For models that support it, the OneRouter API can return Reasoning Tokens, also known as thinking tokens. OneRouter normalizes the different ways of customizing the amount of reasoning tokens that the model will use, providing a unified interface across different providers.
Reasoning tokens provide a transparent look into the reasoning steps taken by a model. Reasoning tokens are considered output tokens and charged accordingly.
Reasoning tokens are included in the response by default if the model decides to output them. Reasoning tokens will appear in the reasoning field of each message.
Controlling Reasoning Tokens in OpenAI Chat Completions
You can control reasoning tokens in your requests using the reasoning parameter:
{"model":"your-model","messages": [],"reasoning": {// One of the following (not both):"effort":"high",// Can be "xhigh", "high", "medium", "low", "minimal" or "none""max_tokens":2000,// Specific token limit }}
The reasoning config object consolidates settings for controlling reasoning strength across different models.
The effort can be one of below list:
"effort": "xhigh" - Allocates the largest portion of tokens for reasoning (approximately 95% of max_tokens)
"effort": "high" - Allocates a large portion of tokens for reasoning (approximately 80% of max_tokens)
"effort": "medium" - Allocates a moderate portion of tokens (approximately 50% of max_tokens)
"effort": "low" - Allocates a smaller portion of tokens (approximately 20% of max_tokens)
"effort": "minimal" - Allocates an even smaller portion of tokens (approximately 10% of max_tokens)
"effort": "none" - Disables reasoning entirely
For models that only support reasoning.max_tokens, the effort level will be set based on the percentages above.
Examples
Basic Usage with Reasoning Tokens
Using Max Tokens for Reasoning
You can specify the exact number of tokens to use for reasoning:
Streaming mode with reasoning tokens
Responses API Shape
When reasoning models generate responses, the reasoning information is structured in a standardized format through the reasoning_content item.
from openai import OpenAI
client = OpenAI(
base_url="https://llm.onerouter.pro/v1",
api_key="<<API_KEY_REF>>",
)
response = client.chat.completions.create(
model="<<MODEL>>",
messages=[
{"role": "user", "content": "How would you build the world's tallest skyscraper?"}
],
extra_body={
"reasoning": {
"effort": "high",
"max_tokens": 2000
}
},
)
print(response.model_dump_json())
from openai import OpenAI
client = OpenAI(
base_url="https://llm.onerouter.pro/v1",
api_key="<<API_KEY_REF>>",
)
response = client.chat.completions.create(
model="<<MODEL>>",
messages=[
{"role": "user", "content": "How would you build the world's tallest skyscraper?"}
],
extra_body={
"reasoning": {
"max_tokens": 200
}
},
)
print(response.model_dump_json())
from openai import OpenAI
client = OpenAI(
base_url="https://llm.onerouter.pro/v1",
api_key="<<API_KEY_REF>>",
)
def chat_completion_with_reasoning(messages):
response = client.chat.completions.create(
model="<<MODEL>>",
messages=messages,
max_tokens=10000,
extra_body={
"reasoning": {
"max_tokens": 8000,
"effort": "high"
}
},
stream=True
)
return response
for chunk in chat_completion_with_reasoning([
{"role": "user", "content": "What's bigger, 9.9 or 9.11?"}
]):
if hasattr(chunk.choices[0].delta, 'reasoning_details') and chunk.choices[0].delta.reasoning_details:
print(f"REASONING_DETAILS: {chunk.choices[0].delta.reasoning_details}")
elif getattr(chunk.choices[0].delta, 'content', None):
print(f"CONTENT: {chunk.choices[0].delta.content}")
{
"id": "chatcmpl-20251213055928959379058WiAGDQfk",
"choices": [
{
"finish_reason": "stop",
"index": 0,
"logprobs": null,
"message": {
"content": "Building the world's tallest skyscraper is less an act of construction and more an exercise in extreme, multidisciplinary problem-solving. It requires pushing the boundaries of material science, structural engineering, logistical planning, and financial investment.\n\nTo build a structure exceeding 1,000 meters (1 kilometer), the process must be segmented into critical phases, each addressing unique challenges posed by extreme height.\n\n---\n\n## Phase 1: Concept, Planning, and Site Selection\n\nThe success of a gigatall project (over 600m) is determined long before the first shovel hits the ground.\n\n### 1. Strategic Location Analysis\nLocation is paramount, as it dictates the structural loads the building must withstand.\n* **Geotechnical Stability:** The site must have strong, reliable bedrock or dense subsoil capable of bearing immense weight. Areas prone to liquefaction or shifting sands are non-starters.\n* **Seismic Risk:** Highly active earthquake zones require significantly more expensive and complex structural reinforcement, potentially making record height unfeasible.\n* **Wind Climate:** Coastal areas or flat, open plains experience harsher wind loads. The location's specific wind patterns (speed, direction, vortex frequency) must be modeled over decades.\n\n### 2. Architectural Design for Aerodynamics\nAt extreme heights, wind resistance is a far greater structural challenge than gravity. The design must actively mitigate lateral (side-to-side) forces.\n* **Tapering and Setbacks:** The building should narrow or step back as it ascends (like the Burj Khalifa). This \"confuses\" the wind, preventing a single vortex from forming along the entire height and causing excessive oscillation.\n* **Porosity:** Incorporating large openings or allowing air to pass through sections of the tower can reduce the pressure buildup on the façade.\n* **Optimal Orientation:** Modeling is used to determine the exact orientation of the building relative to prevailing winds to minimize drag.\n\n### 3. Budget and Team Assembly\nA gigatall project typically costs tens of billions of dollars. Securing political will, massive state or sovereign funding, and assembling a global team of specialized engineers (often involving firms like Skidmore, Owings & Merrill or Adrian Smith + Gordon Gill Architecture) is the initial step.\n\n---\n\n## Phase 2: Geotechnical and Foundation Engineering\n\nA record-tall building must transfer loads of hundreds of thousands of tons safely to the earth.\n\n### 1. Site Investigation\nYears of intensive geotechnical drilling and testing are required to understand the soil profile, bedrock depth, and water table.\n\n### 2. The Foundation System\nThe most common solution for extreme height involves two main components:\n* **Deep Piling:** Large-diameter reinforced concrete piles (often 1.5 to 2 meters wide) are driven or drilled deep into the stable substrate or bedrock. A structure of 1km might require hundreds of such piles, extending over 60–120 meters deep.\n* **Mat (Raft) Foundation:** A massive, thick concrete slab—sometimes several meters thick—is poured directly over the top of the piles. This mat acts as a giant \"foot\" to distribute the weight evenly across the entire pile group, minimizing differential settlement.\n\n### 3. Super-Strength Concrete\nThe foundation requires some of the strongest concrete ever mixed (Ultra-High-Performance Concrete, or UHPC). High-density, high-compressive-strength concrete (often over 80 MPa) is used in the foundation and lower core, as it must bear the full cumulative weight of the structure above.\n\n---\n\n## Phase 3: Structural System (The Skeleton)\n\nThe structural concept must be incredibly stiff, stable, and lightweight at the top.\n\n### 1. The Core System: Bundled Tube or Outrigger\nThe most viable structural system for extreme height is based on the **bundled tube concept** or the **outrigger system**, designed to maximize lateral stiffness:\n* **Central Core:** A massive, reinforced concrete central core houses the elevators and mechanical shafts. This core resists torsion (twisting).\n* **Perimeter Columns/Wings:** Structural \"wings\" or columns radiate out from the core. These are connected by horizontal steel trusses (outriggers) at specific mechanical floors.\n* **Function:** When wind pushes the building, the outriggers engage the perimeter columns, essentially using the entire building's mass to resist the force, like a giant, rigid truss structure.\n\n### 2. Material Strategy\nEngineers optimize materials based on their height and load requirements:\n* **Lower Floors:** Extremely high-strength concrete is used up to perhaps 500 meters, where gravity loads are highest.\n* **Upper Floors (The Spire):** As the gravity load decreases, structural steel is favored. Steel is lighter than concrete, reducing overall weight and allowing faster erection at the top.\n\n### 3. Dampening Systems\nEven with aerodynamic shaping, a kilometer-high building will sway. To ensure occupant comfort and structural integrity, sophisticated dampening systems are essential:\n* **Tuned Mass Dampers (TMD):** Giant pendulum weights or hydraulic pistons installed at the highest occupied floors. These systems move in opposition to the building's sway, counteracting vibration caused by wind or minor seismic events.\n\n---\n\n## Phase 4: Construction, Logistics, and Vertical Transportation\n\nMoving people and materials thousands of feet high, safely and efficiently, is often the greatest logistical challenge.\n\n### 1. Self-Climbing Systems\nConventional cranes and scaffolding are inadequate. Specialized systems are required:\n* **Self-Climbing Formwork:** The central concrete core is built using a hydraulic system that \"climbs\" the structure as the concrete cures. This speeds up construction and minimizes reliance on external cranes.\n* **Super Cranes:** Extremely powerful, temporary tower cranes are custom-engineered to climb alongside the building. They lift materials like steel beams and façade panels up to the highest working floors. Once construction is complete, these cranes must be disassembled and lowered in pieces using smaller cranes in a complex sequence (the \"crane eating crane\" method).\n\n### 2. Vertical Transportation Logistics\nWorkers, concrete, and steel must reach the top floors quickly.\n* **Construction Hoists:** High-speed temporary hoists, often external to the main structure, are dedicated solely to moving personnel and materials. These can move at speeds up to 20 meters per second.\n* **Concrete Delivery:** Pumping concrete a kilometer high requires multiple stages of high-pressure pumps located at ground level and sometimes supplemented by powerful booster pumps located at intermediate \"sky lobbies.\"\n\n---\n\n## Phase 5: Façade, Systems, and Functionality\n\nThe final phase involves enclosing the structure and installing the complex mechanical systems.\n\n### 1. Curtain Wall and Cladding\nThe façade must be lightweight, capable of handling intense pressure differentials, and highly energy efficient.\n* **Pressure Management:** As altitude increases, atmospheric pressure drops. The building enclosure must be sealed to maintain a standard internal pressure, while the outer cladding must be reinforced to handle the extreme positive and negative wind pressures.\n* **Insulation:** Specialized, high-performance glass panels are used to manage solar gain, as temperatures near the top can be significantly cooler and sun exposure more intense.\n\n### 2. HVAC and Pressure Equalization\nStandard heating and cooling systems cannot operate effectively across 1km of altitude.\n* **Zonal Systems:** The building is divided into multiple HVAC zones, typically separated at mechanical floors. This prevents the stack effect (the movement of air and smoke due to pressure differences) from overwhelming the system.\n* **Air Intake:** Air intakes for the upper zones may be located hundreds of meters above ground to draw cleaner air.\n\n### 3. Elevators and Sky Lobbies\nA conventional elevator rope cannot reach 1,000 meters. The solution involves:\n* **Sky Lobbies:** Express \"shuttle\" elevators run non-stop from the ground floor to intermediate sky lobbies (e.g., at floors 50, 100, and 150).\n* **Local Elevators:** Shorter, conventional elevators operate from the sky lobbies to serve the floors immediately above and below them.\n* **Innovation:** Future gigatall towers may utilize technologies like ropeless (magnetic levitation) elevators or high-strength carbon fiber ropes to allow for longer continuous runs.",
"refusal": null,
"role": "assistant",
"annotations": null,
"audio": null,
"function_call": null,
"tool_calls": null,
"reasoning_content": "**Thinking Through Building the World's Tallest Skyscraper**\n\nOkay, so the prompt is \"How would you build the world's tallest skyscraper?\" My immediate thought is that this isn't just a construction problem; it's a monumental engineering and logistical challenge, and I need to address it from a complete lifecycle perspective. The \"tallest\" designation implies pushing boundaries, so I'll frame my answer around the existing record-holders, the Burj Khalifa and the planned Jeddah Tower. I need to show understanding of the current state-of-the-art and then what *more* we would need to do.\n\nFirst, I need to structure my thoughts logically. A skyscraper project follows a natural progression, and I'll break it down that way: Concept & Planning, Geotechnical & Foundation, Structural Engineering, Construction & Logistics, and finally, Systems & Cladding.\n\n**Phase 1: Concept & Planning** is the foundation for everything else. This is where we make the *big* decisions: location (crucial for wind and seismic concerns), budget (gonna be *billions*), and assembling the *right* team. This isn't just about height; it has to be architecturally impressive and, importantly, *functional*.\n\n**Phase 2: Geotechnical & Foundation** is all about getting the load into the ground. We're talking about immense forces here. Extensive site testing is mandatory, followed by massive pile foundations – deep, large-diameter piles – or maybe even a truly substantial reinforced concrete raft, a mat foundation. We're dealing with \"geotechnical\" and \"load bearing\" properties here.\n\n**Phase 3: Structural Engineering** is where the *real* challenges lie. Resisting gravity, wind, and seismic loads at this scale is no joke. The structure's skeleton has to be ultra-efficient, and the bundled tube or outrigger system, like the Burj Khalifa uses, is the proven method for extreme heights. That means a strong central core and surrounding wings.\n\nWind is the enemy! Aerodynamic shaping is a necessity to mitigate the vortex effects at these altitudes. We're talking tapering, setbacks, even spiraling to confuse the wind. Stability means mass dampeners at the top to counteract sway and vibrations. It's about comfort and safety. Materials? Ultra-high-strength concrete for the lower floors, steel for the upper floors (lighter).\n\n**Phase 4: Construction & Logistics**. This is about speed, safety, and lifting materials thousands of feet in the air. We'll need self-climbing formwork, where the building *builds itself*, and super-cranes, likely mast-climbing hydraulic ones, that ascend with the structure. Vertical transportation is another major hurdle – temporary express elevators/hoists. We need a *just-in-time* supply chain.\n\n**Phase 5: Systems & Cladding**. Standard elevators just won't cut it. We need multi-deck, express shuttles, and potentially sky lobbies to break up the long vertical journeys. Maybe even something like the ropeless elevators, like ThyssenKrupp's MULTI concept. Pumping water 1 km requires relay stations. HVAC needs pressure equalization and highly efficient, multi-zone systems because air pressure changes are drastic. Cladding has to be light, durable, and super insulated, especially at high altitudes.\n\nFinally, I'll need to emphasize that it all boils down to innovation, massive financial resources, and political will. The last spire on the structure may just be symbolic but critical to being the \"tallest\". It's the ultimate height differentiator. Did I cover all the bases? Yes. Authoritative, engineering-focused – check!\n"
}
}
],
"created": 1765605586,
"model": "gemini-2.5-flash-preview-09-2025",
"object": "chat.completion",
"service_tier": null,
"system_fingerprint": null,
"usage": {
"completion_tokens": 2734,
"prompt_tokens": 12,
"total_tokens": 2746,
"completion_tokens_details": {
"accepted_prediction_tokens": null,
"audio_tokens": null,
"reasoning_tokens": 960,
"rejected_prediction_tokens": null
},
"prompt_tokens_details": {
"audio_tokens": null,
"cached_tokens": null,
"text_tokens": 12
},
"input_tokens": 0,
"output_tokens": 0,
"server_tool_use": {
"web_search_requests": ""
},
"ttft": 0
},
"request_id": "ddfd035d55b34cb69e2a00cc325230a1"
}
