subagent

diagram-architect — Claude Code subagent: install and use

Q: How do I install diagram-architect in Claude Code?

Run `npx claude-code-templates@latest --agent documentation/diagram-architect`, then use `.claude/agents/diagram-architect.md`.

This subagent turns code or plain-language requirements into technical diagrams, including flowcharts, ERDs, state machines, and dependency graphs.

Install into Claude Code · claude-code-templates All methods and platforms ↓

npx claude-code-templates@latest --agent documentation/diagram-architect

Open on GitHub

What diagram-architect does

diagram-architect creates diagrams for system architecture, data flows, object states, database schemas, and API interactions. It can inspect a codebase or work from a written description, then produce ASCII, Mermaid, PlantUML, or Draw.io output.

The subagent has access to Read, Write, Edit, and Bash. Use Mermaid for Markdown documentation, ASCII for terminals and code comments, PlantUML for more involved diagrams, or Draw.io when the result needs visual editing. It can also convert a diagram to another format and split a large scheme into overview and detail views.

PlantUML output requires a PlantUML server. Check that dependency before asking the subagent to produce PlantUML diagrams.

What it helps with

map a process with decisions and error paths
generate an ERD from SQL or schema.prisma
show the order of API calls between components
model an object lifecycle or authentication flow
trace imports and draw module dependencies

Example prompts for the agent

Create a Mermaid flowchart for user authentication with MFA.
Generate an ERD from schema.prisma and include the entity relationships.
Map the dependencies in src/services/ from its import statements.

How to install diagram-architect

1claude-code-templates

npx claude-code-templates@latest --agent documentation/diagram-architect

2Manually: put the files in place

.claude/agents/diagram-architect.md

For all projects use ~/.claude/agents/. Claude delegates by the description field or an @-mention

Manually: put the files in place

.codex/agents/diagram-architect.toml

Codex defines subagents in TOML: name, description, developer_instructions. Move the Markdown text into developer_instructions by hand. For all projects use ~/.codex/agents/

Manually: put the files in place

.cursor/agents/diagram-architect.md

Cursor also reads .claude/agents/

Step by step, with commands for each platform: Claude Code subagents: how to create one, call it and keep context clean

Questions about diagram-architect

How do I install diagram-architect in Claude Code?

Run npx claude-code-templates@latest --agent documentation/diagram-architect, then use .claude/agents/diagram-architect.md.

What does diagram-architect do?

It creates ASCII, Mermaid, PlantUML, and Draw.io diagrams from a description or code analysis. Its documented uses include architecture views, ERDs, flowcharts, state machines, and dependency graphs.

What is required for PlantUML diagrams?

PlantUML diagrams require a PlantUML server. Mermaid works well for Markdown documentation, while Draw.io is intended for diagrams that need visual editing.

Similar subagents

All subagents for Writing and docs →

prompt-engineer VoltAgent Community This subagent designs, tests, and improves prompts for LLM production systems. Use it when prompts need evaluation, metrics, or cost tracking. 16,078installs context-manager VoltAgent Community Organizes shared context for multi-agent projects in files, including state, task history, and decisions. Use it when agents need a clear shared workspace. 10,638installs code-explorer official Anthropic This subagent traces existing features from entry points to data storage, mapping the code paths and architecture. Use it before extending unfamiliar code. 1,172installs search-specialist Seth Hobson A web research subagent that filters sources and cross-checks facts. Use it for deep research, competitive analysis, and trend work. CX Codex 6,886installs api-documenter VoltAgent Community Drafts OpenAPI 3.1 specs, code examples, and integration guides for REST or GraphQL APIs. Helpful when documenting endpoints and standardizing schemas. 6,451installs technical-writer VoltAgent Community This subagent creates and maintains API references, user guides, and SDK docs. Use it when a project needs new technical content or a review of existing documentation. 4,345installs

From the same set238

The whole set →

terraform-specialist A Terraform subagent that builds modules, wires up remote state and hunts drift. Useful once your infrastructure outgrows a single main.tf. 1,349installs backup-before-edit A Claude hook that copies a file with a timestamp before every edit. Useful when the agent rewrites code and you want a way back. 1,328installs containerize-application A slash command that writes the Docker setup for your project: Dockerfile, .dockerignore, docker-compose and Kubernetes manifests. 1,200installs mermaid-diagrams A skill that teaches your agent Mermaid syntax: class, sequence, ERD, C4 and flowchart diagrams. Useful when you need to document architecture or a database schema. 1,180installs docs-maintenance This command audits documentation, links, structure, and style, then helps plan updates. Use it when Markdown docs need recurring checks. 1,146installs unity-game-developer A Claude subagent for Unity work: C# scripting, physics, UI, mobile optimization and cross-platform builds. 1,122installs document-structure-analyzer This subagent maps document regions, content hierarchy, and reading order. Use it before OCR when the relationships between headings, tables, and other elements matter. 1,099installs supabase-data-explorer This command explores Supabase data and schema, runs read-only SQL queries, and prepares exports or visualizations. Use it when database checks belong in the project workflow. 1,032installs