Feat/add mermaid chart rendering (#5377)

Signed-off-by: Arya Pratap Singh <notaryasingh@gmail.com>

crates/goose-mcp/src/autovisualiser/mod.rs

@@ -387,6 +387,13 @@ pub struct ShowChartParams {
     pub data: ChartData,
 }
 
+/// Parameters for render_mermaid tool
+#[derive(Debug, Serialize, Deserialize, rmcp::schemars::JsonSchema)]
+pub struct RenderMermaidParams {
+    /// The Mermaid diagram code to render
+    pub mermaid_code: String,
+}
+
 /// An extension for automatic data visualization and UI generation
 #[derive(Clone)]
 pub struct AutoVisualiserRouter {
@@ -448,6 +455,7 @@ impl AutoVisualiserRouter {
             - **render_treemap**: Creates interactive treemap visualizations for hierarchical data
             - **render_chord**: Creates interactive chord diagrams for relationship/flow visualization
             - **render_map**: Creates interactive map visualizations with location markers
+            - **render_mermaid**: Creates interactive Mermaid diagrams from Mermaid syntax
             - **show_chart**: Creates interactive line, scatter, or bar charts for data visualization
         "#};
 
@@ -977,6 +985,61 @@ Example:
         .with_audience(vec![Role::User])]))
     }
 
+    /// show a Mermaid diagram from Mermaid syntax
+    #[tool(
+        name = "render_mermaid",
+        description = r#"show a Mermaid diagram from Mermaid syntax
+
+Provide the Mermaid code as a string. Supports flowcharts, sequence diagrams, Gantt charts, etc.
+
+Example:
+graph TD;
+    A-->B;
+    A-->C;
+    B-->D;
+    C-->D;
+"#
+    )]
+    pub async fn render_mermaid(
+        &self,
+        params: Parameters<RenderMermaidParams>,
+    ) -> Result<CallToolResult, ErrorData> {
+        let mermaid_code = params.0.mermaid_code;
+
+        // Load all resources at compile time using include_str!
+        const TEMPLATE: &str = include_str!("templates/mermaid_template.html");
+        const MERMAID_MIN: &str = include_str!("templates/assets/mermaid.min.js");
+
+        // Replace all placeholders with actual content
+        let html_content = TEMPLATE
+            .replace("{{MERMAID_MIN}}", MERMAID_MIN)
+            .replace("{{MERMAID_CODE}}", &mermaid_code);
+
+        // Save to /tmp/mermaid.html for debugging
+        let debug_path = std::path::Path::new("/tmp/mermaid.html");
+        if let Err(e) = std::fs::write(debug_path, &html_content) {
+            tracing::warn!("Failed to write debug HTML to /tmp/mermaid.html: {}", e);
+        } else {
+            tracing::info!("Debug HTML saved to /tmp/mermaid.html");
+        }
+
+        // Use BlobResourceContents with base64 encoding to avoid JSON string escaping issues
+        let html_bytes = html_content.as_bytes();
+        let base64_encoded = STANDARD.encode(html_bytes);
+
+        let resource_contents = ResourceContents::BlobResourceContents {
+            uri: "ui://mermaid/diagram".to_string(),
+            mime_type: Some("text/html".to_string()),
+            blob: base64_encoded,
+            meta: None,
+        };
+
+        Ok(CallToolResult::success(vec![Content::resource(
+            resource_contents,
+        )
+        .with_audience(vec![Role::User])]))
+    }
+
     /// show interactive line, scatter, or bar charts
     #[tool(
         name = "show_chart",
@@ -1472,4 +1535,32 @@ mod tests {
             &vec![Role::User]
         );
     }
+
+    #[tokio::test]
+    async fn test_render_mermaid() {
+        let router = AutoVisualiserRouter::new();
+        let params = Parameters(RenderMermaidParams {
+            mermaid_code: r#"graph TD;
+    A-->B;
+    A-->C;
+    B-->D;
+    C-->D;"#
+                .to_string(),
+        });
+
+        let result = router.render_mermaid(params).await;
+        if let Err(e) = &result {
+            eprintln!("Error in test_render_mermaid: {:?}", e);
+        }
+        assert!(result.is_ok());
+        let tool_result = result.unwrap();
+        assert_eq!(tool_result.content.len(), 1);
+
+        // Check the audience is set to User
+        assert!(tool_result.content[0].audience().is_some());
+        assert_eq!(
+            tool_result.content[0].audience().unwrap(),
+            &vec![Role::User]
+        );
+    }
 }

crates/goose-mcp/src/autovisualiser/templates/mermaid_template.html

@@ -0,0 +1,173 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Mermaid Diagram</title>
+
+    <script>
+        {{MERMAID_MIN}}
+    </script>
+
+    <style>
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
+            margin: 0;
+            padding: 20px;
+            background-color: #f5f5f5;
+            color: #333;
+        }
+
+        .container {
+            max-width: 1200px;
+            margin: 0 auto;
+            background: white;
+            border-radius: 12px;
+            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
+            overflow: hidden;
+            padding: 30px;
+        }
+
+        .header {
+            text-align: center;
+            margin-bottom: 30px;
+        }
+
+        .header h1 {
+            margin: 0 0 10px 0;
+            font-size: 2em;
+            font-weight: 300;
+            color: #333;
+        }
+
+        .mermaid {
+            display: flex;
+            justify-content: center;
+            align-items: center;
+            min-height: 400px;
+        }
+
+        /* Mermaid specific styles */
+        .mermaid .node {
+            fill: #667eea !important;
+            stroke: #4a5fc1 !important;
+            stroke-width: 2px !important;
+        }
+
+        .mermaid .node text {
+            fill: white !important;
+            font-weight: 500 !important;
+        }
+
+        .mermaid .edgePath path {
+            stroke: #667eea !important;
+            stroke-width: 2px !important;
+        }
+
+        .mermaid .edgeLabel text {
+            fill: #333 !important;
+        }
+    </style>
+</head>
+<body>
+    <div class="container">
+        <div class="header">
+            <h1>Mermaid Diagram</h1>
+        </div>
+        <div class="mermaid">
+            {{MERMAID_CODE}}
+        </div>
+    </div>
+
+    <script>
+        // Initialize Mermaid
+        mermaid.initialize({
+            startOnLoad: true,
+            theme: 'default',
+            themeVariables: {
+                primaryColor: '#667eea',
+                primaryTextColor: '#fff',
+                primaryBorderColor: '#4a5fc1',
+                lineColor: '#667eea',
+                sectionBkgColor: '#f8f9fa',
+                altSectionBkgColor: '#e9ecef',
+                gridColor: '#e9ecef',
+                tertiaryColor: '#f8f9fa'
+            },
+            flowchart: {
+                useMaxWidth: true,
+                htmlLabels: true,
+                curve: 'basis'
+            },
+            sequence: {
+                useMaxWidth: true,
+                htmlLabels: true,
+                diagramMarginX: 50,
+                diagramMarginY: 10,
+                actorMargin: 50,
+                width: 150,
+                height: 65,
+                boxMargin: 10,
+                boxTextMargin: 5,
+                noteMargin: 10,
+                messageMargin: 35,
+                mirrorActors: true,
+                bottomMarginAdj: 1,
+                useMaxWidth: true
+            },
+            gantt: {
+                useMaxWidth: true,
+                titleTopMargin: 25,
+                barHeight: 20,
+                barGap: 4,
+                topPadding: 50,
+                leftPadding: 75,
+                gridLineStartPadding: 35,
+                fontSize: 11,
+                fontFamily: '"Open Sans", sans-serif',
+                numberSectionStyles: 4,
+                axisFormat: '%Y-%m-%d'
+            }
+        });
+
+        function reportContentSize() {
+            const contentHeight = Math.max(
+                document.body.scrollHeight,
+                document.body.offsetHeight,
+                document.documentElement.clientHeight,
+                document.documentElement.scrollHeight,
+                document.documentElement.offsetHeight
+            );
+
+            // Send size change message to parent window (for MCP-UI iframe auto-resize)
+            if (window.parent !== window) {
+                window.parent.postMessage({
+                    type: 'ui-size-change',
+                    payload: {
+                        height: contentHeight
+                    }
+                }, '*');
+            }
+        }
+
+        // Initialize on load
+        window.onload = function() {
+            // Report initial size
+            setTimeout(reportContentSize, 100);
+
+            // Watch for size changes using ResizeObserver if available
+            if (typeof ResizeObserver !== 'undefined') {
+                const resizeObserver = new ResizeObserver(() => {
+                    reportContentSize();
+                });
+                resizeObserver.observe(document.body);
+                resizeObserver.observe(document.documentElement);
+            }
+
+            // Fallback: also report on window resize
+            window.addEventListener('resize', reportContentSize);
+        };
+    </script>
+</body>
+</html></content>
+<parameter name="filePath">c:\Users\ARYA SINGH\Dropbox\PC\Desktop\goose\crates\goose-mcp\src\autovisualiser\templates\mermaid_template.html

documentation/docs/mcp/autovisualiser-mcp.md

@@ -61,6 +61,7 @@ The Auto Visualiser is a powerful extension that integrates with Goose's MCP-UI
 | **Treemap Visualizations** | Hierarchical data with proportional area representation | Hierarchical data <br/>(nested categories, organizational structures) |
 | **Chord Diagrams** | Relationship and flow visualization between entities | Relationship matrices <br/>(network connections, cross-references) |
 | **Interactive Maps** | Geographic data visualization with location markers using Leaflet | Geographic information <br/>(location data, coordinates, addresses) |
+| **Mermaid Diagrams** | Flowcharts, sequence diagrams, Gantt charts, and other diagram types using Mermaid syntax | Diagram creation <br/>(flowcharts, sequence diagrams, architecture diagrams) |
 | **Line/Bar/Scatter Charts** | Traditional chart types for data analysis | Time series data <br/>(historical data, trends over time) |
 
 ### Example Visualizations