Diagram Generator

AI-powered diagram creation, editing, and format conversion. Generate flowcharts, sequence diagrams, ER diagrams, architecture diagrams and more in Mermaid, draw.io, PlantUML, and Graphviz formats. Powered by evolink.ai

AI-powered diagram creation, editing, and format conversion from your terminal. Generate flowcharts, sequence diagrams, ER diagrams, architecture diagrams and more in Mermaid, draw.io, PlantUML, and Graphviz formats.

Powered by Evolink.ai

When to Use

• User wants to generate a diagram from a natural language description
• User asks to modify or update an existing diagram file
• User needs to convert a diagram between formats (e.g., Mermaid to draw.io)
• User wants to understand what an existing diagram represents
• User asks to preview or render a diagram locally
• User needs a quick reference for diagram types and format syntax

Quick Start

1. Set your EvoLink API key

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export EVOLINK_API_KEY="your-key-here"

Get a free key: evolink.ai/signup

2. Generate a diagram

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bash scripts/diagram.sh generate flowchart "user login flow with OAuth and MFA"

3. Preview it

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bash scripts/diagram.sh preview login_diagram.mmd

Capabilities

Local Commands (no API key needed)

Command	Description
templates	List all diagram types, formats, and usage examples
preview <file>	Open diagram in browser (Mermaid HTML, draw.io link, PlantUML URL, Graphviz SVG)

AI Commands (require EVOLINK_API_KEY)

Command	Description
generate <type> [--format <fmt>] "<desc>"	AI generate diagram from natural language description
edit <file> "<instruction>"	AI modify existing diagram file based on instruction
convert <file> --to <format>	AI convert diagram between formats
explain <file>	AI explain diagram structure in plain language

Diagram Types

Type	Description
flowchart	Process flows, decision trees, workflows
sequence	API calls, service interactions, message flows
class	OOP class hierarchies, interfaces, relationships
er	Database entity-relationship diagrams
state	State machines, lifecycle transitions
mindmap	Idea maps, topic hierarchies, brainstorming
architecture	System architecture, microservices, cloud infra
network	Network topology, server layout, connectivity
gantt	Project timelines, task scheduling
pie	Data distribution, proportions
git	Git branch/merge visualization
c4	C4 model (context, container, component, code)

Output Formats

Format	Extension	Best For
mermaid	.mmd	Documentation, README files (native GitHub/GitLab rendering)
drawio	.drawio	Architecture diagrams (drag-and-drop editing in diagrams.net)
plantuml	.puml	UML diagrams (rich UML support, sequence diagrams)
graphviz	.dot	Graph/network layouts (automatic layout algorithms)

Examples

Generate a flowchart

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bash scripts/diagram.sh generate flowchart "CI/CD pipeline with build, test, and deploy stages"

Generate an ER diagram in draw.io format

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bash scripts/diagram.sh generate er --format drawio "e-commerce database with users, orders, products"

Edit an existing diagram

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bash scripts/diagram.sh edit flow.mmd "add error handling branch after validation step"

Convert Mermaid to draw.io

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bash scripts/diagram.sh convert flow.mmd --to drawio

Explain a diagram

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bash scripts/diagram.sh explain architecture.puml

Preview a Mermaid diagram

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bash scripts/diagram.sh preview flow.mmd

Configuration

Variable	Default	Required	Description
EVOLINK_API_KEY	—	Yes (AI commands)	Your EvoLink API key. Get one free
EVOLINK_MODEL	claude-opus-4-6	No	Model for AI generation

Required binaries: python3, curl

Optional: dot (Graphviz) for local SVG rendering in preview command

Security

Data Transmission

AI commands send diagram content to api.evolink.ai for processing by Claude. By setting EVOLINK_API_KEY and using these commands, you consent to this transmission. Data is not stored after the response is returned. The templates and preview commands run entirely locally and never transmit data.

Preview Command

• Mermaid preview generates a local HTML file using the Mermaid.js CDN — no diagram data is sent externally.
• PlantUML preview sends diagram code to plantuml.com for rendering. A warning is displayed before opening.
• draw.io preview opens the diagrams.net web app — you load the file manually.
• Graphviz preview renders locally via the dot binary if installed.

Network Access

• api.evolink.ai — AI generation (AI commands only)
• cdn.jsdelivr.net — Mermaid.js library (preview command, Mermaid format only)
• plantuml.com — PlantUML rendering (preview command, PlantUML format only)

Persistence & Privilege

Temporary files for API payloads are cleaned up automatically. No credentials or persistent data are stored.

Links

• GitHub
• EvoLink API
• Community
• Support