Mermaid charts not rendering in CLI

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1

Where does the bug appear (feature/product)?

Cursor CLI

Describe the Bug

Mermaid charts are showing as plain text instead of rendering as flowcharts in plan mode. Example rendered text from a planning session:

 │                                                                                          │
 │ flowchart LR                                                                             │
 │   groupedAtom[GroupedAtom] --> rawGroups[RawServerGroups]                                │
 │   groupedAtom --> mergedHook[useProductGroups]                                           │
 │   mergedHook --> liveGroups[LiveMergedGroups]                                            │
 │   rawGroups --> visibleFilter[ServerVisibilityFilter]                                    │
 │   visibleFilter --> displayedGroups[DisplayedLiveGroups]                                 │
 │   liveGroups --> displayedGroups                                                         │
 │   displayedGroups --> uiState[CheckboxesAndHeaders]

Steps to Reproduce

Unfortunately I’m not able to reproduce trivially, asking the agent to make a dummy plan with a mermaid chart correctly renders the chart. However, when making plans in the context of actual code this seems to happen every time.

Expected Behavior

Charts should always render in plans.

Operating System

MacOS

Version Information

CLI Version 2026.03.20-44cb435

For AI issues: which model did you use?

Most recently happening with GPT-5.4 Extra High Fast, not sure if model specific though.

Does this stop you from using Cursor

No - Cursor works, but with this issue

5

Hey Nate!

I believe this might be a feature rather than a bug.

When the CLI window is too narrow to render the Mermaid chart properly, it reverts to text.

When the window is expanded again, the Mermaid chart displays correctly!

If you expand your terminal, do you see the mermaid chart properly render?