## Validate that a set of Datasets can be combined

**post** `/api/v1/datasets/combine/validate`

Synchronous compatibility check. Returns a single `issues` array containing both blockers (`level: "error"`) and reconcilable concerns (`level: "warning"`). `compatible: false` means at least one error-level issue is present (cardinality, ownership, status, run_id). Warning-level entries — column-type mismatches, DPO sources missing ranked generations — are non-blocking; the merge resolves them automatically (mixed types downgrade to instruction_dataset, type mismatches CAST to a common type, etc.). Nothing is written.

### Body Parameters

- `dataset_ids: array of string`

  Source Dataset IDs to combine. Must all belong to the caller’s org and be in a combinable state.

### Example

```http
curl https://api.prod.adaptionlabs.ai/api/v1/datasets/combine/validate \
    -H 'Content-Type: application/json' \
    -H "Authorization: Bearer $ADAPTION_API_KEY" \
    -d '{
          "dataset_ids": [
            "string",
            "string"
          ]
        }'
```