Dependency cycle detected: trace the reported node IDs through the graph

Symptoms and scope

A normal data-dependency loop prevents a valid execution order. This is different from a supported loop/control-flow node with explicitly defined semantics.

Error fragments for search; IDs, values and filenames may vary:

Dependency cycle detected
dependency_cycle

Source-supported context

Current validate_inputs detects an ordinary dependency cycle during traversal. The error puts a readable ID/class path in details and the distinct IDs in extra_info.cycle_nodes; cycle_path is an internal variable, not a response field. Core loop validation is a separate step and is skipped when a dependency cycle already exists. Dedicated loop or subgraph behavior must be checked against its own implementation. Source 1

Cases to distinguish

1. A downstream output was reconnected to an upstream required input.

2. An API graph generator reused the wrong ID or link and created a self-dependency.

3. A specialized control-flow structure was incorrectly flattened into ordinary dependencies.

Diagnostic sequence

The sequence below is an editorial procedure based on the cited context, not a diagnosis already confirmed for your environment.

Step 1. Save the original graph. In node_errors, read the dependency_cycle entry’s details path and extra_info.cycle_nodes IDs, then map those IDs and class types to the current graph. Display titles need not be unique.

Step 2. Inspect every edge in the cycle for incorrect rewiring, old IDs and copied references.

Step 3. Express iteration using the version's supported control flow or a finite expanded graph, starting from the author's minimal example.

Step 4. Re-export and validate, checking whether removing an edge introduced a missing required input.

Completion check

Invalid ordinary dependency cycles are gone while the intended iteration semantics remain, and the graph produces its result.

Limitations and cautions

This is based on the reviewed core; older versions may use other errors. Cutting an arbitrary wire can change the task, so preserve the original graph.

Original sources

• ComfyUI execution.py validation — source rechecked 2026-09-27.

Source review and separate English editorial pass: 2026-09-27. No local graph validation, workflow execution or GPU run occurred.

Related troubleshooting and guides

• Bad linked input: represent API connections with a source node and output slot
• Required input is missing: identify the exact node and field