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#1062 Nested workflow invocation does not apply the child workflow's input defaults

Opened by catjen · 7/10/2026· Shipped 7/10/2026

Description

When a workflow is invoked as a child (step task type: workflow), the child's declared input defaults are NOT applied. Any ${{ inputs.<name> }} reference to an unpassed-but-defaulted input fails evaluation with Invalid expression: No such key: <name>. Running the same child workflow directly at top level (swamp workflow run child ...) applies the default fine.

Steps to reproduce

  1. Child workflow:
name: child
inputs:
  properties:
    periodDir: { type: string }
    headed:
      type: boolean
      default: false
  required: ["periodDir"]
jobs:
  - name: main
    steps:
      - name: sync
        task:
          type: model_method
          modelIdOrName: some-model
          methodName: sync
          inputs:
            periodDir: ${{ inputs.periodDir }}
            headed: ${{ inputs.headed }}
        dependsOn: []
  1. swamp workflow run child --input periodDir=X -> works, headed resolves to false.
  2. Parent invoking the child without passing headed:
      - name: call-child
        task:
          type: workflow
          workflowIdOrName: child
          inputs:
            periodDir: ${{ inputs.periodDir }}
        dependsOn: []
  1. swamp workflow run parent --input periodDir=X

Expected

The child's input schema defaults are applied for nested invocations exactly as for top-level runs; the step succeeds with headed=false.

Actual

The parent step fails with:

Invalid expression: No such key: headed

>    1 | inputs.headed
                ^

Workaround

The parent passes every defaulted child input explicitly (e.g. headed: false).

Environment

swamp 20260710.093422.0-sha.05ac9e7f, Windows 11 x64.

02Bog Flow
✓OPEN✓TRIAGED✓IN PROGRESS✓SHIPPED+ 1 MOREASSIGNED+ 2 MOREREVIEW+ 4 MOREPR_MERGED+ 1 MORECONTRIBUTOR_NOTIFIED

Shipped

7/10/2026, 8:28:31 PM

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03Sludge Pulse
stack72 assigned stack727/10/2026, 6:19:55 PM
Editable. Press Enter to edit.

stack72 commented 7/10/2026, 8:28:40 PM

Thanks @catjen for reporting this! The fix has been merged and a release is on its way. We appreciate your contribution to swamp.

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