Reasoning Model Support With Extended Thinking

via “sustained multi-step reasoning”

Anthropic's 2026 flagship — strongest Claude for agents, long-horizon coding, and tool orchestration.

Unique: Combines advanced reasoning capabilities with a user-friendly interface, making complex logical tasks accessible.

vs others: More reliable than simpler models that lack depth in reasoning capabilities.

via “extended reasoning with thinking tokens”

Google's multimodal API — Gemini 2.5 Pro/Flash, 1M context, video understanding, grounding.

Unique: Allocates hidden 'thinking tokens' for internal reasoning before generating output, allowing the model to spend additional computation on difficult problems without exposing reasoning steps to the user

vs others: Similar to OpenAI's o1 extended reasoning, but integrated into the standard Gemini API rather than a separate model, allowing extended reasoning on the same multimodal inputs (images, audio, video) that standard Gemini supports

via “thinking-models-and-extended-reasoning-support”

Get up and running with Kimi-K2.5, GLM-5, MiniMax, DeepSeek, gpt-oss, Qwen, Gemma and other models.

Unique: Thinking token handling is integrated into the inference pipeline, not a post-processing step. KV cache management accounts for thinking token overhead, preventing OOM errors when reasoning tokens exceed output tokens by orders of magnitude.

vs others: More transparent than OpenAI's o1 API because thinking tokens are accessible for debugging; more flexible than vLLM because it supports arbitrary thinking token formats without requiring model-specific parsing

via “reasoning-and-extended-thinking-support”

Python SDK, Proxy Server (AI Gateway) to call 100+ LLM APIs in OpenAI (or native) format, with cost tracking, guardrails, loadbalancing and logging. [Bedrock, Azure, OpenAI, VertexAI, Cohere, Anthropic, Sagemaker, HuggingFace, VLLM, NVIDIA NIM]

Unique: Implements provider-agnostic reasoning support by translating reasoning parameters to provider-native formats (OpenAI o1 reasoning, Claude extended thinking), with cost tracking for expensive reasoning tokens and access to reasoning traces for analysis

vs others: Abstracts provider differences in reasoning features, enabling applications to use reasoning models across providers without provider-specific code

via “reasoning-focused model variants with intermediate thinking generation”

Allen AI's fully open and transparent language model.

Unique: Explicit reasoning variants trained with SFT, DPO, and RL stages on thinking data, with full training pipeline reproducibility via Open Instruct. Includes both 32B and 7B scales enabling reasoning research across model sizes. Training data and RL methodology fully documented, allowing researchers to study how preference optimization and RL shape reasoning behavior.

vs others: More transparent than OpenAI o1 (training methodology and data fully released) but lacks published benchmarks on reasoning tasks and inference latency data, making practical performance comparison difficult.

via “extended thinking with user-controlled reasoning effort”

Anthropic's balanced model for production workloads.

Unique: Implements hybrid reasoning with both user-controlled extended thinking and automatic adaptive thinking, allowing fine-grained effort control via API parameters rather than binary on/off toggle. This dual-mode approach enables cost optimization by letting developers choose reasoning depth per-request while maintaining automatic reasoning for complex queries.

vs others: Offers more granular reasoning control than GPT-4o's reasoning mode (which lacks effort parameters) and lower cost than o1 models while maintaining competitive reasoning performance on complex tasks.

via “doctoral-level scientific reasoning and analysis”

OpenAI's most powerful reasoning model for complex problems.

Unique: Applies extended reasoning to scientific problem-solving with domain-specific reasoning about physical laws, chemical reactions, biological systems, and interdisciplinary connections — reasoning depth enables synthesis across domains rather than isolated problem-solving

vs others: Handles doctoral-level science questions with reasoning that integrates domain knowledge and explores competing explanations, outperforming GPT-4 on complex scientific reasoning by allocating more compute to understanding problem structure and constraints

via “native chain-of-thought reasoning with extended thinking”

Google's most capable model with 1M context and native thinking.

Unique: Native thinking is baked into model architecture rather than achieved through prompt engineering; enables 94.3% accuracy on GPQA Diamond (scientific knowledge) without requiring explicit CoT prompting, and 77.1% on ARC-AGI-2 abstract reasoning puzzles

vs others: Outperforms GPT-4 and Claude 3.5 on reasoning benchmarks (GPQA 94.3% vs Sonnet 89.9%) because thinking is a first-class architectural feature, not a post-hoc prompt technique

via “reasoning model output parsing with thinking extraction”

OpenAI and Anthropic compatible server for Apple Silicon. Run LLMs and vision-language models (Llama, Qwen-VL, LLaVA) with continuous batching, MCP tool calling, and multimodal support. Native MLX backend, 400+ tok/s. Works with Claude Code.

Unique: Parses and separates thinking tokens from final output during streaming, enabling real-time access to model reasoning without waiting for generation completion; supports multiple reasoning formats with configurable parsing strategies

vs others: More transparent than black-box reasoning (exposes thinking process); enables streaming reasoning display unlike batch-only parsing; supports multiple model formats

An VS Code ChatGPT Copilot Extension

Unique: Treats reasoning models as first-class providers in the provider selection UI, allowing users to switch to o1/o3/DeepSeek R1 with the same configuration flow as standard models. Handles provider-specific restrictions (no system prompts, limited tool calling) transparently.

vs others: Provides access to reasoning models within the editor without separate tools or workflows, though reasoning models themselves are slower and more expensive than standard models, making them suitable only for complex problems.

via “reasoning-model-support-with-extended-thinking”

Chat via OpenAI-Compatible API

Unique: Transparently supports reasoning models (o1, o3-mini, DeepSeek R1) with extended thinking capabilities, routing complex problems to models optimized for deep reasoning; handles different token accounting and response time characteristics

vs others: Enables access to state-of-the-art reasoning capabilities without custom integration; more cost-effective than running reasoning models locally; better for complex problems than standard fast models

via “extended-reasoning-with-internal-thinking”

Gemini 2.5 Pro is Google’s state-of-the-art AI model designed for advanced reasoning, coding, mathematics, and scientific tasks. It employs “thinking” capabilities, enabling it to reason through responses with enhanced accuracy...

Unique: Implements internalized thinking as part of the inference architecture rather than exposing chain-of-thought tokens, allowing the model to reason without token overhead while maintaining response quality. Uses adaptive computation allocation to balance reasoning depth with response latency based on problem complexity.

vs others: Provides reasoning benefits of extended chain-of-thought without the token cost and latency of explicit reasoning tokens, differentiating it from models like o1 that expose reasoning in the output stream.

via “extended reasoning with native thinking mode”

Gemini 2.5 Flash is Google's state-of-the-art workhorse model, specifically designed for advanced reasoning, coding, mathematics, and scientific tasks. It includes built-in "thinking" capabilities, enabling it to provide responses with greater...

Unique: Integrates reasoning as a first-class inference primitive rather than a prompt engineering technique, using an internal thinking phase that explores solution spaces before output generation, with separate token accounting for transparency

vs others: Provides more reliable reasoning than prompt-based CoT approaches (like o1-preview) while maintaining faster inference than full-chain reasoning models, with explicit visibility into thinking token usage

via “extended-reasoning-with-thinking-tokens”

Gemini 2.5 Pro is Google’s state-of-the-art AI model designed for advanced reasoning, coding, mathematics, and scientific tasks. It employs “thinking” capabilities, enabling it to reason through responses with enhanced accuracy...

Unique: Uses hidden thinking tokens that consume inference budget but remain invisible to users, enabling internal verification and multi-path exploration without exposing intermediate steps — distinct from chain-of-thought which exposes all reasoning to the user

vs others: Provides higher accuracy on complex reasoning tasks than standard LLMs while maintaining clean output formatting, though at higher latency and token cost than models without extended thinking capabilities

via “long-context reasoning with extended thinking”

Claude Opus 4.5 is Anthropic’s frontier reasoning model optimized for complex software engineering, agentic workflows, and long-horizon computer use. It offers strong multimodal capabilities, competitive performance across real-world coding and...

Unique: Implements internal chain-of-thought reasoning within a 200K token window using transformer attention mechanisms, allowing reasoning to occur before output generation without requiring explicit prompt engineering for step-by-step thinking

vs others: Outperforms GPT-4o and Claude 3.5 Sonnet on complex reasoning tasks by maintaining coherence across longer reasoning chains while keeping the 200K context window practical for real-world applications

via “extended thinking reasoning with step-by-step problem decomposition”

Gemini 2.5 Pro is Google’s state-of-the-art AI model designed for advanced reasoning, coding, mathematics, and scientific tasks. It employs “thinking” capabilities, enabling it to reason through responses with enhanced accuracy...

Unique: Implements native extended thinking as a first-class capability integrated into the model architecture, allowing transparent reasoning-before-response without requiring prompt engineering or external chain-of-thought frameworks. The thinking process is computationally budgeted and automatically triggered based on query complexity.

vs others: Provides reasoning capabilities comparable to o1 but with broader multimodal support (image/audio inputs) and lower per-token cost than specialized reasoning models, though with less user control over reasoning depth.

via “extended-reasoning-chain-of-thought-generation”

o3 is a well-rounded and powerful model across domains. It sets a new standard for math, science, coding, and visual reasoning tasks. It also excels at technical writing and instruction-following....

Unique: Implements internal extended thinking with computational budget allocation — the model allocates more inference compute to reasoning phases before answer generation, unlike standard LLMs that generate reasoning and answers in a single forward pass. This is achieved through a two-phase architecture where reasoning tokens are generated in a hidden reasoning phase before final output.

vs others: Outperforms GPT-4 and Claude 3.5 on math olympiad problems and complex reasoning tasks by 15-40% due to extended thinking budget, but at significantly higher latency and cost than standard models

via “reasoning and chain-of-thought decomposition”

The Qwen3.5 27B native vision-language Dense model incorporates a linear attention mechanism, delivering fast response times while balancing inference speed and performance. Its overall capabilities are comparable to those of...

Unique: Linear attention enables efficient reasoning over long chains of thought without quadratic slowdown — can maintain coherent reasoning across 50+ intermediate steps, whereas quadratic attention models degrade significantly with reasoning depth

vs others: More efficient reasoning than Llama 3.2 for long chains of thought due to linear attention, but less capable than Claude 3.5 Sonnet or GPT-4 for highly complex multi-domain reasoning due to smaller parameter count

via “extended-chain-of-thought reasoning with explicit thinking tokens”

Qwen3-Max-Thinking is the flagship reasoning model in the Qwen3 series, designed for high-stakes cognitive tasks that require deep, multi-step reasoning. By significantly scaling model capacity and reinforcement learning compute, it...

Unique: Uses dedicated thinking token architecture with RL-optimized allocation strategy, allowing the model to dynamically determine reasoning depth per query rather than applying fixed reasoning budgets like some competitors. Separates internal deliberation from output generation at the token level, enabling transparent reasoning traces.

vs others: Provides deeper, more transparent reasoning than standard LLMs while maintaining faster inference than some reasoning-specialized models by using learned heuristics to allocate thinking compute only when needed.

via “extended reasoning with chain-of-thought for complex visual tasks”

Qwen3-VL-30B-A3B-Thinking is a multimodal model that unifies strong text generation with visual understanding for images and videos. Its Thinking variant enhances reasoning in STEM, math, and complex tasks. It excels...

Unique: Integrates extended reasoning directly into the model's forward pass for visual tasks, rather than using post-hoc prompting techniques like 'think step-by-step', enabling the model to allocate compute dynamically to reasoning-heavy visual problems

vs others: More reliable than prompt-based chain-of-thought for visual reasoning because reasoning is baked into model weights, not dependent on prompt engineering; produces more consistent intermediate steps for STEM tasks