from retab import Retab

client = Retab()

plan = client.workflows.spec.plan(yaml_definition)

print(plan.action)
print(plan.rendered_plan)
for change in plan.resource_changes:
    print(change.actions, change.target, change.target_id)

{
  "workflow_id": "wf_abc123",
  "action": "update",
  "block_count": 2,
  "edge_count": 1,
  "diagnostics": {
    "issues": []
  },
  "format_version": "workflows-plan/v1",
  "summary": {
    "add": 0,
    "change": 1,
    "destroy": 0,
    "replace": 0,
    "noop": 0,
    "total": 1,
    "has_changes": true
  },
  "resource_changes": [
    {
      "address": "workflow.wf_abc123.block.block_extract",
      "target": "block",
      "target_id": "block_extract",
      "name": "Extract Fields",
      "type": "extract",
      "actions": ["update"],
      "summary": "Update block 'Extract Fields'",
      "change": {
        "before": {
          "label": "Extract Fields",
          "config": {
            "model": "gpt-4.1"
          }
        },
        "after": {
          "label": "Extract Fields",
          "config": {
            "model": "gpt-5.1"
          }
        },
        "before_sensitive": {},
        "after_sensitive": {},
        "field_changes": [
          {
            "path": ["config", "model"],
            "path_display": "config.model",
            "action": "update",
            "before": "gpt-4.1",
            "after": "gpt-5.1",
            "before_sensitive": false,
            "after_sensitive": false,
            "unified_diff": null
          }
        ]
      },
      "path": "extract-node"
    }
  ],
  "rendered_plan": "Workflow: wf_abc123\nPlan: 0 to add, 1 to change, 0 to destroy.\n\n~ workflow.wf_abc123.block.block_extract\n  block \"Extract Fields\" will be updated\n  ~ config.model\n    - 'gpt-4.1'\n    + 'gpt-5.1'"
}