Objective

Allow the timeout-minutes frontmatter field to accept GitHub Actions expression strings (e.g. ${{ inputs.timeout }}) in addition to literal integer values, enabling reusable workflow_call workflows to customize timeout at call time.

Context

Tracked in issue #23724. The existing infrastructure in pkg/workflow/templatables.go already has preprocessIntFieldAsString and buildTemplatableIntEnvVar helpers for exactly this pattern. timeout-minutes is the lowest-risk field to start with.

Current Behavior

timeout-minutes: 30   # Only literal integers work
timeout-minutes: ${{ inputs.timeout }}  # ❌ Fails schema validation

Expected Behavior

timeout-minutes: 30                     # ✅ Literal integer
timeout-minutes: ${{ inputs.timeout }}  # ✅ Expression string

Approach

1. Update JSON schema in pkg/parser/schemas/main_workflow_schema.json:

   • Change timeout-minutes from type: integer to oneOf: [integer, expression-string] or use a pattern constraint to accept ${{ ... }} strings alongside integers.

2. Update FrontmatterConfig in pkg/workflow/frontmatter_types.go:

   • Change TimeoutMinutes int to TimeoutMinutes *string (templatable pattern).

3. Update frontmatter parsing in pkg/workflow/frontmatter_types.go (or wherever TimeoutMinutes is populated):

   • Call preprocessIntFieldAsString(data, "timeout-minutes", log) before unmarshaling.

4. Update compilation in pkg/workflow/compiler_yaml.go (or wherever timeout-minutes is emitted to the compiled YAML):

   • Use templatableIntValue() for compile-time integer paths.
   • Use buildTemplatableIntEnvVar where the expression needs to be passed to runtime.
   • Ensure timeout-minutes in the compiled YAML receives the expression correctly (GitHub Actions evaluates ${{ inputs.timeout }} in the YAML at runtime).

5. Rebuild binary: make build (schema embedded via //go:embed).

6. Add/update tests: Cover literal integer, expression string, and invalid string cases.

Files to Modify

• pkg/parser/schemas/main_workflow_schema.json — relax type constraint
• pkg/workflow/frontmatter_types.go — change field type to *string
• pkg/workflow/compiler_yaml.go (or compiler output code) — handle expression in emitted YAML
• Test files in pkg/workflow/ or pkg/parser/

Acceptance Criteria

• timeout-minutes: 30 still works (backward compatible)
• timeout-minutes: ${{ inputs.timeout }} compiles and the expression appears correctly in the compiled .lock.yml
• Invalid strings (non-expressions) produce a clear error message
• Schema validation accepts the new type union
• Tests pass: make agent-finish
  Related to Ask: Runtime Parameterization of Compile-Time Frontmatter Fields #23724

Generated by Plan Command for issue #23724 · ◷

• expires on Apr 3, 2026, 5:44 AM UTC