XPENDING

Returns the information and entries from a stream consumer group’s pending entries list.

Browse all commands · Upstream source documentation

Reference field	Value
Canonical name	XPENDING
Catalog group	Stream commands
Upstream since	5.0.0 — upstream Redis/module version, not an ffkv release
Pinned catalog	Redis 8.10.0

Syntax

XPENDING key group [[IDLE min-idle-time] start end count [consumer]]

ffkv behavior and limits

Stream waits are bounded to 65,536 clients and 64 MiB of retained logical requests (also limited by the connection cap). Approximate MAXLEN trimming uses 100-entry granularity. EXEC/Lua reads never block. Physical index statistics describe ffkv, not Redis allocator internals.

Source: README.md:351–374; tests/bdd/features/streams.feature.

All requests share the 8 MiB framing/1,024-argument ingress limit; normal RESP replies have 64 MiB wire/logical budgets with bounded nesting/value counts. Management and Lua origins impose smaller budgets. These are not a process RSS cap. Catalog inclusion is not exhaustive option or wire-format parity. See limits and compatibility.

Upstream metadata

The following fields come from the pinned Redis metadata, not measured ffkv performance or an assertion that ffkv enforces every upstream flag. Running COMMAND INFO/COMMAND DOCS describe the current engine.

Upstream Redis complexity: O(N) with N being the number of elements returned, so asking for a small fixed number of entries per call is O(1). O(M), where M is the total number of entries scanned when used with the IDLE filter. When the command returns just the summary and the list of consumers is small, it runs in O(1) time; otherwise, an additional O(N) time for iterating every consumer.

Upstream arity: -3 (includes the command name; a negative number is a minimum).

Command flags: READONLY.

ACL categories: STREAM.

Command tips: NONDETERMINISTIC_OUTPUT.

Argument structure

Argument	Type	Constraints / metadata
key	key	key_spec_index: 0
group	string	Required
filters	block	optional
↳ min-idle-time	integer	optional; token: IDLE; since: 6.2.0
↳ start	string	Required
↳ end	string	Required
↳ count	integer	Required
↳ consumer	string	optional

Key specifications

Upstream key discovery descriptors (indexes are relative to the full command vector):

[
  {
    "flags": [
      "RO",
      "ACCESS"
    ],
    "begin_search": {
      "index": {
        "pos": 1
      }
    },
    "find_keys": {
      "range": {
        "lastkey": 0,
        "step": 1,
        "limit": 0
      }
    }
  }
]

Additional pinned upstream metadata

{
  "group": "stream",
  "since": "5.0.0",
  "history": [
    [
      "6.2.0",
      "Added the `IDLE` option and exclusive range intervals."
    ]
  ]
}

Metadata source · Local snapshot: src/command_metadata.json, key xpending.

BDD coverage and source examples

These are source observations, not a test run performed by this documentation build. A tag identifies scenario intent; an extracted vector identifies a command invocation, which may intentionally produce an error. Scenarios may require setup, multiple connections, persistence, cluster nodes or native-module fixtures.

• Groups create consumers deliver pending work and acknowledge ownership durably — tests/bdd/features/streams.feature:126; command tag and invocation observed.
• Claim and autoclaim transfer ownership and preserve message payload — tests/bdd/features/streams.feature:223; invocation observed.
• NACK releases owned work and makes it immediately claimable — tests/bdd/features/streams.feature:262; invocation observed.
• Group cursor reset redelivers history while consumer and group removal clear metadata — tests/bdd/features/streams.feature:301; invocation observed.
• ACKED deletion waits for all group acknowledgements and DELREF clears references — tests/bdd/features/streams.feature:373; invocation observed.
• ACKED trimming skips pending entries rather than stopping at them (Scenario Outline) — tests/bdd/features/streams.feature:620; command tag and invocation observed.
• Repeated reference policies reject the whole command without deleting entries or pending ownership (Scenario Outline) — tests/bdd/features/streams.feature:674; command tag and invocation observed.
• FORCE counts both creation and claim unless JUSTID or RETRYCOUNT changes the count (Scenario Outline) — tests/bdd/features/streams.feature:752; command tag and invocation observed.

Extracted command vectors

The following JSON arrays are the test harness’s argument vectors, not shell commands. Numeric arguments are converted by the harness; objects of the form {"base64":"…"} represent decoded binary bytes, not a literal JSON command argument. Preserve scenario setup and connection ordering. See the CLI guide for shell quoting and binary stdin. No reply is invented or inferred.

ACKED deletion waits for all group acknowledgements and DELREF clears references — tests/bdd/features/streams.feature:435 (I execute:)

[
  "XPENDING",
  "events",
  "a"
]

Next source assertion: the reply equals:

[0,null,null,null]

ACKED trimming skips pending entries rather than stopping at them — tests/bdd/features/streams.feature:642 (I execute:)

Expanded from an actual Examples row: strategy=MAXLEN, threshold=0.

[
  "XPENDING",
  "events",
  "g"
]

Next source assertion: the reply equals:

[1,"1-0","1-0",[["c","1"]]]

Groups create consumers deliver pending work and acknowledge ownership durably — tests/bdd/features/streams.feature:157 (I execute:)

[
  "XPENDING",
  "events",
  "workers"
]

Next source assertion: the reply equals:

[1,"1000-0","1000-0",[["alice","1"]]]