Sequence
Sequence diagram generator — from text to UML sequence
Explain who talks to whom and in what order, and ChartCraft draws the UML sequence diagram — lifelines, messages, and returns — perfect for APIs, auth flows, and protocols.
Prose in. Diagram out.
You type
The user logs in via the web app, which requests a token from the auth service. The auth service validates credentials against the database and returns a JWT to the app.
ChartCraft draws
How it works
Describe it
Write what you want in plain English — no syntax to learn.
ChartCraft compiles
It parses your description, builds the structure, and runs an automatic layout.
Refine & export
Tweak with follow-up messages, then export clean SVG or PNG.
Why ChartCraft
Lifelines & messages
Actors and systems become lifelines; calls and responses become time-ordered messages.
Great for APIs
Model request/response flows, auth handshakes, and protocols the way engineers actually read them.
Time-ordered layout
Messages are placed top-to-bottom in order, so the sequence is unambiguous.
The notation, in 30 seconds
Participants across the top, time flowing down, arrows for messages — the whole notation in five marks.
| Element | What it means |
|---|---|
| Participant / actor | A column in the conversation: user, service, database. Order them left-to-right by first involvement. |
| Lifeline (dashed vertical) | The participant's existence through time — messages attach to it. |
| Synchronous message (solid arrow) | A call that waits for an answer: POST /login, verifyPIN(). |
| Return (dashed arrow) | The reply flowing back: 200 OK, approval. Draw the ones that carry meaning. |
| Self-message | A participant doing internal work — validate, compute, retry. |
| Alt / opt fragments | Boxed regions for branches: the failure path, the optional step. |
Real examples, generated the same way
From the public examples gallery — every one produced from a plain-English description. Open one to see its prompt.
Questions
How do I make a sequence diagram from text?
Describe the interaction in order — who sends what to whom. ChartCraft produces a UML sequence diagram with lifelines and messages.
Is it UML-compliant?
Yes — actors, lifelines, synchronous messages, and returns follow UML sequence conventions.
Can I export it?
Yes, export to SVG or PNG with no watermark on any plan.
When should I use a sequence diagram instead of a flowchart?
When the interesting question is who talks to whom — API flows, auth handshakes, service interactions. If the question is what steps happen, a flowchart tells it better.
How do I show error handling?
With an alt fragment: the top region holds the success branch, the bottom the failure (payment declined, token expired). If the failure path grows large, give it its own diagram.