Error reference / any

No diagram type detected

The source doesn't start with a Mermaid diagram keyword, so the renderer has nothing to match against any known grammar.

No diagram type detected matching given configuration for text: hello world
    this is not mermaid

Why this happens

Every Mermaid document must open with a diagram type keyword -- flowchart, sequenceDiagram, classDiagram, stateDiagram-v2, erDiagram, gantt, pie, journey, and so on. Without one, Mermaid has no grammar to parse the rest of the text against.

This also happens when the keyword is misspelled, or when leftover prose or markdown formatting (like a stray ``` fence) ends up inside the Mermaid code block.

How to fix it

Add the correct diagram keyword as the very first non-comment line. Check spelling and capitalization -- sequenceDiagram is camelCase, stateDiagram-v2 needs the version suffix.

If you copied the snippet from a markdown file, make sure the ```mermaid fence itself isn't included inside the source you're rendering.

Broken

Fails to parse

Rendering preview...
Users click sign up
Then they verify their email
Then they land on the dashboard
Open broken version in studio

Fixed

Renders correctly

Rendering preview...
flowchart TD
    signup[Users click sign up] --> verify[Verify email] --> dashboard[Land on dashboard]
Open fixed version in studio

More errors

flowchartgraph

Parse error: got 'CALLBACKNAME'

A node ID exactly matches a Mermaid keyword (call, click, or href) and is referenced without a shape, so the parser reads it as a click-callback token instead of a node name.

flowchartgraph

Parse error: got 'SQS'

A node's square-bracket label was never closed, so the parser runs into the next node's opening bracket before it finds the one it was expecting.

flowchartgraph

Parse error: got 'PS'

A square-bracket label contains a raw ( or ), which Mermaid reads as the start of a different node shape rather than as label text.