Software architecture diagrams with AI
OpenCharts is an AI architecture-diagram tool that turns a code description, ADR, or system context prompt into an editable software architecture diagram. Theo identifies services, data stores, queues, external systems, and arrows of communication, applies a clean block layout, and supports C4-style context, container, and component levels. Free real-time collaboration, exports to PNG/SVG/PDF/PPTX, and a public MCP server for AI coding agents.
How it works
- 1
Describe the system
Tell Theo about the system in plain English: services, data stores, queues, third-party APIs, deployment regions. Or upload an existing diagram or ADR.
- 2
Pick a level
C4-style: context (people + systems), container (services + data stores), component (modules within a service). Theo will produce the right level of detail.
- 3
Refine the layout
Drag services, group by team or domain, color-code by ownership, and attach data tables for SLAs, dependencies, and contact info.
- 4
Share with engineering and stakeholders
Public share link, embed on internal docs, or export to PPTX for a leadership review.
What you get
- C4-style context / container / component diagrams
- Service, data store, queue, lambda, gateway, and external system node types
- Group containers for tenancy, regions, and bounded contexts
- Color-coding by team, owner, or criticality
- Real-time multiplayer collaboration
- Public MCP server: drive diagrams from Claude Desktop, Cursor, Warp, or VS Code
Frequently asked questions
Does OpenCharts support C4 diagrams?
Yes. You can build C4-style diagrams (context, container, component, code) using the structured node types and templates. Theo can generate any level from a system description.
Can my AI coding agent edit the diagram?
Yes. The OpenCharts MCP server exposes 19 tools (project CRUD, AI extraction, Theo chat) so any MCP-compatible client (Warp, Claude Desktop, Cursor, VS Code, Windsurf) can read and write architecture diagrams with bearer-token auth.
Can I generate a diagram from a code repo?
Indirectly: paste a `tree` listing or a high-level description into Theo and ask for an architecture diagram. For deeper code-aware extraction, use the MCP server to feed structured context from your tooling.
Are AWS or GCP icons supported?
OpenCharts ships generic service/storage/queue icons that work for any cloud. Branded provider iconography is on the roadmap. Custom node images can be uploaded for any cloud-specific representation today.
Is this free?
Yes. Architecture diagrams, real-time collaboration, and export are included on every plan including the free tier.
Compare to other tools
Try it free with OpenCharts
No credit card required. Free real-time collaboration and full export on every plan.