--- title: SDKs & APIs product: vercel url: /docs/ai-gateway/sdks-and-apis canonical_url: "https://vercel.com/docs/ai-gateway/sdks-and-apis" last_updated: 2026-07-30 type: conceptual prerequisites: - /docs/ai-gateway related: - /docs/ai-gateway/authentication-and-byok - /docs/ai-gateway/models-and-providers/provider-filtering-and-ordering - /docs/ai-gateway/models-and-providers/model-fallbacks - /docs/ai-gateway/observability-and-spend/observability - /docs/ai-gateway/observability-and-spend/budgets summary: Use the AI Gateway with various SDKs and API specifications including OpenAI, Anthropic, and OpenResponses. install_vercel_plugin: npx plugins add vercel/vercel-plugin --- # SDKs & APIs AI Gateway provides drop-in compatible APIs that let you switch by changing a base URL. No code rewrites required. Use the same SDKs and tools you already know, with access to 200+ models from every major provider. ## Quick start Point your existing SDK to the gateway: #### AI SDK ```bash package-manager npm i ai ``` ```typescript import { generateText } from 'ai'; const { text } = await generateText({ model: 'anthropic/claude-opus-5', prompt: 'Hello!', }); ``` #### Chat Completions ```typescript import OpenAI from 'openai'; const client = new OpenAI({ apiKey: process.env.AI_GATEWAY_API_KEY, baseURL: 'https://ai-gateway.vercel.sh/v1', }); const response = await client.chat.completions.create({ model: 'anthropic/claude-opus-5', messages: [{ role: 'user', content: 'Hello!' }], }); ``` #### OpenAI Responses ```typescript import OpenAI from 'openai'; const client = new OpenAI({ apiKey: process.env.AI_GATEWAY_API_KEY, baseURL: 'https://ai-gateway.vercel.sh/v1', }); const response = await client.responses.create({ model: 'anthropic/claude-opus-5', input: 'Hello!', }); ``` #### Anthropic Messages ```typescript import Anthropic from '@anthropic-ai/sdk'; const client = new Anthropic({ apiKey: process.env.AI_GATEWAY_API_KEY, baseURL: 'https://ai-gateway.vercel.sh', }); const message = await client.messages.create({ model: 'anthropic/claude-opus-5', max_tokens: 1024, messages: [{ role: 'user', content: 'Hello!' }], }); ``` #### OpenResponses ```typescript const response = await fetch('https://ai-gateway.vercel.sh/v1/responses', { method: 'POST', headers: { 'Content-Type': 'application/json', Authorization: `Bearer ${process.env.AI_GATEWAY_API_KEY}`, }, body: JSON.stringify({ model: 'anthropic/claude-opus-5', input: [{ type: 'message', role: 'user', content: 'Hello!' }], }), }); ``` ## What every surface shares The surfaces below differ in request shape, not in what the gateway does with the request. Whichever you pick: - **Authentication is the same.** An AI Gateway [API key or Vercel OIDC token](/docs/ai-gateway/authentication-and-byok) authenticates every surface. Anthropic Messages also accepts the key in `x-api-key`. - **Model IDs are the same.** Every surface takes `provider/model` slugs like `anthropic/claude-opus-5`. Browse them in the [model list](/ai-gateway/models). - **Routing, fallbacks, and BYOK are the same.** [Provider ordering](/docs/ai-gateway/models-and-providers/provider-filtering-and-ordering), [model fallbacks](/docs/ai-gateway/models-and-providers/model-fallbacks), and [your own provider keys](/docs/ai-gateway/authentication-and-byok) apply regardless of surface. - **Observability is the same.** Requests land in [AI Gateway observability](/docs/ai-gateway/observability-and-spend/observability) with the same fields and count against the same [budgets](/docs/ai-gateway/observability-and-spend/budgets). Switching surfaces is a client-side change. It does not change your billing, your keys, or which providers you reach. ## Why use these APIs? - **No vendor lock-in**: Switch between Claude, GPT, Gemini, and other models without changing your code - **Unified billing**: One invoice for all providers instead of managing multiple accounts - **Built-in fallbacks**: Automatic retry with alternative providers if one fails - **Streaming support**: Real-time responses with SSE across all compatible endpoints - **Full feature parity**: Tool calling, structured outputs, vision, and embeddings work exactly as documented ## Available APIs | API | Best for | Documentation | | ------------------------------------------------------------------------------------- | -------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [AI SDK](/docs/ai-gateway/sdks-and-apis/ai-sdk) (recommended) | Normalizes provider differences, works with AI Gateway automatically | [Streaming](/docs/ai-gateway/sdks-and-apis/ai-sdk#streaming), [Structured outputs](/docs/ai-gateway/sdks-and-apis/ai-sdk#structured-outputs), [Tools](/docs/ai-gateway/sdks-and-apis/ai-sdk#tool-calling) | | [OpenAI Responses API](/docs/ai-gateway/sdks-and-apis/responses) | OpenAI Responses API users | [Streaming](/docs/ai-gateway/sdks-and-apis/responses/streaming), [Tools](/docs/ai-gateway/sdks-and-apis/responses/tool-calling), [Structured output](/docs/ai-gateway/sdks-and-apis/responses/structured-outputs) | | [OpenAI Chat Completions API](/docs/ai-gateway/sdks-and-apis/openai-chat-completions) | Existing OpenAI integrations, broad language support | [Chat](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/chat-completions), [Tools](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/tool-calling), [Embeddings](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/embeddings) | | [Anthropic Messages API](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api) | Claude Code, Anthropic SDK users | [Messages](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api/messages), [Tools](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api/tool-calling), [Images](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api/images) | | [OpenResponses](/docs/ai-gateway/sdks-and-apis/openresponses) | New projects, provider-agnostic design | [Streaming](/docs/ai-gateway/sdks-and-apis/openresponses/streaming), [Tools](/docs/ai-gateway/sdks-and-apis/openresponses/tool-calling), [Images](/docs/ai-gateway/sdks-and-apis/openresponses/images) | | [Cohere Rerank API](/docs/ai-gateway/sdks-and-apis/cohere-rerank) | Reranking documents with the Cohere SDK or plain HTTP | [Rerank](/docs/ai-gateway/sdks-and-apis/cohere-rerank#supported-endpoints), [Provider routing](/docs/ai-gateway/sdks-and-apis/cohere-rerank#provider-routing) | | [AI SDK for Python](/docs/ai-gateway/sdks-and-apis/ai-sdk-python) (public beta) | Python apps and agents with a native SDK | [Quick start](/docs/ai-gateway/sdks-and-apis/ai-sdk-python#quick-start), [Tools](/docs/ai-gateway/sdks-and-apis/ai-sdk-python#tool-calling-with-agents) | | [Python](/docs/ai-gateway/sdks-and-apis/python) | Python developers | [Async](/docs/ai-gateway/sdks-and-apis/python#async-support), [Streaming](/docs/ai-gateway/sdks-and-apis/python#streaming), [Frameworks](/docs/ai-gateway/sdks-and-apis/python#framework-integrations) | ## Capability coverage Every cell links to that surface's page for the topic: | Capability | AI SDK | Chat Completions | OpenAI Responses | Anthropic Messages | OpenResponses | | ------------------ | ------------------------------------------------------------------ | ------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------- | | Text generation | [Quick start](/docs/ai-gateway/sdks-and-apis/ai-sdk#quick-start) | [Chat completions](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/chat-completions) | [Text generation](/docs/ai-gateway/sdks-and-apis/responses/text-generation) | [Messages](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api/messages) | [Text generation](/docs/ai-gateway/sdks-and-apis/openresponses/text-generation) | | Streaming | [Streaming](/docs/ai-gateway/sdks-and-apis/ai-sdk#streaming) | [Streaming](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/streaming) | [Streaming](/docs/ai-gateway/sdks-and-apis/responses/streaming) | [Streaming](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api/streaming) | [Streaming](/docs/ai-gateway/sdks-and-apis/openresponses/streaming) | | Tool calling | [Tool calling](/docs/ai-gateway/sdks-and-apis/ai-sdk#tool-calling) | [Tool calling](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/tool-calling) | [Tool calling](/docs/ai-gateway/sdks-and-apis/responses/tool-calling) | [Tool calling](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api/tool-calling) | [Tool calling](/docs/ai-gateway/sdks-and-apis/openresponses/tool-calling) | | Structured outputs | [Structured outputs](/docs/ai-gateway/sdks-and-apis/ai-sdk#structured-outputs) | [Structured outputs](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/structured-outputs) | [Structured outputs](/docs/ai-gateway/sdks-and-apis/responses/structured-outputs) | [Structured outputs](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api/structured-outputs) | [Structured outputs](/docs/ai-gateway/sdks-and-apis/openresponses/structured-outputs) | | Reasoning | [Reasoning](/docs/ai-gateway/sdks-and-apis/ai-sdk#reasoning) | [Reasoning](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/reasoning) | [Reasoning](/docs/ai-gateway/sdks-and-apis/responses/reasoning) | [Extended thinking](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api/reasoning) | [Reasoning](/docs/ai-gateway/sdks-and-apis/openresponses/reasoning) | | Image input | [AI SDK docs](https://ai-sdk.dev/docs/foundations/prompts#image-parts) | [File attachments](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/images) | [Images](/docs/ai-gateway/sdks-and-apis/responses/images) | [File attachments](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api/images) | [Images](/docs/ai-gateway/sdks-and-apis/openresponses/images) | Two capabilities are surface-specific rather than shared: [embeddings](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/embeddings) and [image generation](/docs/ai-gateway/sdks-and-apis/openai-chat-completions/image-generation) are only on Chat Completions, and [reranking](/docs/ai-gateway/sdks-and-apis/cohere-rerank) is only on the Cohere Rerank API. Whether a given model supports a capability is a separate question from whether the surface exposes it. Check the [model list](/ai-gateway/models) for per-model support. ## Choosing an API - **New project?** Use [AI SDK](/docs/ai-gateway/sdks-and-apis/ai-sdk). It handles provider differences for you and supports streaming, structured outputs, tool calling, and reasoning across all providers. - **Writing Python?** Use the [AI SDK for Python](/docs/ai-gateway/sdks-and-apis/ai-sdk-python) (public beta), or point the official [OpenAI and Anthropic Python SDKs](/docs/ai-gateway/sdks-and-apis/python) at AI Gateway. - **Using the OpenAI SDK?** The [OpenAI Responses API](/docs/ai-gateway/sdks-and-apis/responses) and [Chat Completions API](/docs/ai-gateway/sdks-and-apis/openai-chat-completions) both work by changing your base URL. - **Using Claude Code or the Anthropic SDK?** Use the [Anthropic Messages API](/docs/ai-gateway/sdks-and-apis/anthropic-messages-api) for native feature support. - **Want a provider-agnostic REST API?** Use [OpenResponses](/docs/ai-gateway/sdks-and-apis/openresponses). ## Next steps - [Get your API key](/docs/ai-gateway/authentication-and-byok) to start making requests - [Browse available models](/docs/ai-gateway/models-and-providers) to find the right model for your use case - [Set up observability](/docs/ai-gateway/observability-and-spend/observability) to monitor usage and debug requests --- [View full sitemap](/docs/sitemap)