DynamoDB-compatible API

export MTS_LOCAL_CLUSTER_NAME=preview-ddb
export MTS_LOCAL_LEASE_BACKEND=file
export MTS_LOCAL_DDB_BASE_PORT=8000
bash scripts/local-cluster.sh start

AWS JSON protocol shape

curl -X POST "http://127.0.0.1:8000/" \
  -H "Content-Type: application/x-amz-json-1.0" \
  -H "X-Amz-Target: DynamoDB_20120810.Query" \
  -d '{
    "TableName": "Docs",
    "KeyConditionExpression": "tenant = :tenant and begins_with(id, :prefix)",
    "ExpressionAttributeValues": {
      ":tenant": {"S": "tenant-alpha"},
      ":prefix": {"S": "doc-"}
    },
    "Limit": 25
  }'

Item operations

{
  "TableName": "Docs",
  "Item": {
    "tenant": {"S": "tenant-alpha"},
    "id": {"S": "doc-1"},
    "title": {"S": "Refund policy"}
  },
  "ReturnConsumedCapacity": "TOTAL"
}

{
  "TableName": "Docs",
  "Key": {
    "tenant": {"S": "tenant-alpha"},
    "id": {"S": "doc-1"}
  },
  "ProjectionExpression": "tenant, id, title",
  "ConsistentRead": true
}

{
  "TableName": "Docs",
  "Key": {
    "tenant": {"S": "tenant-alpha"},
    "id": {"S": "doc-1"}
  },
  "UpdateExpression": "SET title = :title",
  "ExpressionAttributeValues": {
    ":title": {"S": "Updated refund policy"}
  },
  "ReturnValues": "ALL_NEW"
}

Query

Query requires equality on the table or index hash key. The optional sort-key predicate may be equality, comparison, BETWEEN, or begins_with for string/binary sort keys.

{
  "TableName": "Docs",
  "IndexName": "tenant_category_idx",
  "KeyConditionExpression": "tenant = :tenant AND category = :category",
  "FilterExpression": "status = :status",
  "ProjectionExpression": "tenant, id, title",
  "ExpressionAttributeValues": {
    ":tenant": {"S": "tenant-alpha"},
    ":category": {"S": "returns"},
    ":status": {"S": "open"}
  },
  "ScanIndexForward": false,
  "Limit": 50,
  "ReturnConsumedCapacity": "INDEXES"
}

Supported key-condition shapes:

Scan

Scan is present for compatibility but should not be treated as a safe serving-query substitute. Prefer Query or an MTS access path.

{
  "TableName": "Docs",
  "FilterExpression": "category = :category",
  "ExpressionAttributeValues": {
    ":category": {"S": "returns"}
  },
  "Limit": 25
}

Batch and transaction operations

{
  "RequestItems": {
    "Docs": {
      "Keys": [
        {
          "tenant": {"S": "tenant-alpha"},
          "id": {"S": "doc-1"}
        }
      ],
      "ProjectionExpression": "tenant, id, title"
    }
  },
  "ReturnConsumedCapacity": "TOTAL"
}

{
  "TransactItems": [
    {
      "Put": {
        "TableName": "Docs",
        "Item": {
          "tenant": {"S": "tenant-alpha"},
          "id": {"S": "doc-2"},
          "title": {"S": "Transactional write"}
        }
      }
    },
    {
      "Update": {
        "TableName": "Docs",
        "Key": {
          "tenant": {"S": "tenant-alpha"},
          "id": {"S": "doc-1"}
        },
        "UpdateExpression": "SET status = :status",
        "ExpressionAttributeValues": {
          ":status": {"S": "review"}
        }
      }
    }
  ]
}