What causes "Together API key is required" in mem0ai/mem0?

Export TOGETHER_API_KEY with a key from the Together settings page.

Together API key is required

Error message

Together API key is required

What it means

Thrown synchronously by the TogetherLLM constructor when no Together AI API key is resolved. The provider checks config.apiKey, then the TOGETHER_API_KEY environment variable, and throws when both are missing — the fail-fast guard before building the OpenAI-compatible client for api.together.ai.

Source

Thrown at mem0-ts/src/oss/src/llms/together.ts:9

import { OpenAILLM } from "./openai";
import { LLMConfig, Message } from "../types";
import { LLMResponse } from "./base";

export class TogetherLLM extends OpenAILLM {
  constructor(config: LLMConfig) {
    const apiKey = config.apiKey || process.env.TOGETHER_API_KEY;
    if (!apiKey) {
      throw new Error("Together API key is required");
    }
    super({
      ...config,
      apiKey,
      baseURL:
        config.baseURL ||
        process.env.TOGETHER_API_BASE ||
        "https://api.together.ai/v1",
      model: config.model || "MiniMaxAI/MiniMax-M3",
    });
  }

  async generateResponse(
    messages: Message[],
    responseFormat?: { type: string },
    tools?: any[],
  ): Promise<string | LLMResponse> {
    try {

View on GitHub (pinned to 001c235229)

Solutions

Export TOGETHER_API_KEY with a key from the Together settings page.
Or pass it explicitly: llm: { provider: 'together', config: { apiKey: process.env.TOGETHER_API_KEY } }.
Load dotenv before constructing Memory.
Add TOGETHER_API_KEY to deployment/CI secrets.

Example fix

// before
const mem = new Memory({ llm: { provider: 'together', config: {} } });
// throws: Together API key is required

// after
import 'dotenv/config';
const mem = new Memory({
  llm: { provider: 'together', config: { apiKey: process.env.TOGETHER_API_KEY! } },
});

Defensive patterns

Strategy: validation

Validate before calling

function assertTogetherKey(cfg: LLMConfig) {
  if (!cfg.apiKey && !process.env.TOGETHER_API_KEY) {
    throw new Error('TOGETHER_API_KEY not set — create one at api.together.ai/settings/api-keys');
  }
}

Type guard

const hasTogetherKey = (cfg: LLMConfig): boolean => Boolean(cfg.apiKey || process.env.TOGETHER_API_KEY);

Try / catch

try { new TogetherLLM(config); } catch (e) {
  if ((e as Error).message === 'Together API key is required') throw new StartupConfigError('TOGETHER_API_KEY missing');
  throw e;
}

Prevention

Export TOGETHER_API_KEY (exact name) or pass apiKey in config.
Load dotenv before constructing Memory.
Validate provider-specific env vars in a boot schema check.

When it happens

Trigger: Instantiating TogetherLLM (provider 'together') with apiKey absent/empty and TOGETHER_API_KEY unset at construction time.

Common situations: Key not created at api.together.ai/settings/api-keys; env var set only in local shell but missing in CI/production; dotenv loaded after Memory construction; key name typo (TOGETHERAI_API_KEY).

Related errors

AI-assisted analysis of mem0ai/mem0@001c235229 (2026-08-15). Data as JSON: /api/errors/b365bfad5b08fc28. Report an issue: GitHub.