GitHub Actions "a step cannot have both the uses and run keys"

By Daniel Zoghalchali·Latchkey

A step is either an action (uses) or a shell command (run), never both. Declaring uses and run in the same step is ambiguous and rejected at parse time.

What this error means

The workflow fails to start with "a step cannot have both the uses and run keys", pointing at a step that declares both.

Error: a step cannot have both the `uses` and `run` keys

Common causes

Merged two steps into one

An action step and a command step were accidentally combined under a single list item.

Indentation collapsed two steps

Wrong YAML indentation made a run line attach to a uses step.

How to fix it

Split into separate steps

1. Put the action in its own step with uses.
2. Put the command in a separate step with run.
3. Fix indentation so each is a distinct list item.

steps:
  - uses: actions/checkout@v4
  - run: npm ci && npm test

How to prevent it

• Keep one action or one command per step, never both.
• Watch step indentation so lines do not merge.
• Lint workflows to catch uses+run on one step.

Frequently asked questions

Related guides

References

• GitHub Actions documentation
• Workflow syntax for GitHub Actions