% (dark)
   • If portfolio_status: gap: stroke color = red (#E53E3E / #FC8181)
   • Fill: #FFFFFF (light) or #1A1A1A (dark)

2. Solution name — bold text, name_short value, top of block

3. BR score + stars — "BR: {score} {stars}"

   • Stars: filled ★ in amber (#F6AD55), empty ☆ in gray
   • Use br_stars for filled count, pad to 5 total

4. Category tag — "Category: {category}" in muted text

5. Portfolio reference — either:

   • "→ {portfolio_ref}" in green (#38A169 / #68D391) if mapped
   • "PORTFOLIO GAP" in red (#E53E3E / #FC8181) if gap

6. Wave + paths — "Wave {N} | {count} paths" in smallest font, bottom of block

Use batch_create_elements in batches of up to 50 elements (roughly 7-8 blocks per batch at ~7 elements each).

Group each block's elements as "block-{block_id}".

Save snapshot: "phase4-blocks"

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Phase 5: Path Connections

Why: Connection lines reveal shared TIPS paths between solutions, exposing synergies that are invisible in the flat ranking list. A stakeholder seeing two Tier 1 solutions linked by the same path can prioritize them as a package.

Draw dashed bezier lines between blocks that share a TIPS path. Connections are rendered BEHIND blocks (lower z-order — they were created before blocks, but since we created blocks after tier bands, we need to ensure connections sit between tier bands and blocks visually).

Connection routing strategy:

1. For each connection, identify the block positions of all linked blocks
2. For 2-block connections: single curved line between block centers
3. For 3+ block connections: hub-and-spoke from the highest-tier block to each other block
4. Route lines to exit from block edges (not centers) — prefer bottom/top edges for cross-tier connections, left/right for same-tier connections
5. Use Excalidraw arrow elements with startArrowhead: null, endArrowhead: null for bidirectional lines

Connection styling:

• strokeStyle: "dashed"
• strokeWidth: 2
• strokeColor: tier color of highest-tier block in connection
• opacity: 40 (light) or 60 (dark)

Connection priority (if > 8 connections):

1. All Tier 1 connections (always shown)
2. Cross-tier connections
3. Drop intra-tier lower-tier connections

Optional: path label at midpoint

• Small text (8px A1) with path_name
• Only add labels if there's visual space (≤ 6 connections)

Use batch_create_elements for all connections.

Save snapshot: "phase5-connections"

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Phase 6: SPI + Foundation Cards

Why: SPIs and foundations are the enablers that make solutions viable. Placing them below the tier grid creates a visual dependency stack — stakeholders see what organizational changes and infrastructure prerequisites must be in place before solutions can deliver value.

SPIs (left half of SPI/Foundation Zone)

For each SPI, create a card:

1. Card background — rounded rectangle, red-tinted (#FFF5F5 / #2D1B1B)
2. SPI name — bold text, red tone (#C53030 / #FC8181)
3. Linked solutions — "→ {solution names}" in muted text

Layout: cards arranged in a 2-column grid within the left half of the zone.

Foundations (right half of SPI/Foundation Zone)

For each Foundation, create a card:

1. Card background — rounded rectangle, blue-tinted (#EBF8FF / #1A2332)
2. Foundation name — bold text, blue tone (#2B6CB0 / #63B3ED)
3. Maturity level — "Maturity: {level}" in muted text
4. Dependency count — "→ {N} solutions depend" in muted text

Layout: cards arranged in a 2-column grid within the right half of the zone.

Section labels

Add "Process Changes (SPIs)" / "Prozessanpassungen" label above SPI cards. Add "Foundation Requirements" / "Voraussetzungen" label above Foundation cards.

Use batch_create_elements for all SPI + Foundation elements.

Group SPIs as "spi-section", Foundations as "foundation-section".

Save snapshot: "phase6-cards"

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Phase 7: Roadmap Timeline

Why: The timeline converts abstract wave assignments into a temporal sequence that stakeholders can commit to. Without it, the tier grid shows what matters but not when to act.

The roadmap is a horizontal timeline at the bottom showing implementation waves.

Elements:

1. Timeline background — full-width rectangle in the Roadmap Zone
2. Wave bands — 3 proportional segments (Wave 1: narrowest for 0-6mo, Wave 2: medium for 6-18mo, Wave 3: widest for 18-36mo)
   • Proportional widths: Wave 1 = 6/36, Wave 2 = 12/36, Wave 3 = 18/36
3. Wave labels — bold text: "Wave 1: Quick Wins" (or German equivalent)
4. Timeline labels — muted text: "0-6 Monate", "6-18 Monate", "18-36 Monate"
5. Solution badges — small pill/text for each solution in the wave, using name_short

Use batch_create_elements for all roadmap elements.

Group as "roadmap".

Save snapshot: "phase7-roadmap"

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Phase 7.5: Visual Validation

Why: A screenshot checkpoint catches layout issues (overlapping blocks, misaligned tier bands, invisible connections) before export, avoiding the cost of re-running the full pipeline.

After rendering all content (Phases 2-7), take a screenshot to verify the diagram looks correct before exporting.

1. Call get_canvas_screenshot — this returns a visual snapshot of the current canvas
2. Review the screenshot for obvious issues:
   • Are all tier bands visible and properly stacked (Tier 1 top → Tier 4 bottom)?
   • Are solution blocks positioned within their tier bands (not overlapping band borders)?
   • Are connection lines visible between blocks?
   • Is the title banner at the top, footer area at the bottom?
   • Do SPI/Foundation cards appear below the tier zone?
3. If issues are detected, use update_element or delete_element to fix before exporting
4. Call snapshot_scene name="phase7.5-validated"

This phase adds no elements — it's a quality gate. Skip only if get_canvas_screenshot is unavailable.

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Phase 8: Footer + Export

Why: The footer closes the canvas with attribution and methodology provenance — a diagram without metadata looks unfinished and loses traceability to the TIPS analysis that produced it.

Step 8.1: Footer

Create footer elements:

1. Footer background — subtle rectangle
2. Customer/Provider — left-aligned: "{customer} | {provider}"
3. Date — center-aligned: "{generated}"
4. Methodology — right-aligned: "TIPS Business Relevance — WO2018046399A1"

Use batch_create_elements. Group as "footer".

Save snapshot: "phase8-footer"

Step 8.2: Export .excalidraw File

Primary method — use export_scene:

export_scene:
  filePath: "{output_path}"

Fallback — if export_scene fails or is unavailable, use describe_scene to get the element data, then write the .excalidraw JSON file directly via Write tool. The .excalidraw format is:

{
  "type": "excalidraw",
  "version": 2,
  "source": "render-big-block",
  "elements": [... all elements from describe_scene ...],
  "appState": {"viewBackgroundColor": "{palette.canvas_frame_bg}"}
}

Step 8.3: Element Count Verification

Call describe_scene and count elements. Compare against the target counts from the Pipeline Overview. Log the final count in the result JSON.

Step 8.4: Generate Shareable URL

Call export_to_excalidraw_url. If unavailable, set share_url to "n/a" in the result.

Step 8.5: Return Result JSON

{"ok":true,"excalidraw_path":"{output_path}","share_url":"{url}","solutions":{N},"tiers":[{t1},{t2},{t3},{t4}],"connections":{conn_count},"elements":{total},"color_mode":"{mode}"}

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Constraints

• Render via Excalidraw MCP tools — use batch_create_elements, group_elements, snapshot_scene, export_scene etc. MCP maintains element IDs, grouping, and z-order that manual JSON writing cannot guarantee. Only fall back to manual JSON if MCP export fails (see Step 8.2 fallback).
• Preserve brief content verbatim (solution names, scores, path names) — the data IS the content. Altering solution names or scores would break the diagram's integrity as a faithful representation of the value-modeler output.
• Follow z-order from big-block-layouts.md: canvas frame → banner → tier bands → tier labels → connections → blocks → SPI cards → foundation cards → roadmap → footer. Create elements in this order so earlier elements are behind later ones.
• Use roughness: 0 for all elements — the Big Block is a precise data-driven diagram, not a hand-drawn illustration. Roughness would undermine the structured grid aesthetic.
• Use fontFamily: 2 (Helvetica/sans-serif) for all text — clean, professional typography that matches the precision of the grid layout.
• Group elements after each phase using group_elements — groups make the diagram editable (users can select and move entire blocks/sections). Group IDs: "title-banner", "tier-{N}", "block-{block_id}", "spi-section", "foundation-section", "roadmap", "footer".
• Batch create elements (up to 50 per call) for efficiency.
• Save snapshots at every phase boundary via snapshot_scene — enables restore_snapshot recovery without re-rendering completed phases.
• Support both German and English labels based on brief's language field.
• Return JSON-only response (no prose) — the calling agent parses output programmatically.