Thinking Mode

Thinking/Reasoning models represent a new generation of LLMs specifically trained to expose their internal reasoning process. Unlike traditional LLMs that only show final outputs, thinking models like Claude 3.7 Sonnet, OpenAI o1/o3, and Deepseek R1 are designed to “think out loud” - producing a detailed chain of thought before delivering their final response.

These reasoning-optimized models are built to excel in tasks requiring complex analysis, multi-step problem solving, and structured logical thinking. Portkey makes these advanced models accessible through a unified API specification that works consistently across providers.

Supported Thinking Models

Portkey currently supports the following thinking-enabled models:

• Anthropic: claude-3-7-sonnet-latest
• Google Vertex AI: anthropic.claude-3-7-sonnet@20250219
• Amazon Bedrock: claude-3-7-sonnet

More thinking models will be supported as they become available.

Using Thinking Mode

1. You must set strict_open_ai_compliance=False in your headers or client configuration
2. The thinking response is returned in a different format than standard completions
3. For streaming responses, the thinking content is in response_chunk.choices[0].delta.content_blocks

Extended thinking API through Portkey is currently in beta.

Basic Example

Python

from portkey_ai import Portkey

# Initialize the Portkey client
portkey = Portkey(
    api_key="PORTKEY_API_KEY",  # Replace with your Portkey API key
    virtual_key="VIRTUAL_KEY",   # Add your provider's virtual key
    strict_open_ai_compliance=False  # Required for thinking mode
)

# Create the request
response = portkey.chat.completions.create(
  model="claude-3-7-sonnet-latest",
  max_tokens=3000,
  thinking={
      "type": "enabled",
      "budget_tokens": 2030  # Maximum tokens to use for thinking
  },
  stream=False,
  messages=[
      {
          "role": "user",
          "content": [
              {
                  "type": "text",
                  "text": "when does the flight from new york to bengaluru land tomorrow, what time, what is its flight number, and what is its baggage belt?"
              }
          ]
      }
  ]
)
print(response)

# For streaming responses, handle content_blocks differently
# response = portkey.chat.completions.create(
#   ...same config as above but with stream=True
# )
# for chunk in response:
#     if chunk.choices[0].delta:
#         content_blocks = chunk.choices[0].delta.get("content_blocks")
#         if content_blocks is not None:
#             for content_block in content_blocks:
#                 print(content_block)

Node.js

import Portkey from 'portkey-ai';

// Initialize the Portkey client
const portkey = new Portkey({
  apiKey: "PORTKEY_API_KEY", // Replace with your Portkey API key
  virtualKey: "VIRTUAL_KEY", // Add your provider's virtual key
  strictOpenAiCompliance: false // Required for thinking mode
});

// Generate a chat completion
async function getChatCompletionWithThinking() {
    const response = await portkey.chat.completions.create({
      model: "claude-3-7-sonnet-latest",
      max_tokens: 3000,
      thinking: {
          type: "enabled",
          budget_tokens: 2030
      },
      stream: false,
      messages: [
          {
              role: "user",
              content: [
                  {
                      type: "text",
                      text: "when does the flight from new york to bengaluru land tomorrow, what time, what is its flight number, and what is its baggage belt?"
                  }
              ]
          }
      ]
    });
    console.log(response);

  // For streaming responses:
  // const response = await portkey.chat.completions.create({
  //   ...same config as above but with stream: true
  // });
  // for await (const chunk of response) {
  //   if (chunk.choices[0].delta?.content_blocks) {
  //     for (const contentBlock of chunk.choices[0].delta.content_blocks) {
  //       console.log(contentBlock);
  //     }
  //   }
  // }
  }

// Call the function
getChatCompletionWithThinking();

OpenAI SDK (JS)

import OpenAI from 'openai'; // We're using the v4 SDK
import { PORTKEY_GATEWAY_URL, createHeaders } from 'portkey-ai'

const openai = new OpenAI({
  apiKey: 'ANTHROPIC_API_KEY', // defaults to process.env["OPENAI_API_KEY"],
  baseURL: PORTKEY_GATEWAY_URL,
  defaultHeaders: createHeaders({
    provider: "anthropic",
    apiKey: "PORTKEY_API_KEY", // defaults to process.env["PORTKEY_API_KEY"]
    strictOpenAiCompliance: false
  })
});

// Generate a chat completion with thinking mode
async function getChatCompletionFunctions(){
  const response = await openai.chat.completions.create({
    model: "claude-3-7-sonnet-latest",
    max_tokens: 3000,
    thinking: {
        type: "enabled",
        budget_tokens: 2030
    },
    stream: false,
    messages: [
        {
            role: "user",
            content: [
                {
                    type: "text",
                    text: "when does the flight from new york to bengaluru land tomorrow, what time, what is its flight number, and what is its baggage belt?"
                }
            ]
        }
    ],
  });

  console.log(response)
}
await getChatCompletionFunctions();

OpenAI SDK (Python)

from openai import OpenAI
from portkey_ai import PORTKEY_GATEWAY_URL, createHeaders

openai = OpenAI(
    api_key='ANTHROPIC_API_KEY',
    base_url=PORTKEY_GATEWAY_URL,
    default_headers=createHeaders(
        provider="anthropic",
        api_key="PORTKEY_API_KEY",
        strict_open_ai_compliance=False
    )
)

response = openai.chat.completions.create(
    model="claude-3-7-sonnet-latest",
    max_tokens=3000,
    thinking={
        "type": "enabled",
        "budget_tokens": 2030
    },
    stream=False,
    messages=[
        {
            "role": "user",
            "content": [
                {
                    "type": "text",
                    "text": "when does the flight from new york to bengaluru land tomorrow, what time, what is its flight number, and what is its baggage belt?"
                }
            ]
        }
    ]
)

print(response)

cURL

curl "https://api.portkey.ai/v1/chat/completions" \
  -H "Content-Type: application/json" \
  -H "x-portkey-api-key: $PORTKEY_API_KEY" \
  -H "x-portkey-provider: anthropic" \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "x-portkey-strict-open-ai-compliance: false" \
  -d '{
    "model": "claude-3-7-sonnet-latest",
    "max_tokens": 3000,
    "thinking": {
      "type": "enabled",
      "budget_tokens": 2030
    },
    "stream": false,
    "messages": [
      {
        "role": "user",
        "content": [
          {
            "type": "text",
            "text": "when does the flight from new york to bengaluru land tomorrow, what time, what is its flight number, and what is its baggage belt?"
          }
        ]
      }
    ]
  }'

Multi-Turn Conversations

For multi-turn conversations, include the previous thinking content in the conversation history:

Python

from portkey_ai import Portkey

# Initialize the Portkey client
portkey = Portkey(
    api_key="PORTKEY_API_KEY",  # Replace with your Portkey API key
    virtual_key="VIRTUAL_KEY",   # Add your provider's virtual key
    strict_open_ai_compliance=False
)

# Create the request
response = portkey.chat.completions.create(
  model="claude-3-7-sonnet-latest",
  max_tokens=3000,
  thinking={
      "type": "enabled",
      "budget_tokens": 2030
  },
  stream=False,
  messages=[
      {
          "role": "user",
          "content": [
              {
                  "type": "text",
                  "text": "when does the flight from baroda to bangalore land tomorrow, what time, what is its flight number, and what is its baggage belt?"
              }
          ]
      },
      {
          "role": "assistant",
          "content": [
                  {
                      "type": "thinking",
                      "thinking": "The user is asking several questions about a flight from Baroda (also known as Vadodara) to Bangalore:\n1. When does the flight land tomorrow\n2. What time does it land\n3. What is the flight number\n4. What is the baggage belt number at the arrival airport\n\nTo properly answer these questions, I would need access to airline flight schedules and airport information systems. However, I don't have:\n- Real-time or scheduled flight information\n- Access to airport baggage claim allocation systems\n- Information about specific flights between these cities\n- The ability to look up tomorrow's specific flight schedules\n\nThis question requires current, specific flight information that I don't have access to. Instead of guessing or providing potentially incorrect information, I should explain this limitation and suggest ways the user could find this information.",
                      "signature": "EqoBCkgIARABGAIiQBVA7FBNLRtWarDSy9TAjwtOpcTSYHJ+2GYEoaorq3V+d3eapde04bvEfykD/66xZXjJ5yyqogJ8DEkNMotspRsSDKzuUJ9FKhSNt/3PdxoMaFZuH+1z1aLF8OeQIjCrA1+T2lsErrbgrve6eDWeMvP+1sqVqv/JcIn1jOmuzrPi2tNz5M0oqkOO9txJf7QqEPPw6RG3JLO2h7nV1BMN6wE="
                  }
          ]
      },
      {
          "role": "user",
          "content": "thanks that's good to know, how about to chennai?"
      }
  ]
)
print(response)

import Portkey from 'portkey-ai';

// Initialize the Portkey client
const portkey = new Portkey({
  apiKey: "PORTKEY_API_KEY", // Replace with your Portkey API key
  virtualKey: "VIRTUAL_KEY", // Add your anthropic's virtual key
  strictOpenAiCompliance: false
});

// Generate a chat completion
async function getChatCompletionFunctions() {
    const response = await portkey.chat.completions.create({
      model: "claude-3-7-sonnet-latest",
      max_tokens: 3000,
      thinking: {
          type: "enabled",
          budget_tokens: 2030
      },
      stream: false,
      messages: [
          {
              role: "user",
              content: [
                  {
                      type: "text",
                      text: "when does the flight from baroda to bangalore land tomorrow, what time, what is its flight number, and what is its baggage belt?"
                  }
              ]
          },
          {
              role: "assistant",
              content: [
                      {
                          type: "thinking",
                          thinking: "The user is asking several questions about a flight from Baroda (also known as Vadodara) to Bangalore:\n1. When does the flight land tomorrow\n2. What time does it land\n3. What is the flight number\n4. What is the baggage belt number at the arrival airport\n\nTo properly answer these questions, I would need access to airline flight schedules and airport information systems. However, I don't have:\n- Real-time or scheduled flight information\n- Access to airport baggage claim allocation systems\n- Information about specific flights between these cities\n- The ability to look up tomorrow's specific flight schedules\n\nThis question requires current, specific flight information that I don't have access to. Instead of guessing or providing potentially incorrect information, I should explain this limitation and suggest ways the user could find this information.",
                          signature: "EqoBCkgIARABGAIiQBVA7FBNLRtWarDSy9TAjwtOpcTSYHJ+2GYEoaorq3V+d3eapde04bvEfykD/66xZXjJ5yyqogJ8DEkNMotspRsSDKzuUJ9FKhSNt/3PdxoMaFZuH+1z1aLF8OeQIjCrA1+T2lsErrbgrve6eDWeMvP+1sqVqv/JcIn1jOmuzrPi2tNz5M0oqkOO9txJf7QqEPPw6RG3JLO2h7nV1BMN6wE="
                      }
              ]
          },
          {
              role: "user",
              content: "thanks that's good to know, how about to chennai?"
          }
      ]
    });
    console.log(response);
  }
// Call the function
getChatCompletionFunctions();

import OpenAI from 'openai'; // We're using the v4 SDK
import { PORTKEY_GATEWAY_URL, createHeaders } from 'portkey-ai'

const openai = new OpenAI({
  apiKey: 'ANTHROPIC_API_KEY', // defaults to process.env["OPENAI_API_KEY"],
  baseURL: PORTKEY_GATEWAY_URL,
  defaultHeaders: createHeaders({
    provider: "anthropic",
    apiKey: "PORTKEY_API_KEY", // defaults to process.env["PORTKEY_API_KEY"]
    strict_open_ai_compliance: false
  })
});

// Generate a chat completion with streaming
async function getChatCompletionFunctions(){
  const response = await openai.chat.completions.create({
    model: "claude-3-7-sonnet-latest",
    max_tokens: 3000,
    thinking: {
        type: "enabled",
        budget_tokens: 2030
    },
    stream: false,
    messages: [
        {
            role: "user",
            content: [
                {
                    type: "text",
                    text: "when does the flight from baroda to bangalore land tomorrow, what time, what is its flight number, and what is its baggage belt?"
                }
            ]
        },
        {
            role: "assistant",
            content: [
                    {
                        type: "thinking",
                        thinking: "The user is asking several questions about a flight from Baroda (also known as Vadodara) to Bangalore:\n1. When does the flight land tomorrow\n2. What time does it land\n3. What is the flight number\n4. What is the baggage belt number at the arrival airport\n\nTo properly answer these questions, I would need access to airline flight schedules and airport information systems. However, I don't have:\n- Real-time or scheduled flight information\n- Access to airport baggage claim allocation systems\n- Information about specific flights between these cities\n- The ability to look up tomorrow's specific flight schedules\n\nThis question requires current, specific flight information that I don't have access to. Instead of guessing or providing potentially incorrect information, I should explain this limitation and suggest ways the user could find this information.",
                        signature: "EqoBCkgIARABGAIiQBVA7FBNLRtWarDSy9TAjwtOpcTSYHJ+2GYEoaorq3V+d3eapde04bvEfykD/66xZXjJ5yyqogJ8DEkNMotspRsSDKzuUJ9FKhSNt/3PdxoMaFZuH+1z1aLF8OeQIjCrA1+T2lsErrbgrve6eDWeMvP+1sqVqv/JcIn1jOmuzrPi2tNz5M0oqkOO9txJf7QqEPPw6RG3JLO2h7nV1BMN6wE="
                    }
            ]
        },
        {
            role: "user",
            content: "thanks that's good to know, how about to chennai?"
        }
    ],
  });

  console.log(response)

}
await getChatCompletionFunctions();

from openai import OpenAI
from portkey_ai import PORTKEY_GATEWAY_URL, createHeaders

openai = OpenAI(
    api_key='Anthropic_API_KEY',
    base_url=PORTKEY_GATEWAY_URL,
    default_headers=createHeaders(
        provider="anthropic",
        api_key="PORTKEY_API_KEY",
        strict_open_ai_compliance=False
    )
)


response = openai.chat.completions.create(
    model="claude-3-7-sonnet-latest",
    max_tokens=3000,
    thinking={
        "type": "enabled",
        "budget_tokens": 2030
    },
    stream=False,
    messages=[
        {
            "role": "user",
            "content": [
                {
                    "type": "text",
                    "text": "when does the flight from baroda to bangalore land tomorrow, what time, what is its flight number, and what is its baggage belt?"
                }
            ]
        },
        {
            "role": "assistant",
            "content": [
                    {
                        "type": "thinking",
                        "thinking": "The user is asking several questions about a flight from Baroda (also known as Vadodara) to Bangalore:\n1. When does the flight land tomorrow\n2. What time does it land\n3. What is the flight number\n4. What is the baggage belt number at the arrival airport\n\nTo properly answer these questions, I would need access to airline flight schedules and airport information systems. However, I don't have:\n- Real-time or scheduled flight information\n- Access to airport baggage claim allocation systems\n- Information about specific flights between these cities\n- The ability to look up tomorrow's specific flight schedules\n\nThis question requires current, specific flight information that I don't have access to. Instead of guessing or providing potentially incorrect information, I should explain this limitation and suggest ways the user could find this information.",
                        signature: "EqoBCkgIARABGAIiQBVA7FBNLRtWarDSy9TAjwtOpcTSYHJ+2GYEoaorq3V+d3eapde04bvEfykD/66xZXjJ5yyqogJ8DEkNMotspRsSDKzuUJ9FKhSNt/3PdxoMaFZuH+1z1aLF8OeQIjCrA1+T2lsErrbgrve6eDWeMvP+1sqVqv/JcIn1jOmuzrPi2tNz5M0oqkOO9txJf7QqEPPw6RG3JLO2h7nV1BMN6wE="
                    }
            ]
        },
        {
            "role": "user",
            "content": "thanks that's good to know, how about to chennai?"
        }
    ]
)

print(response)

curl "https://api.portkey.ai/v1/chat/completions" \
  -H "Content-Type: application/json" \
  -H "x-portkey-api-key: $PORTKEY_API_KEY" \
  -H "x-portkey-provider: anthropic" \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "x-portkey-strict-open-ai-compliance: false" \
  -d '{
    "model": "claude-3-7-sonnet-latest",
    "max_tokens": 3000,
    "thinking": {
      "type": "enabled",
      "budget_tokens": 2030
    },
    "stream": false,
    "messages": [
      {
        "role": "user",
        "content": [
          {
            "type": "text",
            "text": "when does the flight from baroda to bangalore land tomorrow, what time, what is its flight number, and what is its baggage belt?"
          }
        ]
      },
      {
        "role": "assistant",
        "content": [
                {
                    "type": "thinking",
                    "thinking": "The user is asking several questions about a flight from Baroda (also known as Vadodara) to Bangalore:\n1. When does the flight land tomorrow\n2. What time does it land\n3. What is the flight number\n4. What is the baggage belt number at the arrival airport\n\nTo properly answer these questions, I would need access to airline flight schedules and airport information systems. However, I don't have:\n- Real-time or scheduled flight information\n- Access to airport baggage claim allocation systems\n- Information about specific flights between these cities\n- The ability to look up tomorrow's specific flight schedules\n\nThis question requires current, specific flight information that I don't have access to. Instead of guessing or providing potentially incorrect information, I should explain this limitation and suggest ways the user could find this information.",
                    "signature": "EqoBCkgIARABGAIiQBVA7FBNLRtWarDSy9TAjwtOpcTSYHJ+2GYEoaorq3V+d3eapde04bvEfykD/66xZXjJ5yyqogJ8DEkNMotspRsSDKzuUJ9FKhSNt/3PdxoMaFZuH+1z1aLF8OeQIjCrA1+T2lsErrbgrve6eDWeMvP+1sqVqv/JcIn1jOmuzrPi2tNz5M0oqkOO9txJf7QqEPPw6RG3JLO2h7nV1BMN6wE="
                }
        ]
      },
      {
        "role": "user",
        "content": "thanks that's good to know, how about to chennai?"
      }
    ]
  }'

Understanding Response Format

When using thinking-enabled models, be aware of the special response format:

The assistant’s thinking response is returned in the response_chunk.choices[0].delta.content_blocks array, not the response.choices[0].message.content string.

This is especially important for streaming responses, where you’ll need to specifically parse and extract the thinking content from the content blocks.

When to Use Thinking Models

Thinking models are particularly valuable in specific use cases:

FAQs

Can I use thinking mode with any model?

No, thinking mode is only available on specific reasoning-optimized models. Currently, this includes Claude 3.7 Sonnet and will expand to other models as they become available.

Does thinking mode increase token usage?

Yes, enabling thinking mode will increase your token usage since the model is generating additional content for its reasoning process. The budget_tokens parameter lets you control the maximum tokens allocated to thinking.

Do I need to handle the response differently for thinking mode?

Yes, particularly for streaming responses. The thinking content is returned in the content_blocks array rather than the standard content field, so you’ll need to adapt your response parsing logic.

Why do I need to set strict_open_ai_compliance to false?

The thinking mode response format extends beyond the standard OpenAI completion schema. Setting strict_open_ai_compliance to false allows Portkey to return this extended format with the thinking content.