Blocks
Call workflow
The call workflow step: run another workflow synchronously with the upstream payload as its input, and continue with its result.
Run another workflow as a function call: the upstream payload becomes the target's input, the run waits, and the target's final output becomes this step's output. The other half of the sub-workflow trigger.
Config
One picker: the target workflow.
The target must have a sub-workflow trigger and be active — the picker steers you toward workflows that qualify.
Output
Whatever the called workflow's terminal step emitted. Document your sub-workflows' output contracts — the caller is coupled to them.
Patterns
- Shared tail — one "notify the team" workflow every other workflow calls; changing the channel is one edit.
- Decomposition — a monster pipeline split into testable, reusable parts.
- Agents can do this too: an AI step with a workflow tool decides when to call.
Gotchas
- Failure cascades: if the called workflow fails, this step fails.
Set this step's on-error to
continue(or branch on the output) when the parent should survive. - The parent waits synchronously — a slow sub-workflow is a slow parent. Call depth is bounded, so cycles stop at the limit rather than recursing forever.