Best AI Gateways for GPT-5.5

OpenRouter is a unified AI inference platform that lets developers connect to a large catalog of models without integrating separately with every model provider. Through one API, users can access models from major AI companies including OpenAI, Google, Anthropic, Meta, Mistral, DeepSeek, Qwen, xAI, and numerous independent providers. The service supports multimodal workloads involving text, images, video, and audio. Developers can use a single account, credit balance, and API key across supported models instead of maintaining separate billing relationships and credentials. OpenRouter's routing infrastructure can prioritize providers based on factors such as price, latency, and reliability. Requests can also be redirected to alternate providers when a preferred endpoint becomes unavailable, helping applications maintain higher uptime. Organizations can configure data policies that restrict prompts to approved models and infrastructure providers. The platform provides benchmarks, model rankings, usage information, documentation, and developer tools for evaluating and deploying different models. OpenRouter is OpenAI API compatible, making it easier for teams to add broad model access to existing AI applications with limited integration changes.

Vercel AI Gateway is a centralized AI model routing and infrastructure platform designed to help developers build, deploy, and scale AI-powered applications using a single unified interface for multiple AI providers and models. The platform enables developers to access text, image, and video generation models from leading AI labs including OpenAI, Anthropic, xAI, and other providers through one API endpoint, one authentication layer, and one management dashboard. AI Gateway simplifies AI application development by consolidating model routing, usage monitoring, billing, failover management, and observability into a single system, eliminating the need to integrate separately with multiple AI vendors. Developers can use the Vercel AI SDK or OpenAI-compatible APIs to build AI applications with support for streaming responses, stateful agents, multimodal generation, tool calling, and conversational workflows. The platform includes built-in resiliency features such as automatic provider failovers and workload routing to maintain uptime during outages or degraded model performance. AI Gateway also provides unified cost tracking and transparent billing with no markup over provider pricing, helping teams monitor AI usage across applications and providers more effectively. In addition to text generation, the platform supports image generation and editing workflows, as well as production-ready AI video generation capabilities accessible through prompt-based interfaces. Integrated developer tooling, SDKs for multiple programming languages, authentication management, and deployment workflows make Vercel AI Gateway particularly suited for modern web applications, AI agents, SaaS platforms, and developer-focused AI products.

Cloudflare AI Gateway serves as an advanced control plane for AI applications, designed to seamlessly connect to various models while dynamically managing request routing, usage tracking, billing, and logging through a single, cohesive interface. This platform empowers teams by providing enhanced visibility and oversight of their AI applications, enabling them to analyze user interactions through detailed analytics and logs, as well as efficiently manage application scalability through features like caching, rate limiting, request retries, and model fallback. By utilizing response caching and minimizing redundant API calls, AI Gateway effectively lowers costs and reduces latency, allowing frequent requests to be fulfilled directly from Cloudflare’s cache rather than relying on the original model provider. Additionally, it boosts reliability with adaptable controls that determine the timing and conditions under which model provider APIs are accessed, guided by various factors such as attributes, fallbacks, latency, cost, and availability. Importantly, routing rules can be modified directly from the dashboard or via API calls without necessitating redeployments or causing any service interruptions, ensuring a smooth operational experience. In this way, organizations can optimize their AI app performance while maintaining flexibility and control.

AIHubMix serves as an all-encompassing API routing platform for AI models, granting users access to prominent language and multimodal models via a single, streamlined interface. By adhering to the OpenAI API format, it enables developers to utilize an API key and a forwarding base URL for AIHubMix, facilitating effortless transitions between various models by merely adjusting the model ID. This service accommodates OpenAI-compatible, Anthropic-compatible, and native Google Gemini interfaces, thereby simplifying the process of transitioning existing applications and leveraging different provider SDKs without the need for extensive integration modifications. The extensive model catalog includes features such as text generation, reasoning, coding capabilities, visual processing, web searching, deep searching, as well as image and video creation, 3D model generation, text-to-speech and speech-to-text conversions, embeddings, reranking, structured output generation, moderation tools, and prompt caching. Users can filter model metadata by criteria like type, input modality, capability, context length, and coding suitability, aiding teams in selecting the most fitting model for their specific needs. This versatility ensures that developers can efficiently adapt to future advancements in AI technology.

FastRouter serves as a comprehensive API gateway designed to facilitate AI applications in accessing a variety of large language, image, and audio models (such as GPT-5, Claude 4 Opus, Gemini 2.5 Pro, and Grok 4) through a streamlined OpenAI-compatible endpoint. Its automatic routing capabilities intelligently select the best model for each request by considering important factors like cost, latency, and output quality, ensuring optimal performance. Additionally, FastRouter is built to handle extensive workloads without any imposed query per second limits, guaranteeing high availability through immediate failover options among different model providers. The platform also incorporates robust cost management and governance functionalities, allowing users to establish budgets, enforce rate limits, and designate model permissions for each API key or project. Real-time analytics are provided, offering insights into token utilization, request frequencies, and spending patterns. Furthermore, the integration process is remarkably straightforward; users simply need to replace their OpenAI base URL with FastRouter’s endpoint while configuring their preferences in the user-friendly dashboard, allowing the routing, optimization, and failover processes to operate seamlessly in the background. This ease of use, combined with powerful features, makes FastRouter an indispensable tool for developers seeking to maximize the efficiency of their AI applications.

Cheaper Inference serves as an API gateway compatible with OpenAI, enabling users to access various AI models from different providers through a unified API key, thus eliminating the need for any changes in request formatting. Developers have the flexibility to switch providers simply by updating the base URL and API key while retaining the same model, messages, tools, streaming configurations, and response management. This service accommodates both text and image models, facilitates vision-enabled chat requests, offers streaming capabilities, includes prompt caching, provides reasoning controls, and allows temporary image uploads for more extensive vision data. Each request can have its model selected individually, and users can filter the catalog based on model type, vision capabilities, reasoning options, streaming availability, or provider identity. The system includes automatic retries to manage network disruptions and provider errors, with fallback routes available for eligible requests to prevent failures. Additionally, every request is documented in the History section, allowing teams to track request volume, token consumption, and overall operational activity, ensuring comprehensive oversight and management of AI interactions. This transparency assists in optimizing usage and understanding patterns over time.

Pioneer serves as an inference API designed for developers who prioritize deployment over managing a GPU cluster. This tool allows teams to connect an existing client, such as OpenAI or Anthropic, to Pioneer, enabling them to maintain their API and code while performing inference seamlessly, all while Pioneer identifies areas where the current model may be lacking. It intelligently groups production traffic based on use cases, highlights opportunities for enhancement in accuracy, latency, or cost, and automatically creates and directs requests to specialized models. Through its continuous improvement mechanism known as Adaptive Inference, Pioneer analyzes real-time production failures to extract valuable examples, retrains a tailored model, assesses the updated checkpoint, and implements enhancements without necessitating any redeployment, all while maintaining access through the same endpoint. Additionally, Pioneer accommodates encoder models for tasks that require structured extraction, including named entity recognition, text classification, structured JSON extraction, privacy filtering, and safety classification, as well as decoder models that facilitate text generation, classification, and open-ended prompting. As a result, developers can optimize their workflows and enhance model performance with minimal hassle.

OfoxAI serves as a comprehensive API gateway compatible with OpenAI, allowing developers and teams to seamlessly access over 100 large language models—including GPT, Claude, Gemini, and DeepSeek—through a single endpoint and one API key. Say goodbye to the hassle of managing multiple accounts, SDKs, and invoices: with OfoxAI, you can integrate once, switch between models with ease, and expand from a single prototype to a full-fledged production team effortlessly. Key features include: One API Key, Access to 100+ Models — Stay current with the latest offerings from OpenAI, Anthropic, Google, DeepSeek, and others. Three Native Protocols — Full compatibility with OpenAI, Anthropic, and Gemini SDKs, enabling seamless transitions without code alteration—just change the base URL. Low-Latency Access — Benefit from global routing with an average latency of under 300ms for quick response times. Zero Markup Pricing — Enjoy transparent pricing, paying only the standard rates set by the official providers, free from hidden fees or surcharges. Built for Teams — Utilize a shared billing dashboard, track usage by each member, and implement budget controls effectively. Flexible Payment Options — OfoxAI accommodates various payment methods, including credit cards, PayPal, and other major regional options for convenience and accessibility. Plus, its user-friendly interface ensures that teams of all sizes can navigate the platform with ease.