curl --request POST \
  --url https://api.example.com/checkpoints/get-tuple \
  --header 'Content-Type: application/json' \
  --data '
{
  "thread_id": "<string>",
  "checkpoint_ns": "",
  "checkpoint_id": "<string>"
}
'

{
  "thread_id": "<string>",
  "checkpoint_ns": "<string>",
  "checkpoint_id": "<string>",
  "checkpoint": {},
  "metadata": {},
  "parent_checkpoint_id": "<string>",
  "blobs": [
    {
      "channel": "<string>",
      "version": "<string>",
      "type": "<string>",
      "blob": "<string>"
    }
  ],
  "pending_writes": [
    {
      "task_id": "<string>",
      "idx": 123,
      "channel": "<string>",
      "type": "<string>",
      "blob": "<string>"
    }
  ]
}