Engines

A profile is a static description of a deployment. You pass one to a layer as profile, and the client applies its rules before it sends anything. Profiles never ask the server what it is.

Example (Declaring a Valkey Engine)

import { RedisProfiles } from "@effect-kit/redis";
import { RedisNode } from "@effect-kit/redis/node";

export const RedisLive = RedisNode.layer({
  url: "redis://localhost:6379",
  profile: RedisProfiles.valkey({ modules: ["json"] }),
});

Profiles are optional. Without one, the client sends every command and the server decides.

Engine profilesCopy Anchor Link

An engine profile leaves TLS and authentication optional, allows any database, and restricts no command. Its checks are about how you connect:

• A profile whose routing does not match the layer fails with ProfileError and reason: "routing". A standalone profile does not work with layerCluster.
• modules lists the modules your server really has. A command from a module that is not in the list fails with ProfileError and reason: "module" before it is sent. Without modules, the server decides.

All ProfileError failures have delivery: "unsent".

Engine-specific rulesCopy Anchor Link

The only command rule in an engine profile is for Garnet. The Garnet profile rejects ZSCAN with NOSCORES, because Garnet v2.2.4 ignores the flag, and typed replies could then not tell scores from members. The command fails with ProfileError and reason: "restricted-command".

Everything else an engine does not implement comes back from the server as a ServerError.

Example (Rejecting a Module Command Before Sending)

import { Effect } from "effect";
import { Redis, RedisProfiles } from "@effect-kit/redis";
import { RedisNode } from "@effect-kit/redis/node";

const RedisLive = RedisNode.layer({
  url: "redis://localhost:6379",
  profile: RedisProfiles.redis({ modules: ["json"] }),
});

export const program = Effect.gen(function* () {
  const redis = yield* Redis;
  return yield* redis.ftList();
}).pipe(
  Effect.catchTag("ProfileError", (error) =>
    error.reason === "module" ? Effect.succeed([]) : Effect.fail(error),
  ),
  Effect.provide(RedisLive),
);

How engines are testedCopy Anchor Link

Each engine runs the package's conformance cases once, on the version listed in Compatibility. The cases cover strings, keys, collections, ordered sets, sessions, events, modules and administration, over RESP2 and RESP3, on Node.js and Bun. Garnet also runs a case with its Lua support enabled.

Dragonfly, KeyDB, Redict, Garnet and Kvrocks run with no modules. Do not expect JSON or Search on them.