/debugging-executions

name: debugging-executions
description: >-
  Debug failed or wrong-output workflow executions using executions tools. Load
  when the user reports execution failures, unexpected node output, empty
  parameter values after a successful run, or a node showing a red or failed
  expression error.
recommended_tools:
  - executions
  - workflows

Debugging Executions

Use this skill when debugging workflow execution failures or successful runs with wrong or empty values.

When the user reports it still fails

Re-run the failing path with `executions(action="run")` (or `verify-built-workflow`) and inspect the real result before responding. Do not restate that the workflow is "fixed", "verified", or "working", and do not attribute the reported failure to a test-harness artifact, stale state, or "it works in production" without a re-run against the failing path. Treat live signals as real: an execution error, partial coverage (`nodesNotReached`), an empty node, or a missing node is a real defect to investigate, not something to explain away. If you genuinely cannot re-run the failing path, say so plainly and name what is unconfirmed instead of repeating a success claim.

Testing event-triggered workflows

Use `executions(action="run")` with `inputData` matching the trigger's output shape — do not rebuild the workflow with a Manual Trigger. For trigger `inputData` shapes, read `${N8N_WORKSPACE_DIR}/knowledge-base/reference/trigger-input-data-shapes.md` when a sandbox workspace is available.

Failed execution

`executions(action="debug")` already includes `failedNode.resolvedParameters` — start there. That bundle has `parameters` (raw, with expressions intact), `resolved` (substituted), `failedExpressions` (those that threw), and `emptyResolutions` (those that resolved to `null`/`undefined`/`""` silently). The offending expression is usually visible without a follow-up call. Entries in either list tagged with `reason: "unreconstructable-context"` are NOT real bugs — they reference variables we don't reconstruct in replay (`$vars`, `$secrets`, `$response`, `$request`, `$pageCount`, `$ai`). The value existed at execution time; we just don't have it here.

Successful execution with wrong or empty value

When `debug` doesn't apply because nothing errored, call `executions(action="get-resolved-node-parameters", executionId, nodeName)` on the node whose output looks off — **do this unprompted**, don't ask the user for permission first. It's a cheap read-only inspection and the only reliable way to confirm whether an empty value came from an expression silently resolving to nullish. Check `emptyResolutions` first; most "this parameter is empty" cases are expressions resolving to `null`/`undefined`/`""`, not thrown errors.