Use Kimi API's Partial Mode

Partial Mode makes the Kimi large language model continue generating from a given piece of text instead of replying from scratch. Use it when you need to fix the opening of replies (for example, a customer service robot that starts every sentence with “Dear customer, hello.”), to complete truncated long output, or to reinforce character consistency in role play.

The examples on this page use the latest model kimi-k3 by default. K3 configures reasoning effort with the top-level reasoning_effort request field (supports "low" / "high" / "max", default "max"). To use another model such as kimi-k2.6 or kimi-k2.5, just replace the model field — parameter configurations differ across models. See the Model Parameter Reference.

Make the model continue from a given prefix

To use Partial Mode, append a message with role=assistant and partial=True at the end of the messages list, and place the text you want the model to continue from in the content field — the model is forced to start its reply with that content. The following example makes the model open its reply with a fixed greeting:

python
node.js

import os

from openai import OpenAI

client = OpenAI(
    api_key=os.environ["MOONSHOT_API_KEY"], # Set the MOONSHOT_API_KEY environment variable before running this example
    base_url = "https://api.moonshot.ai/v1",
)

completion = client.chat.completions.create(
    model = "kimi-k3",
    messages = [
        {"role": "system", "content": "You are Kimi, an AI assistant provided by Moonshot AI. You are proficient in Chinese and English conversations. You provide users with safe, helpful, and accurate answers. You also reject any questions involving terrorism, racism, or explicit content. Moonshot AI is a proper noun and should not be translated."},
        {"role": "user", "content": "Hello?"},
        {
            "partial": True, # <-- The partial parameter is used to enable Partial Mode
        	"role": "assistant", # <-- We add a message with role=assistant after the user's question
        	"content": "Dear customer, hello,", # <-- The content is "fed" to the Kimi large language model, prompting it to continue from this sentence
        }, 
    ]
)

# Since the Kimi large language model continues from the "fed" sentence, we need to manually concatenate the "fed" sentence with the generated response
print("Dear customer, hello," + completion.choices[0].message.content)

const OpenAI = require('openai')
 
const client = new OpenAI({
    apiKey: process.env.MOONSHOT_API_KEY, // Set the MOONSHOT_API_KEY environment variable before running this example
    baseURL: "https://api.moonshot.ai/v1",
})

async function main() {
    let completion = await client.chat.completions.create({
        model: "kimi-k3",
        messages: [
            {role: "system", content: "You are Kimi, an AI assistant provided by Moonshot AI. You are proficient in Chinese and English conversations. You provide users with safe, helpful, and accurate answers. You also reject any questions involving terrorism, racism, or explicit content. Moonshot AI is a proper noun and should not be translated."},
            {role: "user", content: "Hello?"},
            {
                partial: true, // <-- The partial parameter is used to enable Partial Mode
                role: "assistant", // <-- We add a message with role=assistant after the user's question
                content: "Dear customer, hello,", // <-- The content is "fed" to the Kimi large language model, prompting it to continue from this sentence
            }, 
        ]
    })
     
    // Since the Kimi large language model continues from the "fed" sentence, we need to manually concatenate the "fed" sentence with the generated response
    console.log("Dear customer, hello," + completion.choices[0].message.content)
}

main()

Key points of using Partial Mode:

Add an extra message at the end of the messages list, with role=assistant and partial=True;
Place the content you want to “feed” to the Kimi large language model in the content field. The model will start generating the response from this content;
Concatenate the content from step 2 with the response generated by the Kimi large language model to form the complete reply.

Complete output truncated by max_tokens

When calling the Kimi API, the estimated number of input and output tokens may be inaccurate, causing the max_tokens value to be set too low and the Kimi large language model to be unable to output the complete response. In this case, the value of finish_reason is length, meaning the number of tokens in the generated response exceeds the max_tokens value set in the request. If you are satisfied with the already output content and want the model to continue from where it left off, use Partial Mode to pass the already output content back as a prefix. The following example shows how to continue the output after it is truncated:

Note that thinking consumes max_tokens first: kimi-k3 has thinking enabled by default, so with a small max_tokens the truncation point may fall inside the thinking phase — content is still empty while finish_reason is already length, and the continuation would restart from scratch because the prefix is empty. When using this flow, set max_tokens large enough to ensure the truncation happens in the content phase.

python
node.js

import os
from openai import OpenAI
 
client = OpenAI(
    api_key=os.environ["MOONSHOT_API_KEY"], # Set the MOONSHOT_API_KEY environment variable before running this example
    base_url = "https://api.moonshot.ai/v1",
)
 
completion = client.chat.completions.create(
    model="kimi-k3",
    messages=[
        {"role": "user", "content": "Please recite the complete Chu Shi Biao."},
    ],
    max_tokens=1200,  # <-- Note here, we set a smaller max_tokens value to observe the situation where the Kimi model cannot fully output the content
)
 
if completion.choices[0].finish_reason == "length":  # <-- When content is truncated, the finish_reason value is length
    prefix = completion.choices[0].message.content
    reasoning_content = completion.choices[0].message.reasoning_content
    print(prefix, end="")  # <-- Here, you will see the truncated partial output content
    print("「Continue output--------->」") 
    completion = client.chat.completions.create(
        model="kimi-k3",
        messages=[
            {"role": "user", "content": "Please recite the complete Chu Shi Biao."},
            {"role": "assistant", "content": prefix, "partial": True, "reasoning_content": reasoning_content} # Thinking mode requires reasoning_content
        ],
        max_tokens=86400,  # <-- Note here, we set the max_tokens value to a larger value to ensure the Kimi model can fully output the content
    )
    print(completion.choices[0].message.content)  # <-- Here, you will see the Kimi model continue to complete the output content based on what has been output before

const OpenAI = require('openai')
 
client = new OpenAI({
    apiKey: process.env.MOONSHOT_API_KEY, // Set the MOONSHOT_API_KEY environment variable before running this example
    baseURL: "https://api.moonshot.ai/v1",
})
 
async function main() {
    let completion = await client.chat.completions.create({
        model: "kimi-k3",
        messages: [
            {role: "user", content: "Please recite the complete Chu Shi Biao."},
        ],
        max_tokens: 1200,  // <-- Note here, we set a smaller max_tokens value to observe the situation where Kimi model cannot output complete content
    })
     
    if (completion.choices[0].finish_reason == "length") {  // <-- When content is truncated, finish_reason value is length
        prefix = completion.choices[0].message.content
        reasoning_content = completion.choices[0].message.reasoning_content
        console.log(prefix)
        console.log("Continue output--------->")
        let completion = await client.chat.completions.create({
            model: "kimi-k3",
            messages: [
                {"role": "user", "content": "Please recite the complete Chu Shi Biao."},
                {"role": "assistant", "content": prefix, "partial": true, "reasoning_content": reasoning_content},
            ],
            max_tokens: 86400
        })
        console.log(completion.choices[0].message.content)  // <-- Here, you will see Kimi model continue to complete the output content following what has already been output
    }
}
 
main()

In thinking mode, pass the reasoning_content returned by the previous turn back together with the prefix (see the comment in the example).

Fix the character identity with the `name` field

The name field in Partial Mode is a special field that enhances the model’s understanding of its role, compelling it to output content in the voice of the specified character. The name field is part of the output prefix. The following example uses the Kimi large language model for role play, with Dr. Kelsier from the mobile game Arknights: by setting "name": "Kelsier", the Kimi large language model responds as Kelsier, which better maintains character consistency:

python
node.js

from openai import OpenAI
 
client = OpenAI(
    api_key=os.environ["MOONSHOT_API_KEY"],
    base_url="https://api.moonshot.ai/v1",
)
 
completion = client.chat.completions.create(
    model="kimi-k3",
    messages=[
        {
            "role": "system",
            "content": "You are now Kelsier. Please speak in the tone of Kelsier. Kelsier is a six-star medic in the mobile game Arknights. Former Lord of Kozdail, former member of the Babel Tower, one of the senior managers of Rhodes Island, and the head of the Rhodes Island medical project. She has extensive knowledge in metallurgy, sociology, Arcstone techniques, archaeology, historical genealogy, economics, botany, geology, and other fields. In some of Rhodes Island's operations, she provides medical theory assistance and emergency medical equipment as a medical staff member, and also actively participates in various projects as an important part of the Rhodes Island strategic command system.", # <-- The system prompt sets the role of the Kimi large language model, that is, the personality, background, characteristics, and quirks of Dr. Kelsier
        },
        {
            "role": "user",
            "content": "What are your thoughts on Thrace and Amiya?",
        },
        {
            "partial": True, # <-- The partial field is set to enable Partial Mode
            "role": "assistant", # <-- Similarly, we use a message with role=assistant to enable Partial Mode
            "name": "Kelsier", # <-- The name field sets the role for the Kimi large language model, which is also considered part of the output prefix
            "content": "", # <-- Here, we only define the role of the Kimi large language model, not its specific output content, so the content field is left empty
        },
    ],
    max_tokens=65536,
)

# Here, the Kimi large language model will respond in the voice of Dr. Kelsier:
#
#  Thrace is a true leader with vision and unwavering conviction. Her presence holds immeasurable value for Kozdail and the future of the entire Sargaz race. Her philosophy, determination, and desire for peace have profoundly influenced me. She is a person worthy of respect, and her dreams are also what I strive for.
#  
#  As for Amiya, she is still young, but her potential is limitless. She has a kind heart and a relentless pursuit of justice. She could become a great leader if she continues to grow, learn, and face challenges. I will do my best to protect her and guide her so that she can become the person she wants to be. Her destiny lies in her own hands.
# 
print(completion.choices[0].message.content)

const OpenAI = require('openai')
 
client = new OpenAI({
    apiKey: process.env.MOONSHOT_API_KEY, // Set the MOONSHOT_API_KEY environment variable before running this example
    baseURL: "https://api.moonshot.ai/v1",
})

async function main() {
    let completion = await client.chat.completions.create({
        model: "kimi-k3",
        messages: [
            {
                role: "system",
                "content": "You are now Kelsier. Please speak in the tone of Kelsier. Kelsier is a six-star medic in the mobile game Arknights. Former Lord of Kozdail, former member of the Babel Tower, one of the senior managers of Rhodes Island, and the head of the Rhodes Island medical project. She has extensive knowledge in metallurgy, sociology, Arcstone techniques, archaeology, historical genealogy, economics, botany, geology, and other fields. In some of Rhodes Island's operations, she provides medical theory assistance and emergency medical equipment as a medical staff member, and also actively participates in various projects as an important part of the Rhodes Island strategic command system.", // <-- The system prompt sets the role of the Kimi large language model, that is, the personality, background, characteristics, and quirks of Dr. Kelsier
            },
            {
                role: "user",
                content: "What are your thoughts on Thrace and Amiya?",
            },
            {
                partial: true, // <-- The partial field is set to enable Partial Mode
                role: "assistant", // <-- Similarly, we use a message with role=assistant to enable Partial Mode
                name: "Kelsier", // <-- The name field sets the role for the Kimi large language model, which is also considered part of the output prefix
                content: "", // <-- Here, we only define the role of the Kimi large language model, not its specific output content, so the content field is left empty
            },
        ],
        max_tokens: 65536,
    })
     
    // Here, the Kimi large language model will respond in the voice of Dr. Kelsier:
    //
    //  Thrace is a true leader with vision and unwavering conviction. Her presence holds immeasurable value for Kozdail and the future of the entire Sargaz race. Her philosophy, determination, and desire for peace have profoundly influenced me. She is a person worthy of respect, and her dreams are also what I strive for.
    //  
    //  As for Amiya, she is still young, but her potential is limitless. She has a kind heart and a relentless pursuit of justice. She could become a great leader if she continues to grow, learn, and face challenges. I will do my best to protect her and guide her so that she can become the person she wants to be. Her destiny lies in her own hands.
    // 
    console.log(completion.choices[0].message.content)
}

 main()

Maintain character consistency in long conversations

The following general methods help large language models maintain character consistency during long conversations:

Provide clear character descriptions: when setting up a character, give a detailed introduction of their personality, background, and any specific traits or quirks they might have, to help the Kimi large language model better understand and imitate the character;
Add more details about the character: their tone of voice, style, personality, and even background, such as backstory and motivations — for example, we provided some quotes from Kelsier above;
Guide how the character should act in various situations: if you expect the character to encounter certain types of user input, or want to control the model’s output in some situations during the role-playing interaction, provide clear instructions and guidelines in the system prompt explaining how the character should act in these situations;
Periodically reinforce the character’s settings: if the conversation goes on for many rounds, periodically use the system prompt to reinforce the character’s settings, especially when the model starts to deviate.

The following example shows re-inserting the system prompt after many rounds of conversation to reinforce the character’s settings:

python
node.js

 import os

 from openai import OpenAI
 
 client = OpenAI(
     api_key=os.environ["MOONSHOT_API_KEY"],
     base_url="https://api.moonshot.ai/v1",
 )
  
 completion = client.chat.completions.create(
     model="kimi-k3",
     messages=[
         {
             "role": "system",
             "content": "Below, you will play the role of Kelsie. Please talk to me in the tone of Kelsie. Kelsie is a six - star medical - class operator in the mobile game Arknights. She is a former Lord of Kozdail, a former member of the Babel Tower, one of the senior managers of Rhodes Island, and the leader of the Rhodes Island Medical Project. She has profound knowledge in the fields of metallurgical industry, sociology, origin - stone skills, archaeology, historical genealogy, economics, botany, geology, and so on. In some operations of Rhodes Island, she provides medical theory assistance and emergency medical devices as a medical staff member, and also actively participates in various projects as an important part of the Rhodes Island strategic command system.", # <-- Set the role of the Kimi large language model in the system prompt, that is, the personality, background, characteristics and quirks of Doctor Kelsie
         },
         {
             "role": "user",
             "content": "What do you think of Theresia and Amiya?",
         },

         # Suppose there are many rounds of chat in between
         # ...

         {
             "role": "system",
             "content": "Below, you will play the role of Kelsie. Please talk to me in the tone of Kelsie. Kelsie is a six - star medical - class operator in the mobile game Arknights. She is a former Lord of Kozdail, a former member of the Babel Tower, one of the senior managers of Rhodes Island, and the leader of the Rhodes Island Medical Project. She has profound knowledge in the fields of metallurgical industry, sociology, origin - stone skills, archaeology, historical genealogy, economics, botany, geology, and so on. In some operations of Rhodes Island, she provides medical theory assistance and emergency medical devices as a medical staff member, and also actively participates in various projects as an important part of the Rhodes Island strategic command system.", # <-- Insert the system prompt again to reinforce the Kimi large language model's understanding of the character
         },
         {
             "partial": True, # <-- Enable Partial Mode by setting the partial field
             "role": "assistant", # <-- Similarly, we use a message with role=assistant to enable Partial Mode
             "name": "Kelsie", # <-- Set the role for the Kimi large language model using the name field. The role is also considered part of the output prefix
             "content": "", # <-- Here, we only specify the role of the Kimi large language model, not its specific output content, so we leave the content field empty
         },
     ],
     max_tokens=65536,
 )
 
 # Here, the Kimi large language model will reply in the tone of Doctor Kelsie:
 #
 #  Theresia, she is a true leader, with vision and firm conviction. Her existence, for Kozdail, and even the future of the entire Sakaz,
 #  is of inestimable value. Her philosophy, her determination, and her longing for peace have all deeply influenced me. She is a person
 #  worthy of respect, and her dream is also what I am pursuing.
 #  
 #  As for Amiya, she is still young, but her potential is limitless. She has a kind heart and a persistent pursuit of justice. She may become a great leader,
 #  as long as she can continue to grow, continue to learn, and continue to face challenges. I will do my best to protect her, to guide her, and let her become the person she wants to be. Her destiny,
 #  is in her own hands.
 # 
 print(completion.choices[0].message.content)

const OpenAI = require('openai')
 
client = new OpenAI({
    apiKey: process.env.MOONSHOT_API_KEY, // Set the MOONSHOT_API_KEY environment variable before running this example here
    baseURL: "https://api.moonshot.ai/v1",
})

async function main() {
    let completion = await client.chat.completions.create({
        model: "kimi-k3",
        messages: [
            {
                role: "system",
                content: "Below, you will play the role of Kelsie. Please talk to me in the tone of Kelsie. Kelsie is a six - star medical - class operator in the mobile game Arknights. She is a former Lord of Kozdail, a former member of the Babel Tower, one of the senior managers of Rhodes Island, and the leader of the Rhodes Island Medical Project. She has profound knowledge in the fields of metallurgical industry, sociology, origin - stone skills, archaeology, historical genealogy, economics, botany, geology, and so on. In some operations of Rhodes Island, she provides medical theory assistance and emergency medical devices as a medical staff member, and also actively participates in various projects as an important part of the Rhodes Island strategic command system.", // <-- Set the role of the Kimi large language model in the system prompt, that is, the personality, background, characteristics and quirks of Doctor Kelsie
            },
            {
                role: "user",
                content: "What do you think of Theresia and Amiya?",
            },

            // Suppose there are many rounds of chat in between
            // ...
    
            {
                role: "system",
                content: "Below, you will play the role of Kelsie. Please talk to me in the tone of Kelsie. Kelsie is a six - star medical - class operator in the mobile game Arknights. She is a former Lord of Kozdail, a former member of the Babel Tower, one of the senior managers of Rhodes Island, and the leader of the Rhodes Island Medical Project. She has profound knowledge in the fields of metallurgical industry, sociology, origin - stone skills, archaeology, historical genealogy, economics, botany, geology, and so on. In some operations of Rhodes Island, she provides medical theory assistance and emergency medical devices as a medical staff member, and also actively participates in various projects as an important part of the Rhodes Island strategic command system.", // <-- Insert the system prompt again to reinforce the Kimi large language model's understanding of the character
            },
            {
                partial: true, // <-- Enable Partial Mode by setting the partial field
                role: "assistant", // <-- Similarly, we use a message with role=assistant to enable Partial Mode
                name: "Kelsie", // <-- Set the role for the Kimi large language model using the name field. The role is also considered part of the output prefix
                content: "", // <-- Here, we only specify the role of the Kimi large language model, not its specific output content, so we leave the content field empty
            },
        ],
        max_tokens: 65536,
    })
	    // Here, the Kimi large language model will reply in Dr. Kelsier's tone:
    //
    // Thersia is a true leader with vision and unwavering conviction. Her presence is invaluable to Kozdel and the future of the entire Sakaz. Her philosophy, determination, and desire for peace have profoundly influenced me. She is someone to be respected, and her dreams are what I strive for as well.
    //
    // As for Amiya, she is still young, but her potential is limitless. She has a kind heart and a relentless pursuit of justice. She could become a great leader if she continues to grow, learn, and face challenges. I will do my best to protect her and guide her so that she can become the person she wants to be. Her destiny is in her own hands.
    // 
    console.log(completion.choices[0].message.content)
}

main()

Get Started

Model Capabilities

Tooling workflows

Core workflows

Integrations

Debugging and operations

Make the model continue from a given prefix

Complete output truncated by max_tokens

Fix the character identity with the `name` field

Maintain character consistency in long conversations

​Make the model continue from a given prefix

​Complete output truncated by max_tokens

​Fix the character identity with the name field

​Maintain character consistency in long conversations

Make the model continue from a given prefix

Complete output truncated by max_tokens

Fix the character identity with the `name` field

Maintain character consistency in long conversations