Skip to main content
Glama

Fast Mermaid Validator MCP

by ai-of-mine
npmGitHub
JavaScript
Apache 2.0
134
2
OverviewInspectNewEndpointsSchemaRelated ServersReviewsScore
Need Help?View Source CodeReport Issue

Mermaid Validator API

License Version Node.js Docker Open Source

High-performance API and Model Context Protocol (MCP) server for validating Mermaid diagrams with comprehensive security features, multiple transport options, and enterprise-grade capabilities.

Author: Gregorio Elias Roecker Momm (gregoriomomm@gmail.com)

🆕 Latest Updates (v1.0.29)

Unified CLI with Port Configuration:

  • ✅ Single Command: One npx command with flags to start any server mode

  • ✅ Port Control: --port <number> flag works with all server modes

  • ✅ Environment Variables: PORT, MCP_HTTP_PORT, MCP_HTTP_HOST support

  • ✅ REST API: npx @ai-of-mine/fast-mermaid-validator-mcp (default port: 8000)

  • ✅ MCP HTTP: npx @ai-of-mine/fast-mermaid-validator-mcp --mcp-http (default port: 8080)

  • ✅ Built-in Help: npx @ai-of-mine/fast-mermaid-validator-mcp --help

Package Features:

  • ✅ NPM Package: Available as @ai-of-mine/fast-mermaid-validator-mcp

  • ✅ Security Updates: Fixed multer vulnerabilities

  • ✅ Clean Logging: Default log level set to warn for production readiness

  • ✅ Complete Distribution: Both source (src/) and compiled (dist/mcp/) files

  • ✅ Enterprise Ready: Unlimited configuration, environment variables, Docker support

API Endpoints:

  • http://localhost:8000/api/v1/validate - Direct diagram validation (JSON)

  • http://localhost:8000/api/v1/upload/file - File upload validation (multipart)

MCP Server Commands:

  • npx @ai-of-mine/fast-mermaid-validator-mcp --mcp-stdio - Stdio transport (Claude Desktop)

  • npx @ai-of-mine/fast-mermaid-validator-mcp --mcp-http - HTTP transport (port 8080)

  • npx @ai-of-mine/fast-mermaid-validator-mcp --mcp-secure - Secure HTTP with authentication

🚀 Dual Architecture: REST API + MCP Server

This project provides two complementary interfaces:

  1. 🌐 REST API: Traditional HTTP API for web applications and direct integrations

  2. 🤖 MCP Server: Model Context Protocol server for LLM integrations (Claude Desktop, etc.)

Quick Start

# Install from npm (recommended) npm install @ai-of-mine/fast-mermaid-validator-mcp # Start REST API server (default) npx @ai-of-mine/fast-mermaid-validator-mcp # Start MCP HTTP server npx @ai-of-mine/fast-mermaid-validator-mcp --mcp-http # Start MCP stdio server npx @ai-of-mine/fast-mermaid-validator-mcp --mcp-stdio # Start MCP secure server npx @ai-of-mine/fast-mermaid-validator-mcp --mcp-secure # Show help npx @ai-of-mine/fast-mermaid-validator-mcp --help

Alternative: Install from source

git clone https://github.com/ai-of-mine/fast-mermaid-validator-mcp.git cd mermaid-validator-mcp npm install npm run build:mcp # Use npm scripts npm start # REST API server npm run start:mcp # MCP stdio npm run start:mcp-http # MCP HTTP npm run start:mcp-secure # MCP secure

Test MCP HTTP server:

npx @modelcontextprotocol/inspector http://localhost:8080/mcp

alt text

🎯 Core Features

Validation Capabilities

  • 28 Mermaid Diagram Types: Complete support with real grammar parsing

  • Multi-format Support: Markdown files, ZIP archives, direct input

  • Real Grammar Validation: Jison, ANTLR, and Langium parsers

  • High Performance: Optimized with minimal dependencies

MCP Server Features

  • Multiple Transports: Stdio, HTTP streamable, Server-Sent Events (SSE)

  • 3 MCP Tools: validate-diagrams, validate-files, get-validation-stats

  • 2 MCP Resources: config://limits, info://diagram-types

  • Full Protocol Compliance: JSON-RPC 2.0, MCP specification 2024-11-05

Security & Enterprise

  • Security Compliant: Complete audit logging and security best practices

  • Authentication: API key and Bearer token support

  • Rate Limiting: Configurable request throttling

  • Input Validation: Comprehensive sanitization and validation

  • Container Ready: Docker deployment with optimized images

Supported Diagram Types (28 Total)

Jison-based Validation (23 types)

  • Flowchart: flowchart, graph - Flow diagrams and process charts ✅

  • Sequence: sequenceDiagram - UML sequence diagrams ✅

  • Class: classDiagram - UML class diagrams ✅

  • State: stateDiagram, stateDiagram-v2 - UML state diagrams ✅

  • ER: erDiagram - Entity relationship diagrams ✅

  • Gantt: gantt - Project timeline charts ✅

  • User Journey: journey - User experience journey maps ✅

  • Requirement: requirement, requirementDiagram - Requirements engineering diagrams ✅

  • Sankey: sankey-beta - Sankey flow diagrams ✅

  • XY Chart: xychart-beta - Line and bar charts ✅

  • Kanban: kanban - Kanban boards ✅

  • Block: block, block-beta - Block diagrams ✅

  • C4: c4, C4Context - C4 architecture diagrams ✅

  • Mindmap: mindmap - Mind maps ✅

  • Quadrant: quadrant, quadrantChart - Four-quadrant charts ✅

  • Timeline: timeline - Timeline diagrams ✅

  • Example: exampleDiagram - Example/test diagrams ✅

Langium-based Validation (5 types)

  • Packet: packet, packet-beta - Packet diagrams ✅

  • Architecture: architecture, architecture-beta - Architecture diagrams ✅

  • Treemap: treemap - Treemap diagrams ✅

Validation Results: 28/28 types supported with real grammar parsing

🤖 MCP Server Documentation

For complete MCP server documentation, see: docs/api/README-MCP.md

Quick MCP Commands

# Stdio transport (for Claude Desktop) npm run start:mcp # HTTP streamable transport (for web integrations) npm run start:mcp-http # Secure transport (production ready) npm run start:mcp-secure # Test with MCP Inspector npx @modelcontextprotocol/inspector http://localhost:8080/mcp

MCP Tools Available

  • validate_mermaid: Direct diagram validation with comprehensive error reporting

  • validate_file: File content validation (Markdown, ZIP support) with base64 encoding

  • get_examples: Get sample diagrams for all 28+ supported diagram types

MCP Resources Available

  • config://limits: Validation limits and configuration

  • info://diagram-types: All 28 supported diagram types

🛠️ Claude Code Integration

Adding to Claude Code

  1. Install and start the MCP server:

    # Install from npm npm install @ai-of-mine/fast-mermaid-validator-mcp # Or from source git clone https://github.com/ai-of-mine/fast-mermaid-validator-mcp.git cd mermaid-validator-mcp npm install npm run build:mcp npm run start:mcp-http # HTTP transport for Claude Code

  2. Configure Claude Code using the CLI:

    claude mcp add --transport http -s project mermaid-validator http://localhost:8080/mcp

    This creates a .mcp.json file in your project:

    { "mcpServers": { "mermaid-validator": { "type": "http", "url": "http://localhost:8080/mcp" } } }

  3. Available Tools in Claude Code:

    🔍 validate_file - Validate ZIP Archives and Markdown Files

    Process Base64-encoded ZIP archives containing multiple markdown files, or individual markdown files. Automatically extracts ZIP contents, finds ```mermaid code blocks, and validates all diagrams. Perfect for: Documentation validation, CI/CD checks, bulk processing

    🔧 validate_mermaid - Validate Individual Mermaid Diagrams

    Validate raw Mermaid diagram code blocks directly. Supports all 28+ diagram types with detailed syntax checking. Returns comprehensive error information with line numbers. Perfect for: Single diagram validation, syntax checking, error debugging

    📊 get_examples - Get Sample Diagrams

    Retrieve sample Mermaid diagrams for all supported diagram types. Perfect for learning syntax, testing validation, and development.

Usage Examples with Claude Code

Validate a documentation repository:

Use the validate_file tool with this ZIP file containing our documentation: [Upload ZIP file with multiple .md files]

Check a single diagram:

Use validate_mermaid to check this flowchart: flowchart TD A[Start] --> B{Decision} B -->|Yes| C[Action 1] B -->|No| D[Action 2]

Get sample diagrams:

Use get_examples to show sample diagrams for all supported types

Developer Workflow Example:

1. "Show me examples of flowchart diagrams" 2. "Validate this sequence diagram: [paste diagram]" 3. "Check all diagrams in this documentation folder: [upload ZIP]" 4. "Fix the syntax errors you found and re-validate"

Supported Integrations

  • ✅ Claude Code (HTTP transport)

  • ✅ MCP Inspector (SSE/HTTP)

  • ✅ Claude Desktop (stdio transport)

  • ✅ Custom MCP clients (all transports)

🌐 REST API Documentation

Quick Start

Start the API server:

npx @ai-of-mine/fast-mermaid-validator-mcp

The server runs on http://localhost:8000 by default.

API Endpoints

1. Direct Diagram Validation

POST /api/v1/validate Content-Type: application/json

Examples:

Valid Flowchart:

curl -X POST http://localhost:8000/api/v1/validate \ -H "Content-Type: application/json" \ -d '{ "diagram": "flowchart TD\n A[Start] --> B[Process]\n B --> C[End]" }'

Invalid Flowchart:

curl -X POST http://localhost:8000/api/v1/validate \ -H "Content-Type: application/json" \ -d '{ "diagram": "flowchart TD\n A[Start -->> B[Invalid]" }'

Valid Sequence Diagram:

curl -X POST http://localhost:8000/api/v1/validate \ -H "Content-Type: application/json" \ -d '{ "diagram": "sequenceDiagram\n Alice->>Bob: Hello\n Bob-->>Alice: Hi there" }'

2. File Upload Validation

POST /api/v1/upload/file Content-Type: multipart/form-data

Parameters:

  • file: One or multiple markdown files (.md, .markdown, .txt) or ZIP archives (.zip)

  • timeout: Optional timeout in milliseconds

Examples:

Single File Upload:

curl -X POST http://localhost:8000/api/v1/upload/file \ -F "file=@diagram.md"

Multiple Files Upload:

curl -X POST http://localhost:8000/api/v1/upload/file \ -F "file=@diagram1.md" \ -F "file=@diagram2.md" \ -F "file=@diagram3.md"

Upload ZIP Archive:

curl -X POST http://localhost:8000/api/v1/upload/file \ -F "file=@diagrams.zip"

With Validation Timeout:

curl -X POST http://localhost:8000/api/v1/upload/file \ -F "file=@diagram.md" \ -F "timeout=60000"

Response:

{ "requestId": "db4d2fd2-d16c-42b5-b09f-a4e67408ea06", "timestamp": "2025-09-12T00:40:02.595Z", "processingTime": 2, "validator": "custom_grammar_parser", "totalFiles": 1, "processedFiles": 1, "totalDiagrams": 1, "validDiagrams": 0, "invalidDiagrams": 1, "fileProcessing": { "totalFiles": 1, "processedFiles": 1, "errors": [], "processingTime": 1 }, "files": [ { "fileName": "sequence_test.md", "size": 152, "totalDiagrams": 1, "validDiagrams": 0, "invalidDiagrams": 1, "results": [ { "diagramId": "diagram_1", "valid": false, "errors": [ { "type": "syntax_error", "message": "Parse error on line 2: Expecting 'TEXT', got 'ID'", "line": 2, "column": 1 } ], "warnings": [], "metadata": { "diagramType": "sequenceDiagram", "validationMethod": "real_jison_grammar", "contentLength": 112, "lineCount": 5, "processingTime": 1 } } ], "errors": [] } ], "validationOptions": { "timeout": 30000 } }

Multiple Files Upload:

curl -X POST http://localhost:8000/api/v1/upload/file \ -F "file=@valid_diagrams.md" \ -F "file=@invalid_diagrams.md"

Response:

{ "requestId": "f47ac10b-58cc-4372-a567-0e02b2c3d479", "timestamp": "2025-09-12T00:40:05.123Z", "processingTime": 15, "validator": "custom_grammar_parser", "totalFiles": 2, "processedFiles": 2, "totalDiagrams": 5, "validDiagrams": 3, "invalidDiagrams": 2, "fileProcessing": { "totalFiles": 2, "processedFiles": 2, "errors": [], "processingTime": 8 }, "files": [ { "fileName": "valid_diagrams.md", "size": 456, "totalDiagrams": 3, "validDiagrams": 3, "invalidDiagrams": 0, "results": [ { "diagramId": "diagram_1", "valid": true, "errors": [], "warnings": [], "metadata": { "diagramType": "flowchart", "validationMethod": "real_jison_grammar", "contentLength": 45, "lineCount": 3, "processingTime": 2 } } ], "errors": [] }, { "fileName": "invalid_diagrams.md", "size": 234, "totalDiagrams": 2, "validDiagrams": 0, "invalidDiagrams": 2, "results": [ { "diagramId": "diagram_1", "valid": false, "errors": [ { "type": "syntax_error", "message": "Parse error: Invalid syntax on line 1", "line": 1 } ], "metadata": { "diagramType": "flowchart", "validationMethod": "real_jison_grammar" } } ], "errors": [] } ], "validationOptions": { "timeout": 30000 } }

ZIP Archive Upload:

curl -X POST http://localhost:8000/api/v1/upload/file \ -F "file=@diagrams.zip;type=application/zip"

Response:

{ "requestId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890", "timestamp": "2025-09-12T00:40:10.456Z", "processingTime": 25, "validator": "custom_grammar_parser", "totalFiles": 1, "processedFiles": 1, "totalDiagrams": 8, "validDiagrams": 6, "invalidDiagrams": 2, "fileProcessing": { "totalFiles": 1, "processedFiles": 1, "errors": [], "processingTime": 12 }, "files": [ { "fileName": "diagrams.zip", "size": 2048, "totalDiagrams": 8, "validDiagrams": 6, "invalidDiagrams": 2, "results": [ { "diagramId": "diagram_1", "valid": true, "errors": [], "metadata": { "diagramType": "flowchart", "sourceFile": "diagrams.zip/flowchart.md", "validationMethod": "real_jison_grammar" } }, { "diagramId": "diagram_2", "valid": true, "errors": [], "metadata": { "diagramType": "sequenceDiagram", "sourceFile": "diagrams.zip/sequence.md", "validationMethod": "real_jison_grammar" } } ], "errors": [] } ] }

Error Response Example:

{ "error": "File validation failed", "message": "File size exceeds maximum allowed (10MB)", "requestId": "error-123-456", "timestamp": "2025-09-12T00:40:15.789Z" }

Test Results - All 25 Diagram Types:

# Comprehensive test with all supported diagram types curl -X POST http://localhost:8000/api/v1/validate \ -H "Content-Type: application/json" \ -d '{"diagrams": [ {"content": "flowchart TD\n A[Start] --> B[Process]\n B --> C[End]", "type": "flowchart"}, {"content": "sequenceDiagram\n participant A\n participant B\n A->>B: Hello", "type": "sequenceDiagram"}, {"content": "classDiagram\n class Animal\n Animal : +name string", "type": "classDiagram"}, {"content": "stateDiagram-v2\n [*] --> Still\n Still --> [*]", "type": "stateDiagram-v2"}, {"content": "erDiagram\n CUSTOMER {\n string name\n }", "type": "erDiagram"}, {"content": "gantt\n title A Gantt\n dateFormat YYYY-MM-DD\n section Section\n A task: 2014-01-01, 30d", "type": "gantt"}, {"content": "journey\n title My day\n section Go to work\n Make tea: 5: Me", "type": "journey"}, {"content": "requirementDiagram\n requirement test_req {\n id: 1\n text: test\n }", "type": "requirement"}, {"content": "xychart-beta\n title Sales\n x-axis [jan, feb]\n bar [5000, 6000]", "type": "xychart-beta"}, {"content": "kanban\n Todo\n Task 1\n Done\n Task 2", "type": "kanban"}, {"content": "C4Context\n Person(user, \"User\")", "type": "c4"}, {"content": "mindmap\n root((idea))\n branch1\n branch2", "type": "mindmap"}, {"content": "quadrantChart\n title Chart\n x-axis Low --> High\n quadrant-1 Expand", "type": "quadrant"}, {"content": "timeline\n title History\n 2020 : Event 1\n 2021 : Event 2", "type": "timeline"}, {"content": "pie title Data\n \"A\" : 50\n \"B\" : 30", "type": "pie"}, {"content": "gitGraph\n commit\n commit\n branch dev\n commit", "type": "gitGraph"}, {"content": "info\n showInfo", "type": "info"}, {"content": "architecture-beta\n service db(database)[DB]", "type": "architecture"}, {"content": "radar\n title Analysis\n \"Metric\" : [8, 6]", "type": "radar"}, {"content": "packet-beta\n 0-15: Source Port", "type": "packet"}, {"content": "treemap-beta\n title Tree\n Branch\n Leaf: 100", "type": "treemap"} ]}' # Result: 21/23 diagrams validated successfully # ✅ All Jison parsers working (18 types) # ✅ All Langium parsers working (7 types) # ❌ 2 expected syntax failures in test data

Health Check

GET /api/v1/health

Response:

{ "status": "healthy", "timestamp": "2025-09-13T02:40:00.000Z", "uptime": 3600.5, "version": "1.0.15", "environment": "production" }

Direct Validation (Alternative Method)

POST /api/v1/validate Content-Type: application/json

Request:

{ "diagrams": [ { "content": "flowchart TD\\n A --> B", "type": "flowchart" }, { "content": "pie title Sample\\n \"A\" : 50\\n \"B\" : 30", "type": "pie" } ], "options": { "generateSvg": false, "timeout": 30000 } }

Response:

{ "requestId": "6e7ffdb8-b023-4c6b-8576-1cc60229c381", "timestamp": "2025-09-11T06:21:45.793Z", "totalDiagrams": 2, "validDiagrams": 2, "invalidDiagrams": 0, "processingTime": 33, "validator": "custom_grammar_parser", "results": [ { "diagramId": "direct_1", "valid": true, "errors": [], "warnings": [], "metadata": { "diagramType": "flowchart", "validationMethod": "real_jison_grammar", "contentLength": 25, "lineCount": 2, "processingTime": 3, "customValidator": true } }, { "diagramId": "direct_2", "valid": true, "errors": [], "warnings": [], "metadata": { "diagramType": "pie", "validationMethod": "langium_grammar", "contentLength": 35, "lineCount": 3, "processingTime": 1, "customValidator": true } } ] }

Validation Statistics

GET /api/v1/validate/stats

Response:

{ "supportedDiagramTypes": [ "flowchart", "graph", "sequenceDiagram", "classDiagram", "stateDiagram", "stateDiagram-v2", "erDiagram", "gantt", "journey", "requirement", "sankey-beta", "xychart-beta", "kanban", "block", "c4", "mindmap", "quadrant", "timeline", "pie", "gitGraph", "info", "architecture", "radar", "packet", "treemap" ], "validationMethods": { "jison": 18, "langium": 7, "total": 25 }, "limits": { "maxFileSize": 10485760, "maxFiles": 20, "maxDiagramsPerFile": 50, "maxTotalDiagrams": 200, "validationTimeout": 30000 }, "features": { "realGrammarValidation": true, "markdownSupport": true, "multiFileValidation": true, "diagramGrammarParsers": true, "jisonParsers": true, "langiumParsers": true } }

🚀 Quick Start

Using Docker (Recommended)

# Pull and run the container docker run -p 8000:8000 mermaid-validator-mcp # Or build from source git clone <repository> cd mermaid-validator-mcp docker-compose up

Using Node.js

# Install from npm npm install @ai-of-mine/fast-mermaid-validator-mcp # Or install development dependencies from source git clone https://github.com/ai-of-mine/fast-mermaid-validator-mcp.git cd mermaid-validator-mcp npm install # Start development server npm run dev # Start production server npm start

Environment Variables

🆕 New Configurable Limits (v1.0.15)

# Server Configuration PORT=8000 HOST=0.0.0.0 NODE_ENV=production # Server Performance Optimization SERVER_TIMEOUT=30000 # Server timeout in milliseconds KEEP_ALIVE_TIMEOUT=5000 # Keep-alive timeout HEADERS_TIMEOUT=6000 # Headers timeout (must be > keep-alive) MAX_CONNECTIONS=1000 # Maximum concurrent connections MAX_HEADERS_COUNT=2000 # Maximum headers per request MAX_REQUESTS_PER_SOCKET=0 # Max requests per socket (0 = unlimited) # Security (Rate limiting delegated to API Gateway) CORS_ORIGIN=* HSTS_MAX_AGE=31536000 # HTTPS Strict Transport Security # File Upload Limits (All configurable, use -1 for unlimited) MAX_FILE_SIZE=104857600 # 100MB (was 10MB) MAX_FILES=100000 # 100k files (was 20) MAX_TOTAL_DIAGRAMS=1000000 # 1M diagrams (was 200) MAX_DIAGRAMS_PER_FILE=10000 # 10k per file (was 50) # Validation Limits (All configurable, use -1 for unlimited) VALIDATION_TIMEOUT=30000 MAX_DIAGRAM_CONTENT_LENGTH=1048576 # 1MB per diagram (was 50KB) MAX_TIMEOUT_MS=60000 # Max validation timeout MAX_FILENAME_LENGTH=255 # Max filename length # Mermaid Parser Limits (All configurable, use -1 for unlimited) MERMAID_MAX_TEXT_SIZE=1048576 # 1MB (was 50KB) MERMAID_MAX_EDGES=10000 # 10k edges (was 500) MERMAID_MAX_VERTICES=5000 # 5k vertices (was 200) # Logging LOG_LEVEL=info LOG_TO_FILE=true LOG_FILE=logs/app.log LOG_MAX_FILES=5 LOG_MAX_SIZE=10m # Health Monitoring MEMORY_THRESHOLD=90 DISK_THRESHOLD=90 # Cleanup TEMP_DIR=./tmp CLEANUP_INTERVAL=3600000 # 1 hour cleanup interval

🚀 Unlimited Mode

Set any limit to -1 to disable it completely:

# Unlimited processing configuration MAX_FILES=-1 # Process unlimited files MAX_FILE_SIZE=-1 # Accept any file size MAX_DIAGRAM_CONTENT_LENGTH=-1 # Process any diagram size MERMAID_MAX_TEXT_SIZE=-1 # No text size limits MERMAID_MAX_EDGES=-1 # No edge count limits MERMAID_MAX_VERTICES=-1 # No vertex count limits

📋 See

Deployment

Prerequisites

  • Kubernetes cluster with kubectl access

  • Container registry access (Docker Hub, GitHub Container Registry, etc.)

  • Docker/Podman for building images

  • Helm 3.x (for Helm deployments)

Make Commands

Development

make install # Install dependencies make dev # Start development server make test # Run tests make lint # Code linting make security # Security checks

Build & Deploy

make deployment-amd64 # Build AMD64 deployment make deployment-arm64 # Build ARM64 deployment (local) make push-amd64 # Push AMD64 to registry make push-arm64 # Push ARM64 to registry

Kubernetes (Kustomize)

make k8s-deploy-dev # Deploy to mmjc-dev namespace make k8s-deploy-test # Deploy to mmjc-test namespace make k8s-status-dev # Check dev deployment status make k8s-status-test # Check test deployment status make k8s-logs-dev # View dev logs make k8s-logs-test # View test logs

Kubernetes (Helm)

make helm-install-dev # Install Helm chart (dev) make helm-install-test # Install Helm chart (test) make helm-uninstall-dev # Uninstall Helm chart (dev) make helm-uninstall-test # Uninstall Helm chart (test)

Docker Development

docker-compose --profile dev up

Production Deployment

docker-compose --profile production up

With Monitoring

docker-compose --profile monitoring up

Environment Configuration

Variable

Description

Default

NODE_ENV

Application environment

production

PORT

Server port

8000

LOG_LEVEL

Logging level

info

See DEPLOYMENT.md for comprehensive deployment instructions.

Monitoring

Health Endpoints

  • GET /api/v1/health - Basic health check

  • GET /api/v1/health/detailed - Detailed system information

  • GET /api/v1/health/live - Kubernetes liveness probe

  • GET /api/v1/health/ready - Kubernetes readiness probe

Metrics (with Prometheus)

  • Request rate and response times

  • Error rates by endpoint

  • Memory and CPU usage

  • File processing statistics

  • Validation success/failure rates

Grafana Dashboards

  • API performance metrics

  • System resource utilization

  • Error rate monitoring

  • Request volume trends

Security Features

  • Rate Limiting: Configurable per-IP request limits (100 requests per 15 minutes)

  • Input Validation: Comprehensive request validation with express-validator

  • File Security: Dual MIME type and file extension validation for robust upload security

  • Content Security: CSP headers, XSS protection, and security headers via Helmet

  • CORS Protection: Configurable cross-origin policies with whitelist support

  • Process Security: Non-root container execution with dedicated nodejs user

  • Resource Limits: Memory and disk usage monitoring with configurable thresholds

  • Upload Protection: File size limits, suspicious filename detection, and malware prevention

Testing

# Run all tests npm test # Run with coverage npm run test:coverage # Run in watch mode npm run test:watch # Lint code npm run lint

API Documentation

Interactive API documentation is available at /docs when running in development mode.

Performance

  • Custom Grammar Parser: Fast validation without browser dependencies

  • Concurrent Processing: Multiple diagrams processed in parallel

  • Memory Efficient: Automatic cleanup of temporary files

  • Minimal Dependencies: Reduced attack surface and faster startup

  • Response Compression: Built-in compression for faster responses

Configuration

See src/config/config.js for all available configuration options. Most settings can be controlled via environment variables for easy deployment customization.

📋 Claude Code Usage Examples

For comprehensive examples of using this validator with Claude Code, see:

Validation Results Summary

Recent validation of the examples/ folder:

  • Total Files Processed: 9

  • Total Diagrams Found: 43

  • Valid Diagrams: 32 (74% success rate)

  • Invalid Diagrams: 11

Common Issues and Fixes

1. Quoted Text in Node Labels

# ❌ Invalid (causes parser error) flowchart TD A --> B[Error: "No COMMAREA Received"] # ✅ Fixed (remove quotes) flowchart TD A --> B[Error: No COMMAREA Received]

2. Diagram Type Syntax

# ❌ Invalid quadrant title Chart # ✅ Fixed quadrantChart title Chart

3. Beta Suffix Requirements

# ❌ Invalid treemap title Tree # ✅ Fixed treemap-beta title Tree

Developer Workflow with Latest Features

  1. Discovery: claude validate all diagrams in examples folder

  2. Batch Processing: Validates 43 diagrams across 9 files with unlimited processing

  3. Error Analysis: Comprehensive error reporting with line numbers and context

  4. Systematic Fixes: Apply corrections based on detailed error messages

  5. Re-validation: Instant re-validation with optimized performance

  6. Enterprise Scale: Process 100MB files, 100k+ diagrams with zero limits

Performance Capabilities (v1.0.15)

  • Single Pod: 500+ concurrent connections (with nginx proxy)

  • Cluster Scale: Auto-scale to 10,000+ concurrent connections

  • Processing: 145 req/sec sustained throughput

  • Zero-Error Experience: Aggressive HPA prevents connection failures

  • Enterprise Limits: 100MB files, 1MB diagrams, unlimited processing

License

PROPRIETARY - see LICENSE file for details.

Author

Gregorio Elias Roecker Momm

This server cannot be installed

-
security - not tested
F
license - not found
-
quality - not tested

How are these scores calculated?

hybrid server

The server is able to function both locally and remotely, depending on the configuration or use case.

Validates Mermaid diagrams with comprehensive grammar parsing supporting 28+ diagram types. Processes markdown files, ZIP archives, and direct input with detailed error reporting and enterprise-grade performance capabilities.

  1. 🆕 Latest Updates (v1.0.29)
    1. 🚀 Dual Architecture: REST API + MCP Server
      1. Quick Start
    2. 🎯 Core Features
      1. Validation Capabilities
      2. MCP Server Features
      3. Security & Enterprise
    3. Supported Diagram Types (28 Total)
      1. Jison-based Validation (23 types)
      2. Langium-based Validation (5 types)
    4. 🤖 MCP Server Documentation
      1. Quick MCP Commands
      2. MCP Tools Available
      3. MCP Resources Available
    5. 🛠️ Claude Code Integration
      1. Adding to Claude Code
      2. Usage Examples with Claude Code
      3. Supported Integrations
    6. 🌐 REST API Documentation
      1. Quick Start
    7. API Endpoints
      1. 1. Direct Diagram Validation
      2. 2. File Upload Validation
      3. Health Check
      4. Direct Validation (Alternative Method)
      5. Validation Statistics
    8. 🚀 Quick Start
      1. Using Docker (Recommended)
      2. Using Node.js
      3. Environment Variables
      4. 🆕 New Configurable Limits (v1.0.15)
      5. 🚀 Unlimited Mode
    9. Deployment
      1. Prerequisites
      2. Make Commands
      3. Docker Development
      4. Production Deployment
      5. With Monitoring
      6. Environment Configuration
    10. Monitoring
      1. Health Endpoints
      2. Metrics (with Prometheus)
      3. Grafana Dashboards
    11. Security Features
      1. Testing
        1. API Documentation
          1. Performance
            1. Configuration
              1. 📋 Claude Code Usage Examples
                1. Validation Results Summary
                2. Common Issues and Fixes
                3. Developer Workflow with Latest Features
                4. Performance Capabilities (v1.0.15)
              2. License
                1. Author

                  New MCP Servers

                  MCP directory API

                  We provide all the information about MCP servers via our MCP API.

                  curl -X GET 'https://glama.ai/api/mcp/v1/servers/ai-of-mine/fast-mermaid-validator-mcp'

                  If you have feedback or need assistance with the MCP directory API, please join our Discord server