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Lemonfox AI Provider Guide

Lemonfox AI is a Tier-2 catalog provider: its integration is one JSON file (src/lib/providers/catalog/lemonfox-ai.json) rather than hand-written code.

Verification status: this entry is docs-verified only, not yet live-verified. The vendor's GET https://api.lemonfox.ai/v1/models needs a key (it answers HTTP 401 without one), so the two model ids come from the vendor's public chat API page, https://www.lemonfox.ai/apis/chat (retrieved 2026-09-29), and the roster has not been checked. No account was created and no API key was used to build it. evidence.liveMatrix is null until someone runs the live capability matrix with a real key (see Verification status below).

Key Facts​

  • Provider id: lemonfox-ai (alias lemonfox)
  • Protocol: OpenAI-compatible (/chat/completions) — the chat API page says "Our OpenAI-compatible API takes a list of messages as input and provides an AI-generated (assistant) message as output."
  • Base URL: https://api.lemonfox.ai/v1
  • Default model: deepseek-v4-flash
  • Models in catalog: 2, taken from the model table of https://www.lemonfox.ai/apis/chat
  • Streaming: supported — the page's stream parameter reads "incremental message updates are transmitted as server-sent events with data-only messages."
  • Tool calling: not declared (false) — the page's API Parameters section lists messages, model, max_tokens, stop, stream, frequency_penalty, presence_penalty, temperature and top_p
  • Tools while streaming: not declared (false)
  • Structured output: not declared (false), same parameter list as above
  • Structured output + tools together: not declared (false) — no combined probe was possible without credentials
  • Embeddings: not declared
  • Thinking: not declared
  • Billing: free-with-card is the growth queue's classification, one of the three values the catalog schema allows; see Billing below for the vendor's own wording
  • Key format: none declared

Quick Start​

1. Get an API key​

  1. Visit: https://lemonfox.ai/signup (the "Get started" and "Start Your Free Trial" links on https://www.lemonfox.ai/apis/chat both point to /signup); sign-up was not attempted while building this entry
  2. Create an API key at https://lemonfox.ai/apis/keys — https://www.lemonfox.ai/apis/chat links "create an API key" to that page, and the API's 401 reply says "You can obtain an API key from https://lemonfox.ai/apis/keys."
  3. Billing as the vendor states it: see Billing below
  4. Set LEMONFOX_AI_API_KEY in your .env file

2. Configure​

export LEMONFOX_AI_API_KEY=your-api-key
export LEMONFOX_AI_MODEL=deepseek-v4-flash   # optional — overrides the default model
export LEMONFOX_AI_BASE_URL=https://api.lemonfox.ai/v1   # optional — proxy or self-hosted gateway

3. Use it​

import { NeuroLink } from "@juspay/neurolink";

const neurolink = new NeuroLink();

const result = await neurolink.generate({
  input: { text: "Explain context windows in one paragraph." },
  provider: "lemonfox-ai",
  model: "deepseek-v4-flash",
});

console.log(result.content);
# CLI
npx @juspay/neurolink generate "Hello" --provider lemonfox-ai

Per-request credentials:

await neurolink.generate({
  input: { text: "Hello" },
  provider: "lemonfox-ai",
  credentials: { lemonfoxAi: { apiKey: process.env.LEMONFOX_AI_API_KEY } },
});

Billing​

What the vendor's public pages show (retrieved 2026-09-29):

The entry records free-with-card, the growth queue's classification, because the catalog schema has no unknown value; it is not a vendor statement of sign-up terms.

Models​

ModelContextPrice / 1M tokensNotes
deepseek-v4-flash ⭐1M$0.50NeuroLink default. Vendor: "DeepSeek V4 Flash is our default model — fast, cost-effective, and suitable for most tasks."
mimo-v2.5-pro—$1.25NeuroLink fallback. Vendor: "MiMo V2.5 Pro is a powerful model from Xiaomi, recommended for complex reasoning and coding tasks."

Model ids, the 1M context figure and the two prices come from the model table on https://www.lemonfox.ai/apis/chat (retrieved 2026-09-29), whose price column is headed "Price / 1M tokens". The table's context text for deepseek-v4-flash reads "Supports a 1M token context window."; the catalog stores it as 1,000,000 (NeuroLink's decimal reading of "1M"). mimo-v2.5-pro has no context window set. The page also shows the model parameter as "Specify the model ID to be used. Default: deepseek-v4-flash. Also supported: mimo-v2.5-pro."

models.defaultContextWindow (32,768) and models.defaultMaxOutputTokens (4,096) are placeholders the vendor does not publish, for model ids outside the catalog; the page's max_tokens parameter reads "integer, optional, default: infinity". pricingPerMTok is unset on both models because the catalog field takes separate input and output figures and the table has the one "Price / 1M tokens" column.

Each model's vision flag is false in the catalog, a placeholder for a boolean the schema requires; it is not a vendor statement. Each model's status is production, a value the schema requires.

Deprecated models: a second table on the same page, under the heading "Deprecated models", lists llama-8b-chat ("Deprecated. Llama 3.1 8B — use deepseek-v4-flash instead.", $0.50) and llama-70b-chat ("Deprecated. Llama 3.3 70B — use mimo-v2.5-pro instead.", $1.25). These two ids are not in this catalog.

Fallback order when the default is unavailable: deepseek-v4-flash → mimo-v2.5-pro.

Verification status​

Tier-2 onboarding requires evidence before a provider is accepted, and pnpm run verify:provider-onboarding gates it in CI. This is what the catalog currently records for Lemonfox AI — docs-verified only, not live-verified:

ProbeResult
Rosterunauthenticated GET /v1/models, HTTP 401, 2026-09-29 — no key used; model ids taken from https://www.lemonfox.ai/apis/chat; roster not verified
Billingpublic pages listed under Billing, 2026-09-29 — no signup performed
Auth-failure shapeunauthenticated GETs of /v1/models, /v1/chat/completions and /v1 each answered HTTP 401 with the same JSON body (status 401, error.type invalid_request_error, error.code null, error.message beginning "You didn't provide an API key."); errorRules holds one rule, for status 401; no POST request was sent
Tools / structured outputnot declared: the parameter list on https://www.lemonfox.ai/apis/chat is messages, model, max_tokens, stop, stream, frequency_penalty, presence_penalty, temperature and top_p, and no request exercising tools or structured output was sent — structuredOutputWithTools stays false
Live capability sweepnot run. evidence.liveMatrix is null. Before treating this provider as production-ready, run npx tsx test/continuous-test-suite-provider-matrix.ts --provider=lemonfox-ai with a real key and record the result.

Do not treat this entry as equivalent to a live-verified Tier-2 provider (e.g. FriendliAI, Novita AI) until that live matrix has been run and evidence.liveMatrix is filled in.

Troubleshooting​

SymptomCauseFix
HTTP 401The vendor's reply to a request with no key: "You didn't provide an API key. You need to provide your API key in an Authorization header using Bearer auth (i.e. Authorization: Bearer YOUR_KEY)."Set LEMONFOX_AI_API_KEY; keys are at https://lemonfox.ai/apis/keys
llama-8b-chat or llama-70b-chat set as modelThe chat API page lists these ids under "Deprecated models"The page says "use deepseek-v4-flash instead" for llama-8b-chat and "use mimo-v2.5-pro instead" for llama-70b-chat

See also​