ListLanceTasks - OSS Tables API - Object Storage Service

Permission notes

API	Action	Description
ListLanceTasks	oss:GetTableMaintenanceJobStatus	Lists maintenance tasks.

Request syntax

GET /lance/oss/v1/table/{id}/tasks?task_type=lance_compact&max_results=100 HTTP/1.1
Host: {tableBucketHost}
Date: GMT Date
Authorization: SignatureValue

# Next page:
# GET /lance/oss/v1/table/{id}/tasks?task_type=lance_compact&max_results=100&marker={next_marker} HTTP/1.1

Request parameters

For the common conventions of this interface (access address, table identifier, request and response headers, permissions, async submission and quota, task status, error codes), see Lance table maintenance.

Parameter	Location	Data type	Required	Description
id	path	string	Yes	Current table identifier.
task_type	query	string	Yes	Must be one of the five complete types listed below.
max_results	query	int32	No	Default value 100. Maximum number of tasks returned per page, range [1, 1000].
marker	query	string	No	Not sent by default. Opaque pagination token; use the next_marker from the previous response verbatim, and encode it correctly as a Query parameter.
delimiter	query	string	No	Default value $. Table identifier delimiter.

Allowed task_type values and constraints

lance_compact
lance_scalar_index
lance_vector_index
lance_optimize_indices
lance_cleanup

Path action names such as compact and create_scalar_index are not valid task_type values. A single request lists only one type. The mode and status Query parameters are not supported; as soon as either parameter appears, 400 / InvalidInput / 13 is returned, including for empty values. Status filtering should be performed by the client on the returned results.

Response

HTTP/1.1 200 OK
Content-Type: application/json
x-oss-table-id: {table_id}

{
  "tasks": [
    {
      "task_id": "123xxxxxxxxxxxxxxx",
      "task_type": "lance_compact",
      "params": {
        "target_rows_per_fragment": 1048576,
        "materialize_deletions": true,
        "materialize_deletions_threshold": 0.1,
        "max_rows_per_group": 1024,
        "max_bytes_per_file": 0,
        "compaction_mode": "reencode"
      },
      "status": "submitted",
      "created_at": "2026-09-18T04:00:00.000000+00:00",
      "started_at": "",
      "completed_at": "",
      "result": {},
      "error": null
    }
  ],
  "next_marker": "",
  "is_truncated": false
}

Response parameter	Type	Description
tasks	object[]	Task list for the current page. Elements use the task object directly, without an additional task_info wrapper. See the table below for element fields.
next_marker	string	Pagination token returned when there are more valid tasks; an empty string on the last page.
is_truncated	boolean	true indicates there is another page of valid tasks.

The fields contained in tasks are as follows:

Field	Type	Description
task_id	string	Task ID.
task_type	string	One of the five lance_ prefixed types.
params	object	The actually saved task parameters, including server-filled default values.
status	string	Current task status.
created_at	string	Task creation time.
started_at	string	Task start time; an empty string when not started.
completed_at	string	Time when the task entered a terminal state; an empty string for non-terminal states.
result	object	Task execution result, initially {}; may contain nested objects and arrays. The result structure varies by task type.
error	object or null	Contains an error object when the known status is failed; null for other known statuses.

When there are no tasks, {"tasks":[],"next_marker":"","is_truncated":false} is returned. The first page should omit marker. An explicitly empty marker, an illegal token, or using a token across tables or across task_type values all return 400 / InvalidContinuationToken /13. Do not use an internal index path as marker.

The server skips orphan indexes missing task records, malformed indexes, and duplicate indexes with old timestamps, and only sets is_truncated=true after confirming that a next valid task exists. A corrupted task body may cause an internal error. Pagination is not a fixed point-in-time snapshot; under concurrent submissions or deletions, the client must not assume the task set is completely unchanged.

Error codes

This interface uses the Lance unified JSON error format. For common error codes and the error response structure, see Lance table maintenance in the common conventions.