| 1 | # Interleaved Thinking |
| 2 | |
| 3 | ## Introduction |
| 4 | |
| 5 | Interleaved thinking allows models to reason between tool calls, enabling more sophisticated decision-making after receiving tool results. This feature helps models chain multiple tool calls with reasoning steps in between and make nuanced decisions based on intermediate results. |
| 6 | |
| 7 | Important: Interleaved thinking increases token usage and response latency. Consider your budget and performance requirements when enabling this feature. |
| 8 | |
| 9 | ## How Interleaved Thinking Works |
| 10 | |
| 11 | With interleaved thinking, the model can: |
| 12 | |
| 13 | - Reason about the results of a tool call before deciding what to do next |
| 14 | - Chain multiple tool calls with reasoning steps in between |
| 15 | - Make more nuanced decisions based on intermediate results |
| 16 | - Provide transparent reasoning for its tool selection process |
| 17 | |
| 18 | ## Supported Models |
| 19 | |
| 20 | vLLM currently supports the following interleaved thinking models: |
| 21 | |
| 22 | | Model Series | Reasoning Parser Name | |
| 23 | | ------------ | --------------------- | |
| 24 | | moonshotai/Kimi-K2-Thinking | kimi_k2 | |
| 25 | | MiniMaxAI/MiniMax-M2 | minimax_m2 | |
| 26 | |
| 27 | ## Example Usage |
| 28 | |
| 29 | To use interleaved thinking with tool calls, specify a model that supports this feature and enable tool calls in your chat completion request. Here's an example: |
| 30 | |
| 31 | ??? code |
| 32 | |
| 33 | ```python |
| 34 | """ |
| 35 | vllm serve MiniMaxAI/MiniMax-M2 \ |
| 36 | --tensor-parallel-size 4 \ |
| 37 | --tool-call-parser minimax_m2 \ |
| 38 | --reasoning-parser minimax_m2 \ |
| 39 | --enable-auto-tool-choice |
| 40 | """ |
| 41 | import json |
| 42 | |
| 43 | from openai import OpenAI |
| 44 | |
| 45 | client = OpenAI(base_url="http://localhost:8000/v1", api_key="dummy") |
| 46 | |
| 47 | |
| 48 | def get_current_weather(location: str, unit: "str"): |
| 49 | """Get the current weather in a given location""" |
| 50 | if unit == "celsius": |
| 51 | return f"The current temperature in {location} is 22°C." |
| 52 | else: |
| 53 | return f"The current temperature in {location} is 72°F." |
| 54 | |
| 55 | |
| 56 | tools = [ |
| 57 | { |
| 58 | "type": "function", |
| 59 | "function": { |
| 60 | "name": "get_weather", |
| 61 | "description": "Get the current weather in a given location", |
| 62 | "parameters": { |
| 63 | "type": "object", |
| 64 | "properties": { |
| 65 | "location": { |
| 66 | "type": "string", |
| 67 | "description": "City and state, e.g., 'San Francisco, CA'", |
| 68 | }, |
| 69 | "unit": {"type": "string", "enum": ["celsius", "fahrenheit"]}, |
| 70 | }, |
| 71 | "required": ["location", "unit"], |
| 72 | }, |
| 73 | }, |
| 74 | } |
| 75 | ] |
| 76 | messages = [{"role": "user", "content": "What's the weather in Fahrenheit like in San Francisco?"}] |
| 77 | response = client.chat.completions.create( |
| 78 | model=client.models.list().data[0].id, |
| 79 | messages=messages, |
| 80 | tools=tools, |
| 81 | tool_choice="auto", |
| 82 | ) |
| 83 | |
| 84 | tool_call = response.choices[0].message.tool_calls[0].function |
| 85 | |
| 86 | messages.append( |
| 87 | { |
| 88 | "role": "assistant", |
| 89 | "tool_calls": response.choices[0].message.tool_calls, |
| 90 | "reasoning": response.choices[0].message.reasoning, # append reasoning |
| 91 | } |
| 92 | ) |
| 93 | |
| 94 | # Simulate tool execution |
| 95 | available_tools = {"get_weather": get_current_weather} |
| 96 | |
| 97 | completion_tool_calls = response.choices[0].message.tool_calls |
| 98 | for call in completion_tool_calls: |
| 99 | tool_to_call = available_tools[call.function.name] |
| 100 | args = json.loads(call.function.arguments) |
| 101 | result = tool_to_call(**args) |
| 102 | messages.append( |
| 103 | { |
| 104 | "role": "tool", |
| 105 | "content": result, |
| 106 | "tool_call_id": call.id, |
| 107 | "name": call.function.name, |
| 108 | } |
| 109 | ) |
| 110 | response_2 = client.chat.completions.create( |
| 111 | model=client.models.list().data[0].id, |
| 112 | messages=messages, |
| 113 | tools=tools, |
| 114 | tool_choice="auto", |
| 115 | ) |
| 116 | print(response_2.choices[0].message.content) |
| 117 | ``` |
| 118 | This example demonstrates how to set up interleaved thinking with tool calls using a weather retrieval function. The model reasons about the tool results before generating the final response. |