Provider & Model Management

When you work with multiple providers and models, it is often desirable to manage them in a central place and access the models through simple string ids.

The AI SDK offers custom providers and a provider registry for this purpose:

With custom providers, you can pre-configure model settings, provide model name aliases, and limit the available models.
The provider registry lets you mix multiple providers and access them through simple string ids.

You can mix and match custom providers, the provider registry, and middleware in your application.

Custom Providers

You can create a custom provider using customProvider.

Example: custom model settings

You might want to override the default model settings for a provider or provide model name aliases with pre-configured settings.

import {
  gateway,
  customProvider,
  defaultSettingsMiddleware,
  wrapLanguageModel,
} from 'ai';

// custom provider with different provider options:
export const openai = customProvider({
  languageModels: {
    // replacement model with custom provider options:
    'gpt-5.1': wrapLanguageModel({
      model: gateway('openai/gpt-5.1'),
      middleware: defaultSettingsMiddleware({
        settings: {
          providerOptions: {
            openai: {
              reasoningEffort: 'high',
            },
          },
        },
      }),
    }),
    // alias model with custom provider options:
    'gpt-5.1-high-reasoning': wrapLanguageModel({
      model: gateway('openai/gpt-5.1'),
      middleware: defaultSettingsMiddleware({
        settings: {
          providerOptions: {
            openai: {
              reasoningEffort: 'high',
            },
          },
        },
      }),
    }),
  },
  fallbackProvider: gateway,
});

Example: model name alias

You can also provide model name aliases, so you can update the model version in one place in the future:

import { customProvider, gateway } from 'ai';

// custom provider with alias names:
export const anthropic = customProvider({
  languageModels: {
    opus: gateway('anthropic/claude-opus-4.1'),
    sonnet: gateway('anthropic/claude-sonnet-4.5'),
    haiku: gateway('anthropic/claude-haiku-4.5'),
  },
  fallbackProvider: gateway,
});

Example: limit available models

You can limit the available models in the system, even if you have multiple providers.

import {
  customProvider,
  defaultSettingsMiddleware,
  wrapLanguageModel,
  gateway,
} from 'ai';

export const myProvider = customProvider({
  languageModels: {
    'text-medium': gateway('anthropic/claude-3-5-sonnet-20240620'),
    'text-small': gateway('openai/gpt-5-mini'),
    'reasoning-medium': wrapLanguageModel({
      model: gateway('openai/gpt-5.1'),
      middleware: defaultSettingsMiddleware({
        settings: {
          providerOptions: {
            openai: {
              reasoningEffort: 'high',
            },
          },
        },
      }),
    }),
    'reasoning-fast': wrapLanguageModel({
      model: gateway('openai/gpt-5.1'),
      middleware: defaultSettingsMiddleware({
        settings: {
          providerOptions: {
            openai: {
              reasoningEffort: 'low',
            },
          },
        },
      }),
    }),
  },
  embeddingModels: {
    embedding: gateway.embeddingModel('openai/text-embedding-3-small'),
  },
  // no fallback provider
});

Provider Registry

You can create a provider registry with multiple providers and models using createProviderRegistry.

Setup

import { anthropic } from '@ai-sdk/anthropic';
import { openai } from '@ai-sdk/openai';
import { createProviderRegistry, gateway } from 'ai';

export const registry = createProviderRegistry({
  // register provider with prefix and default setup using gateway:
  gateway,

  // register provider with prefix and direct provider import:
  anthropic,
  openai,
});

Setup with Custom Separator

By default, the registry uses : as the separator between provider and model IDs. You can customize this separator:

import { anthropic } from '@ai-sdk/anthropic';
import { openai } from '@ai-sdk/openai';
import { createProviderRegistry, gateway } from 'ai';

export const customSeparatorRegistry = createProviderRegistry(
  {
    gateway,
    anthropic,
    openai,
  },
  { separator: ' > ' },
);

Example: Use language models

You can access language models by using the languageModel method on the registry. The provider id will become the prefix of the model id: providerId:modelId.

import { generateText } from 'ai';
import { registry } from './registry';

const { text } = await generateText({
  model: registry.languageModel('openai:gpt-5.1'), // default separator
  // or with custom separator:
  // model: customSeparatorRegistry.languageModel('openai > gpt-5.1'),
  prompt: 'Invent a new holiday and describe its traditions.',
});

Example: Use text embedding models

You can access text embedding models by using the .embeddingModel method on the registry. The provider id will become the prefix of the model id: providerId:modelId.

import { embed } from 'ai';
import { registry } from './registry';

const { embedding } = await embed({
  model: registry.embeddingModel('openai:text-embedding-3-small'),
  value: 'sunny day at the beach',
});

Example: Use image models

You can access image models by using the imageModel method on the registry. The provider id will become the prefix of the model id: providerId:modelId.

import { generateImage } from 'ai';
import { registry } from './registry';

const { image } = await generateImage({
  model: registry.imageModel('openai:dall-e-3'),
  prompt: 'A beautiful sunset over a calm ocean',
});

Combining Custom Providers, Provider Registry, and Middleware

The central idea of provider management is to set up a file that contains all the providers and models you want to use. You may want to pre-configure model settings, provide model name aliases, limit the available models, and more.

Here is an example that implements the following concepts:

pass through gateway with a namespace prefix (here: gateway > *)
pass through a full provider with a namespace prefix (here: xai > *)
setup an OpenAI-compatible provider with custom api key and base URL (here: custom > *)
setup model name aliases (here: anthropic > fast, anthropic > writing, anthropic > reasoning)
pre-configure model settings (here: anthropic > reasoning)
validate the provider-specific options (here: AnthropicLanguageModelOptions)
use a fallback provider (here: anthropic > *)
limit a provider to certain models without a fallback (here: groq > gemma2-9b-it, groq > qwen-qwq-32b)
define a custom separator for the provider registry (here: >)

import { anthropic, AnthropicLanguageModelOptions } from '@ai-sdk/anthropic';
import { createOpenAICompatible } from '@ai-sdk/openai-compatible';
import { xai } from '@ai-sdk/xai';
import { groq } from '@ai-sdk/groq';
import {
  createProviderRegistry,
  customProvider,
  defaultSettingsMiddleware,
  gateway,
  wrapLanguageModel,
} from 'ai';

export const registry = createProviderRegistry(
  {
    // pass through gateway with a namespace prefix
    gateway,

    // pass through full providers with namespace prefixes
    xai,

    // access an OpenAI-compatible provider with custom setup
    custom: createOpenAICompatible({
      name: 'provider-name',
      apiKey: process.env.CUSTOM_API_KEY,
      baseURL: 'https://api.custom.com/v1',
    }),

    // setup model name aliases
    anthropic: customProvider({
      languageModels: {
        fast: anthropic('claude-haiku-4-5'),

        // simple model
        writing: anthropic('claude-sonnet-4-5'),

        // extended reasoning model configuration:
        reasoning: wrapLanguageModel({
          model: anthropic('claude-sonnet-4-5'),
          middleware: defaultSettingsMiddleware({
            settings: {
              maxOutputTokens: 100000, // example default setting
              providerOptions: {
                anthropic: {
                  thinking: {
                    type: 'enabled',
                    budgetTokens: 32000,
                  },
                } satisfies AnthropicLanguageModelOptions,
              },
            },
          }),
        }),
      },
      fallbackProvider: anthropic,
    }),

    // limit a provider to certain models without a fallback
    groq: customProvider({
      languageModels: {
        'gemma2-9b-it': groq('gemma2-9b-it'),
        'qwen-qwq-32b': groq('qwen-qwq-32b'),
      },
    }),
  },
  { separator: ' > ' },
);

// usage:
const model = registry.languageModel('anthropic > reasoning');

Global Provider Configuration

The AI SDK 5 includes a global provider feature that allows you to specify a model using just a plain model ID string:

import { streamText } from 'ai';
__PROVIDER_IMPORT__;

const result = await streamText({
  model: __MODEL__, // Uses the global provider (defaults to gateway)
  prompt: 'Invent a new holiday and describe its traditions.',
});

By default, the global provider is set to the Vercel AI Gateway.

Customizing the Global Provider

You can set your own preferred global provider:

import { openai } from '@ai-sdk/openai';

// Initialize once during startup:
globalThis.AI_SDK_DEFAULT_PROVIDER = openai;

import { streamText } from 'ai';

const result = await streamText({
  model: 'gpt-5.1', // Uses OpenAI provider without prefix
  prompt: 'Invent a new holiday and describe its traditions.',
});

This simplifies provider usage and makes it easier to switch between providers without changing your model references throughout your codebase.