Vercel AI SDK - NexLLM

Last edited: 25 Oct 2026 (Asia/Hong_Kong) Point the Vercel AI SDK at NexLLM’s OpenAI-compatible gateway. Chat and streaming use @ai-sdk/openai. Images use the published @nexllm/ai-sdk-provider package (0.1.0) with AI SDK generateImage / experimental_generateImage.

Already migrating off Vercel AI Gateway? Follow Migrate from Vercel AI Gateway for env vars, model IDs, and gateway-option cleanup. This page is the Integrations setup for new apps and for using NexLLM as your AI SDK backend.

Introduction

NexLLM is an OpenAI-compatible inference gateway at https://www.nexllm.ai/v1.

Capability	Status on NexLLM
`generateText` / `streamText` (Chat Completions)	Ready — `createOpenAI` + `.chat(modelId)`
Model discovery	Ready — `GET /v1/models` with your key
Image generation (`generateImage` via NexLLM provider)	Ready — `@nexllm/ai-sdk-provider@0.1.0` → `nexllm.image(modelId)`
Images via OpenAI SDK / HTTP	Ready — `POST /v1/images/generations` and `/v1/images/edits`
Image edits via the thin AI SDK provider	Not in this package — use OpenAI SDK or HTTP
Embeddings / speech / video via this provider	No — use Compatible APIs or other SDKs

Spend lands on the wallet tied to your API key. There is no Vercel-AI-specific surcharge. If your agent should call NexLLM from Claude or Cursor instead of application code, use the MCP integration.

Prerequisites

A NexLLM account at www.nexllm.ai
An API key from the dashboard (Getting your API keys)
Node.js and a project that uses (or will use) the ai package
Wallet balance for paid inference

Keep NEXLLM_API_KEY server-side. Do not expose it in public Next.js NEXT_PUBLIC_* vars or browser bundles.

Install

Chat only

npm install ai @ai-sdk/openai

Chat + images (recommended)

npm install ai @ai-sdk/openai @nexllm/ai-sdk-provider

Peer dependency for the image provider: ai ^6 (ImageModelV3). Use matching majors for ai and @ai-sdk/openai — do not mix unrelated major upgrades. Package: npmjs.com/package/@nexllm/ai-sdk-provider

Configure environment

export NEXLLM_API_KEY="YOUR_NEXLLM_API_KEY"

# Example only — use an exact id from GET /v1/models for your key
export NEXLLM_MODEL="gpt-4o"
export NEXLLM_IMAGE_MODEL="dall-e-3"

Authentication for OpenAI-compatible requests:

Authorization: Bearer YOUR_NEXLLM_API_KEY

See Authentication.

Chat with the AI SDK

Create an explicit OpenAI provider pointed at NexLLM, then use .chat(modelId) for Chat Completions.

import { createOpenAI } from "@ai-sdk/openai";
import { generateText } from "ai";

const apiKey = process.env.NEXLLM_API_KEY;
const modelId = process.env.NEXLLM_MODEL;

if (!apiKey || !modelId) {
  throw new Error("NEXLLM_API_KEY and NEXLLM_MODEL are required");
}

const nexllmChat = createOpenAI({
  baseURL: "https://www.nexllm.ai/v1",
  apiKey,
});

const { text } = await generateText({
  model: nexllmChat.chat(modelId),
  prompt: "Write a short greeting.",
});

console.log(text);

Use nexllmChat.chat(modelId) when you want Chat Completions. The OpenAI provider’s default model factory can select the Responses API. Do not replace .chat(modelId) with nexllmChat(modelId) unless you intentionally want /v1/responses and have verified the model supports it.

Streaming

import { createOpenAI } from "@ai-sdk/openai";
import { streamText } from "ai";

const nexllmChat = createOpenAI({
  baseURL: "https://www.nexllm.ai/v1",
  apiKey: process.env.NEXLLM_API_KEY,
});

const result = streamText({
  model: nexllmChat.chat(process.env.NEXLLM_MODEL),
  prompt: "Explain NexLLM in one paragraph.",
});

for await (const textPart of result.textStream) {
  process.stdout.write(textPart);
}

In a Next.js Route Handler or Server Action, return result.toDataStreamResponse() (or the streaming helper your AI SDK major documents) the same way you would for any other OpenAI-compatible provider.

Discover model IDs

curl https://www.nexllm.ai/v1/models \
  -H "Authorization: Bearer $NEXLLM_API_KEY"

Use the exact data[].id value in nexllmChat.chat(...) and nexllm.image(...). Do not invent a mapping from another gateway’s prefixed strings. See Models API and Channel groups.

Images with `@nexllm/ai-sdk-provider`

The published package wraps POST /v1/images/generations for AI SDK generateImage / experimental_generateImage. It does not replace @ai-sdk/openai for chat.

Quick start

import { nexllm } from "@nexllm/ai-sdk-provider";
import { experimental_generateImage as generateImage } from "ai";

const { image, images } = await generateImage({
  model: nexllm.image(process.env.NEXLLM_IMAGE_MODEL || "dall-e-3"),
  prompt: "A serene mountain landscape at sunset with a reflecting lake",
  size: "1024x1024",
});

// AI SDK returns binary / base64-backed image objects
console.log("bytes:", image.uint8Array?.byteLength ?? image.base64?.length);

Custom config

import { createNexllm } from "@nexllm/ai-sdk-provider";

const nexllm = createNexllm({
  apiKey: process.env.NEXLLM_API_KEY,
  baseURL: "https://www.nexllm.ai/v1", // default
});

const model = nexllm.image("dall-e-2", { maxImagesPerCall: 4 });

Optional provider options

For GPT Image model IDs (nexllm/gpt-image-*), do not pass response_format (and prefer a provider/path that omits it). The b64_json example below is for models that accept OpenAI Images response_format (for example classic DALL·E-style). Confirm with GET /v1/models plus a cheap probe.

await generateImage({
  model: nexllm.image("dall-e-3"),
  prompt: "A product hero shot on a clean studio background",
  size: "1024x1024",
  providerOptions: {
    nexllm: {
      quality: "hd",
      style: "vivid",
      // default inside the provider is b64_json
      response_format: "b64_json",
    },
  },
});

Confirm image-capable model IDs with GET /v1/models for your key. Full gateway fields: Image Generation API. From an agent (Claude / Cursor), you can also use MCP generate_image — see MCP integration.

Images without the AI SDK provider (fallback)

If your ai major does not expose a compatible image provider interface yet, call the OpenAI SDK or HTTP against the same base URL.

OpenAI SDK

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://www.nexllm.ai/v1",
  apiKey: process.env.NEXLLM_API_KEY,
});

const response = await client.images.generate({
  model: "dall-e-3", // confirm an image model id available to your key
  prompt: "A futuristic cityscape at sunset",
  n: 1,
  size: "1024x1024",
});

console.log(response.data[0]?.url);

Direct HTTP

curl https://www.nexllm.ai/v1/images/generations \
  -H "Authorization: Bearer $NEXLLM_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "dall-e-3",
    "prompt": "A futuristic cityscape at sunset",
    "n": 1,
    "size": "1024x1024"
  }'

Optional: Responses API

If you deliberately need the Responses shape:

const { text } = await generateText({
  model: nexllmChat.responses(modelId), // only after verifying Responses compatibility
  prompt: "Write a short greeting.",
});

Confirm the model’s supported endpoint types first. See API Reference and the Responses notes in Migrate from Vercel AI Gateway.

How billing works

Call path	Billing
AI SDK `generateText` / `streamText` via `/v1/chat/completions`	Standard gateway rates for that model
`@nexllm/ai-sdk-provider` images	Standard gateway rates for that image model
OpenAI SDK / HTTP images	Same wallet rates
MCP tools from an agent	Same wallet; no MCP surcharge

There is no separate “Vercel AI” price list. See Pricing overview and Wallet.

Troubleshooting

Requests still go to Vercel AI Gateway

Search the repo for @ai-sdk/gateway, gateway(, AI_GATEWAY_API_KEY, and ai-gateway.vercel.sh. Replace migrated call sites with createOpenAI({ baseURL: "https://www.nexllm.ai/v1", ... }) and .chat(modelId). Check shared registries and background jobs, not only the main route.

The AI SDK hits /responses unexpectedly

Use model: nexllmChat.chat(modelId) for Chat Completions. The default OpenAI provider factory may select Responses.

Model not found

Call GET /v1/models with the same key the app uses. Confirm the exact id, the key’s channel group, and any model restrictions on the key.

Authentication fails

Send a NexLLM key in NEXLLM_API_KEY, not a Vercel gateway key or OIDC token. Check expiration, IP allowlist, and whitespace. See Authentication.

generateImage fails or package not found

Install @nexllm/ai-sdk-provider (and ai ^6). Confirm the image model ID is available to your key. For edits (/v1/images/edits), use the OpenAI SDK — the thin provider only wraps generations.

Migrate from Vercel AI Gateway — full cutover checklist
Compatible APIs — OpenAI-compatible gateway overview
MCP integration — agents instead of app code
Skills — outcome recipes on top of MCP
API Reference — all gateway endpoints
Getting your API keys

​Introduction

​Prerequisites

​Install

​Chat only

​Chat + images (recommended)

​Configure environment

​Chat with the AI SDK

​Streaming

​Discover model IDs

​Images with @nexllm/ai-sdk-provider

​Quick start

​Custom config

​Optional provider options

​Images without the AI SDK provider (fallback)

​OpenAI SDK

​Direct HTTP

​Optional: Responses API

​How billing works

​Troubleshooting

​Related

Introduction

Prerequisites

Install

Chat only

Chat + images (recommended)

Configure environment

Chat with the AI SDK

Streaming

Discover model IDs

Images with `@nexllm/ai-sdk-provider`

Quick start

Custom config

Optional provider options

Images without the AI SDK provider (fallback)

OpenAI SDK

Direct HTTP

Optional: Responses API

How billing works

Troubleshooting

Related