UNREACHABLE_NODE

What triggers it. Disconnected clusters left behind after remove_edge/remove_node mutations, or a cycle with no entry edge from the main flow.

How to fix it. Connect the node into the flow with add_edge from a reachable node, or delete it with remove_node if it is leftover.

See it fire

This minimal source triggers UNREACHABLE_NODE — checked at build time against the same engine the editor runs.

flowchart LR
  A[Start] --> B[Done]
  C[Orphan] --> D[Cycle]
  D --> C

Open in the editor and watch it clear

Run am verify diagram.mmd --json, inspect this code, and apply the smallest source or typed mutation that clears it. If it persists after two mechanical attempts, return the warning and ask for human review.

In the cloned repo, am is bun run bin/am.ts.

Back to all warning codes, or open the editor to watch this warning clear as you edit.