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Flatkey Provider Guide

One API key and one balance across 100+ supported AI models

Overview​

Flatkey is a unified gateway that exposes 100+ AI models behind a single OpenAI-compatible endpoint. One API key and one balance cover every supported model, so switching models does not require new accounts, new keys, or new billing setup.

Because Flatkey implements the OpenAI chat-completions specification, it works with NeuroLink's existing openai-compatible provider — no new provider implementation is required.

Key Facts​

Quick Start​

1. Get an API Key​

Create a key at https://console.flatkey.ai/keys.

2. Configure Environment​

Add to .env:

OPENAI_COMPATIBLE_BASE_URL=https://router.flatkey.ai/v1
OPENAI_COMPATIBLE_API_KEY=sk-fk-your-key
OPENAI_COMPATIBLE_MODEL=gpt-4o-mini

3. Verify the Connection​

curl https://router.flatkey.ai/v1/models \
  -H "Authorization: Bearer $FLATKEY_API_KEY"

4. Generate​

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

const ai = new NeuroLink();
const result = await ai.generate({
  provider: "openai-compatible",
  input: { text: "Explain vector databases in two sentences." },
});
console.log(result.content);
npx @juspay/neurolink generate "Hello from Flatkey!" --provider openai-compatible --model "gpt-4o-mini"

Model Discovery​

Flatkey exposes its catalog through the standard endpoint, so NeuroLink's auto-discovery works without extra configuration:

npx @juspay/neurolink models --provider openai-compatible

The full catalog is also browsable at https://flatkey.ai/models.

Configuration Reference​

VariableRequiredDescription
OPENAI_COMPATIBLE_BASE_URLYesFlatkey endpoint — https://router.flatkey.ai/v1
OPENAI_COMPATIBLE_API_KEYYesAPI key from the console
OPENAI_COMPATIBLE_MODELNoDefault model; overridable per request

Flatkey routes to upstream providers, so per-model availability follows the live catalog rather than a fixed list. A machine-readable integration summary is published at https://flatkey.ai/SKILL.md.

Troubleshooting​

401 Unauthorized The key is missing or malformed. Keys start with sk-fk- and are issued at https://console.flatkey.ai/keys. Confirm the value is exported in the environment NeuroLink runs in.

404 on chat completions Check that OPENAI_COMPATIBLE_BASE_URL ends with /v1. The gateway follows the OpenAI path layout, so the version segment is part of the base URL.

Model not found Model IDs must match the live catalog exactly. List what your key can reach:

npx @juspay/neurolink models --provider openai-compatible

Empty or truncated responses Upstream providers apply their own limits. Try a different model from the catalog to isolate whether the behaviour is model-specific.

See Also​