Platform
Diagrams that fit inside your docs.
40+ diagram types — architecture, sequence, ERD, BPMN, Gantt, charts, mind maps, freehand sketches. Drop one into any document and edit it inline, with or without AI help.
Looking for the full catalogue?
Adding a diagram
Open any document and click Insert Diagram in the toolbar (or press / and pick “Diagram”). You'll get three ways to bring a diagram to life — pick whichever suits the moment.
1. AI-generated (Business Process & more)
Describe what you want in plain English — “the customer approval workflow with swimlanes for sales, finance, and legal” — and Stable Baseline's agent picks the right diagram type, generates the source, and drops it into the page. Works for architecture, sequence, ERD, state machines, Gantt, and BPMN 2.0 with pools, lanes, and message flows.
2. Freeform sketch
When an idea needs a quick whiteboard, pick Freeform Diagram. You get an Excalidraw-style canvas to sketch by hand — rectangles, arrows, sticky notes, freehand ink. Great for brainstorming, storyboarding, or capturing a napkin sketch before it fades.
3. Diagrams as code
Prefer to write the source yourself? Pick Diagrams as Code to open the DSL editor. You get a split view — text on the left, live preview on the right — with syntax help for every supported DSL (Mermaid, PlantUML, D2, GraphViz, Vega-Lite, and more).
Editing with AI — even parts of a diagram
Click any diagram to open it in the editor. From there you can edit by hand, or ask the built-in agent to do it for you. The agent understands which diagram you're on and the shape of the source, so prompts like “add a retry loop after payment” or “split the ‘Billing’ lane into Stripe and finance” just work.
- Whole-diagram edits — “redraw this as a swimlane BPMN” or “convert to a sequence diagram”. The agent regenerates the source.
- Partial edits — select a node (or paste a specific label) and ask: “colour these three nodes red”, “rename the gateway to ‘Fraud check’”, “remove the cache path”.
- Annotations — “add an SLA note to the shipping task” drops a BPMN text annotation linked to the right node.
Always reversible
BPMN at full fidelity
Stable Baseline renders proper BPMN 2.0 — pools, lanes, message flows between pools, sequence flows inside them, gateways (exclusive, parallel), start/end events, and text annotations. It handles complex incident-response or cross-department workflows without forcing you to simplify.
Ask the agent “add a lane for tier-2 escalation” and the new lane slots in with a placeholder task and the flows that connect it. No manually shuffling XML. No re-laying out the canvas.
Sequence diagrams for flows
Sequence diagrams are the natural way to document an API flow or an auth handshake. Actors on top, lifelines down, messages between them.
Gantt for timelines
Plans inside Stable Baseline have a full Gantt view (see Plans & tasks), but you can also embed a Mermaid Gantt directly in a PRD or rollout document for a static snapshot.
ER diagrams for data models
Keep your schema documentation next to the API reference that reads from it — when one changes, you know exactly which other doc to check.
Alignment, captions, descriptions
- Alignment — left, centre, or right inside the document column.
- Caption — a single line under the diagram for context.
- Description — a 2–4 sentence prose description the AI uses for semantic search, so teammates can find the diagram by meaning, not just by title.
Versioning
Every save creates a new diagram version. Browse history from the editor, compare any two versions side-by-side (source and rendered SVG), and roll back if something broke. Diagram versions live in the same timeline as the document they belong to — one history, one source of truth.
Images vs diagrams
Diagrams are the canonical form — plain-text source, versioned, re-rendering cleanly at any size. If all you have is a screenshot (an architecture whiteboard, a customer-provided image, etc.), drop it in as an image instead — then ask the agent to transcribe it into a real diagram later.