K2.5's Thinking and Instant modes are not changed by editing a text prompt alone: the official guidance gives the two modes different temperatures and requires explicitly switching between them through the API/extra_body. Third-party deployments also need to verify the chat template, reasoning_content, and provider parser.
Suitable tasks: text/image/video conversations, visual analysis, coding agents, search, and multi-step tool calls.
Unsuitable tasks: mixing Thinking and Instant parameters, or deploying tool writes directly without verifying the provider.
Applicable model versions: Kimi K2.5; official API and vLLM/SGLang/KTransformers versions may use different fields.
Applicable clients, agents, or APIs: Kimi API, OpenAI/Anthropic-compatible APIs, Kimi Code, vLLM/SGLang.
Recommended reasoning levels and parameters: Thinking temperature=1.0, top_p=0.95; Instant temperature=0.6, top_p=0.95; context length 256k; set max_tokens according to the task.
import openai
client = openai.OpenAI(api_key="<KIMI_API_KEY>", base_url="<KIMI_BASE_URL>")
messages = [
{"role": "system", "content": "You are Kimi, an AI assistant created by Moonshot AI."},
{"role": "user", "content": "Analyze this image and list verifiable facts, anomalies, and next checks."}
]
# Thinking mode: official API
thinking = client.chat.completions.create(
model="kimi-k2.5",
messages=messages,
temperature=1.0,
top_p=0.95,
max_tokens=8192,
extra_body={"thinking": {"type": "enabled"}},
)
# Instant mode: official API
instant = client.chat.completions.create(
model="kimi-k2.5",
messages=messages,
temperature=0.6,
top_p=0.95,
max_tokens=4096,
extra_body={"thinking": {"type": "disabled"}},
)For vLLM/SGLang, the official repository says Instant can use extra_body={"chat_template_kwargs":{"thinking":False}}; run the Kimi Vendor Verifier before deployment.
Use the same input to test Thinking and Instant separately for latency, tokens, correctness, and tool calls.
For visual tasks, record the original images/videos, media encoding, dimensions, request fields, and output; do not record only the text.
Run the Vendor Verifier/KVV and multi-turn tool calls for third-party providers, and compare the output with the official API.
Check that multi-turn assistant messages correctly preserve reasoning_content; remove explicit null values to avoid contaminating the chat template.
During load testing, verify 200/429 responses, empty responses, timeouts, early EOS termination, and idempotent retries.
The official repository gives temperature=1.0 for Thinking, temperature=0.6 for Instant, and top_p=0.95, and distinguishes the switching fields for the official API and vLLM/SGLang.
Official model summary: MoE, 1T total parameters, 32B active parameters, 256K context, and native vision.
Officially recommended deployment engines include vLLM, SGLang, and KTransformers; the minimum Transformers version is 4.57.1.
Official requirements/examples show reasoning_content and remind users to handle intermediate state correctly in multi-turn thinking/tool calls.
These parameters are official starting recommendations and are not guaranteed to be optimal for a specific provider, task, or quantized model.
The extra_body fields may differ across APIs/engines; do not send official API fields directly to every OpenAI-compatible service.
reasoning_content is not a user-visible explanation and should be stored/filtered according to the provider's documentation; an explicit null may be rendered as text by the template.
Tool calls, EOS/grammar, and rate limiting are end-to-end system issues that model benchmarks cannot cover.
The official repository recommends using the Kimi Vendor Verifier to validate deployments; this is an important practice given differences among open-model providers.
Kimi K2.5