eythaann/Seelen-UI · error · Error

no key provided to $t()

Error message

no key provided to $t()

What it means

The i18n helper `translate` (exposed as the `$t` store) requires a translation key string. It throws `no key provided to $t()` when the key argument is falsy (undefined, null, empty string). This is a programmer-error guard: calling `$t()` without specifying which string to look up can never succeed.

Source

Thrown at libs/ui/svelte/utils/i18n.ts:10

import { derived, get, writable } from "svelte/store";
import yaml from "js-yaml";

const _locale = writable("en");
const _messages = writable<Record<string, any>>({});

function translate(locale: string, key: string, vars: Record<string, string> = {}) {
  // Let's throw some errors if we're trying to use keys/locales that don't exist.
  // We could improve this by using Typescript and/or fallback values.
  if (!key) throw new Error("no key provided to $t()");
  if (!locale) throw new Error(`no translation for key "${key}"`);

  // Grab the translation from the translations object.
  // Support nested keys like "profile.log_out"
  const keys = key.split(".");
  let text = get(_messages)[locale];
  for (const k of keys) {
    text = text?.[k];
  }

  if (!text) {
    console.error(`no translation found for ${locale}.${key}`);
    // Try fallback to English
    let fallback = get(_messages)["en"];
    for (const k of keys) {
      fallback = fallback?.[k];
    }
    text = fallback || key;

View on GitHub (pinned to dee4aaa940)

Solutions

1. Pass a non-empty string key to `$t()`, e.g. `$t("profile.log_out")`.
2. If the key is dynamic, guard before calling: `key && $t(key)` or provide a default like `$t(key ?? "common.unknown")`.
3. Check the surrounding component for undefined props/config feeding the key expression and add a fallback.

Example fix

// before
<span>{$t(item.key)}</span>
// after
<span>{item.key ? $t(item.key) : ""}</span>

function safeT(t: (key: string, vars?: Record<string, string>) => string, key?: string | null) {
  return typeof key === "string" && key.length > 0 ? t(key) : "";
}

function hasKey(key: unknown): key is string {
  return typeof key === "string" && key.trim().length > 0;
}

try {
  label = $t(key);
} catch (e) {
  if (e instanceof Error && e.message === "no key provided to $t()") label = "";
  else throw e;
}

When it happens

Trigger: Calling the `t` store function as `$t()` or `$t("")` — e.g. a dynamic key expression that evaluates to empty/undefined because a variable was not set, a loop property name is missing, or a template literal interpolated an undefined value.

Common situations: Refactoring component labels to use i18n keys but forgetting to pass the key; keys read from config/props that are optional and undefined at first render; mistyping the call as `t(vars)` with the vars object as first arg while key is missing.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• no translation for key "${key}"
• LazyRune was not initialized
• no key provided to $t()
• no translation for key "${key}"
• Current monitor not found

AI-assisted analysis of eythaann/Seelen-UI@dee4aaa940 (2026-09-03). Data as JSON: /api/errors/59bacb309ad5985f. Report an issue: GitHub.