Inkling vs. GPT-Realtime-2.1

Inkling is an open-weights multimodal AI model from Thinking Machines built to support customization, agentic workflows, coding, reasoning, vision, audio, and enterprise AI use cases. The model is a Mixture-of-Experts transformer with 975 billion total parameters, 41 billion active parameters, 256 routed experts per MoE layer, and six routed experts active per token. It supports context windows up to 1 million tokens and was pretrained on 45 trillion tokens across text, images, audio, and video. Inkling is designed as a broad foundation model rather than a narrowly optimized benchmark model, giving it balanced capabilities across reasoning, coding, factuality, instruction following, vision, audio, tool use, and safety. Its controllable thinking effort lets developers adjust how much computation and generated reasoning the model uses, helping teams balance quality, latency, and cost for different production needs. The model can run agentic coding tasks, use tools, create web apps, generate polished multi-page artifacts, reason over long contexts, and work through iterative refinement loops. For multimodal tasks, Inkling can process images, answer questions about visual content, transcribe and reason over audio, follow spoken instructions, and combine visual reasoning with code-based tools such as Python. Thinking Machines trained Inkling for calibration, instruction following, factual reliability, refusal behavior, and safety across multiple modalities, including evaluations for dangerous capabilities and human-AI threat vectors. Inkling is available on Tinker for fine-tuning, with 64K and 256K context options, an Inkling Playground for testing, cookbook recipes, and support for multimodal post-training workflows. Its full weights are available on Hugging Face, and deployment support is available through APIs and infrastructure partners such as TogetherAI, Fireworks, Modal, Databricks, Baseten, SGLang, vLLM, llama.cpp, and transformers.

GPT-Realtime-2.1 is an OpenAI realtime reasoning model for developers building voice agents, conversational AI assistants, and speech-to-speech applications. The model is designed to support fast interactive experiences where users can speak naturally and receive audio or text responses. GPT-Realtime-2.1 updates GPT-Realtime-2 with improved handling of alphanumeric recognition, silence, background noise, and interruptions. It supports text, audio, and image input, with text and audio output, while video is not supported. The model includes configurable reasoning effort so developers can balance reasoning depth, latency, and token usage for different voice-agent workflows. GPT-Realtime-2.1 also supports instruction following, function calling, tool use, and reasoning tokens for more complex applications. Its 128,000-token context window and 32,000-token maximum output allow it to manage longer conversations and richer task context. OpenAI lists support across endpoints such as Chat Completions, Responses, Realtime, realtime translations, realtime transcription sessions, Assistants, Batch, and related API services. The model’s documented pricing includes $4 per 1 million text input tokens, $0.40 per 1 million cached text input tokens, and $24 per 1 million text output tokens, with separate audio and image token pricing. GPT-Realtime-2.1 is not documented as supporting streaming, structured outputs, fine-tuning, or predicted outputs. By combining realtime speech, multimodal input, reasoning, function calling, and tool use, GPT-Realtime-2.1 gives developers a foundation for building sophisticated AI voice agents and interactive customer-facing applications.