EVALSHA_RO

Executes a read-only server-side Lua script by SHA1 digest.

Browse all commands · Upstream source documentation

Reference field	Value
Canonical name	EVALSHA_RO
Catalog group	Scripting commands
Upstream since	7.0.0 — upstream Redis/module version, not an ffkv release
Pinned catalog	Redis 8.10.0

Syntax

EVALSHA_RO sha1 numkeys [key [key ...]] [arg [arg ...]]

The catalog’s command-name typography is corrected here to the exact canonical spelling; the source catalog is unchanged.

ffkv behavior and limits

Sandboxed Lua 5.1 is bounded to 1 million instructions, 32 MiB Lua memory, 64 nesting levels, 8 MiB scripts/bridge values/replies, 10,000 bridge calls and 16 MiB cumulative bridge arguments. Writes before runtime errors commit. The volatile SHA cache holds 256 scripts/16 MiB with FIFO eviction; durable function libraries cap at 256 and one 16 MiB encoded WAL frame.

Source: README.md:426–449; tests/bdd/features/scripting.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: Depends on the script that is executed.

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

Command flags: NOSCRIPT, SKIP_MONITOR, NO_MANDATORY_KEYS, STALE, SCRIPT_RUNNER, READONLY.

ACL categories: SCRIPTING.

Argument structure

Argument	Type	Constraints / metadata
sha1	string	Required
numkeys	integer	Required
key	key	optional; multiple; key_spec_index: 0
arg	string	optional; multiple

Key specifications

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

[
  {
    "flags": [
      "RO",
      "ACCESS"
    ],
    "begin_search": {
      "index": {
        "pos": 2
      }
    },
    "find_keys": {
      "keynum": {
        "keynumidx": 0,
        "firstkey": 1,
        "step": 1
      }
    }
  }
]

Additional pinned upstream metadata

{
  "group": "scripting",
  "since": "7.0.0"
}

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

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.

• Readonly scripts reject writes even through protected calls — tests/bdd/features/scripting.feature:76; command tag and invocation observed.
• Readonly script admission preserves legacy and explicit shebang metadata (Scenario Outline) — tests/bdd/features/scripting.feature:740; command tag and invocation observed.
• A valid write-capable shebang script rejects readonly entry points — tests/bdd/features/scripting.feature:770; 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.

Readonly script admission preserves legacy and explicit shebang metadata — tests/bdd/features/scripting.feature:755 (I execute:)

Expanded from an actual Examples row: source=return 42, reply=42.

[
  "EVALSHA_RO",
  {
    "saved": "readonly-metadata-digest"
  },
  0
]

Next source assertion: the reply equals:

42

Readonly scripts reject writes even through protected calls — tests/bdd/features/scripting.feature:95 (I execute:)

[
  "EVALSHA_RO",
  {
    "saved": "cached_read_digest"
  },
  "1",
  "readonly:key"
]

Next source assertion: the reply equals:

"original"

A valid write-capable shebang script rejects readonly entry points — tests/bdd/features/scripting.feature:798 (I execute:)

[
  "EVALSHA_RO",
  {
    "saved": "write-capable-digest"
  },
  0
]

Next source assertion: the reply is an error with code “ERR”