What causes "No Mistral API key was set." in Mintplex-Labs/anything-llm?

Add MISTRAL_API_KEY to server/.env with a valid key from console.mistral.ai.

Mintplex-Labs/anything-llm · critical · Error

No Mistral API key was set.

Error message

No Mistral API key was set.

What it means

Constructor guard mirroring Minimax: MistralLLM throws at construction if process.env.MISTRAL_API_KEY is absent. The key feeds the OpenAI-compatible client at https://api.mistral.ai/v1. (The later `?? null` on the apiKey is moot since the constructor already guaranteed presence.)

Source

Thrown at server/utils/AiProviders/mistral/index.js:13

const { NativeEmbedder } = require("../../EmbeddingEngines/native");
const {
  LLMPerformanceMonitor,
} = require("../../helpers/chat/LLMPerformanceMonitor");
const {
  handleDefaultStreamResponseV2,
  formatChatHistory,
} = require("../../helpers/chat/responses");

class MistralLLM {
  constructor(embedder = null, modelPreference = null) {
    if (!process.env.MISTRAL_API_KEY)
      throw new Error("No Mistral API key was set.");

    this.className = "MistralLLM";
    const { OpenAI: OpenAIApi } = require("openai");
    this.openai = new OpenAIApi({
      baseURL: "https://api.mistral.ai/v1",
      apiKey: process.env.MISTRAL_API_KEY ?? null,
    });
    this.model =
      modelPreference || process.env.MISTRAL_MODEL_PREF || "mistral-tiny";
    this.limits = {
      history: this.promptWindowLimit() * 0.15,
      system: this.promptWindowLimit() * 0.15,
      user: this.promptWindowLimit() * 0.7,
    };

    this.embedder = embedder ?? new NativeEmbedder();
    this.defaultTemp = 0.0;
    this.log("Initialized with model:", this.model);

View on GitHub (pinned to 526360e320)

Solutions

Add MISTRAL_API_KEY to server/.env with a valid key from console.mistral.ai.
Restart the server to reload env.
Confirm process.env.MISTRAL_API_KEY is populated in the running process.
For containerized deploys, inject the env var into the container spec.

Example fix

// server/.env
MISTRAL_API_KEY=your_key_here
MISTRAL_MODEL_PREF=mistral-tiny

Defensive patterns

Strategy: validation

Validate before calling

if (!process.env.MISTRAL_API_KEY) {
  throw new Error('MISTRAL_API_KEY missing — set it before enabling Mistral.');
}

Try / catch

try {
  const llm = new MistralLLM(embedder, modelPref);
} catch (e) {
  if (/No Mistral API key/i.test(e.message)) {
    // config error — guide user to set MISTRAL_API_KEY
  }
}

Prevention

Validate Mistral credentials in the provider factory before construction.
Run a startup env check for every enabled provider's key.
Keep the admin credential form and provider selector coupled.

When it happens

Trigger: Instantiating `new MistralLLM(...)` when MISTRAL_API_KEY is unset/empty. AnythingLLM hits this when the workspace provider is set to Mistral but credentials are missing.

Common situations: Mistral provider selected without configuring the key; .env not reloaded after editing; typo (MISTRAL_APIKEY, MISTRAL_KEY); secret dropped from the deployment env.

Related errors

AI-assisted analysis of Mintplex-Labs/anything-llm@526360e320 (2026-08-13). Data as JSON: /api/errors/4bf492818fd73cb0. Report an issue: GitHub.