SADD

Adds one or more members to a set. Creates the key if it doesn’t exist.

Browse all commands · Upstream source documentation

Reference field	Value
Canonical name	SADD
Catalog group	Set commands
Upstream since	1.0.0 — upstream Redis/module version, not an ffkv release
Pinned catalog	Redis 8.10.0

Syntax

SADD key member [member ...]

ffkv behavior and limits

Members are binary-safe and unique. Sampling and pop order are not stable; preserve the distinction between destructive pops and reads. Hybrid mode does not offload set bodies.

Source: README.md:275–295, 810–825; tests/bdd/features/sets.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(1) for each element added, so O(N) to add N elements when the command is called with multiple arguments.

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

Command flags: WRITE, DENYOOM, FAST.

ACL categories: SET.

Argument structure

Argument	Type	Constraints / metadata
key	key	key_spec_index: 0
member	string	multiple

Key specifications

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

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

Additional pinned upstream metadata

{
  "group": "set",
  "since": "1.0.0",
  "history": [
    [
      "2.4.0",
      "Accepts multiple `member` arguments."
    ]
  ]
}

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

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.

• Read only sorting resolves external keys and leaves an expiring set unchanged — tests/bdd/features/generic.feature:1304; invocation observed.
• Type distinguishes built in values and missing keys without inspecting their contents — tests/bdd/features/generic.feature:1352; invocation observed.
• Membership changes count distinct members and remove empty keys — tests/bdd/features/sets.feature:5; command tag and invocation observed.
• Membership queries preserve duplicate query positions — tests/bdd/features/sets.feature:57; invocation observed.
• Set replies contain each distinct member once — tests/bdd/features/sets.feature:97; invocation observed.
• SDIFF respects overlapping and missing sources — tests/bdd/features/sets.feature:122; invocation observed.
• SINTER respects overlapping and missing sources — tests/bdd/features/sets.feature:147; invocation observed.
• SUNION respects overlapping and missing sources — tests/bdd/features/sets.feature:172; invocation observed.
• SDIFFSTORE can overwrite an input after computing the result — tests/bdd/features/sets.feature:197; invocation observed.
• SINTERSTORE can overwrite an input after computing the result — tests/bdd/features/sets.feature:237; invocation observed.
• SUNIONSTORE can overwrite an input after computing the result — tests/bdd/features/sets.feature:277; invocation observed.
• SDIFFCARD counts members with LIMIT and rejects invalid bounds — tests/bdd/features/sets.feature:317; invocation observed.
• SINTERCARD counts members with LIMIT and rejects invalid bounds — tests/bdd/features/sets.feature:375; invocation observed.
• SUNIONCARD counts members with LIMIT and rejects invalid bounds — tests/bdd/features/sets.feature:433; invocation observed.
• Moves preserve the source on wrongtype and handle same-key aliases — tests/bdd/features/sets.feature:507; invocation observed.
• Popping a singleton deletes the source and rejects negative counts — tests/bdd/features/sets.feature:568; invocation observed.
• Negative random counts sample with replacement without consuming members — tests/bdd/features/sets.feature:610; invocation observed.
• Scan filters a singleton and terminates at cursor zero — tests/bdd/features/sets.feature:647; invocation observed.
• SADD validates every source without replacing the destination — tests/bdd/features/sets.feature:676; command tag and invocation observed.
• Counted aliases and option words used as real keys remain unambiguous — tests/bdd/features/sets.feature:1198; invocation observed.
• Union applies per-input weights before aggregation including regular sets — tests/bdd/features/sorted_sets.feature:641; invocation observed.
• Intersection cardinality supports regular sets duplicate keys and LIMIT — tests/bdd/features/sorted_sets.feature:681; invocation observed.
• Only union and intersection accept regular set inputs — tests/bdd/features/sorted_sets.feature:1276; 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.

Membership changes count distinct members and remove empty keys — tests/bdd/features/sets.feature:7 (I execute:)

[
  "SADD",
  "s",
  "a",
  "a",
  "b"
]

Next source assertion: the reply equals:

2

SUNION respects overlapping and missing sources — tests/bdd/features/sets.feature:174 (the following commands succeed:)

[
  "SADD",
  "a",
  "only"
]

Popping a singleton deletes the source and rejects negative counts — tests/bdd/features/sets.feature:570 (the following commands succeed:)

[
  "SADD",
  "s",
  "only"
]