Skip to content
CheapestInference
BlogReports

How to use the Kimi K3 API: key, snippets, and unlimited access

Kimi K3 is live on CheapestInference: Moonshot’s flagship — the first open-weight model to outscore the Claude Opus tier on the Artificial Analysis Intelligence Index — served through an OpenAI- and Anthropic-compatible API with unlimited usage at a flat monthly price, from $149/mo (live availability — seats are very limited). This is the practical guide: get access, call it, wire it into your coding agent.

1. Get access

Section titled “1. Get access”

Three realistic routes to K3 over an API today:

  1. Per-token, from Moonshot — $3.00 per 1M input tokens ($0.30 cached) and $15.00 per 1M output. Ideal for evaluation and light use; expensive fast for agent workloads.
  2. Kimi memberships — Moonshot’s own plans bundle K3 access with request quotas per 5-hour and weekly windows (new signups have been intermittently paused since launch).
  3. Unlimited time-block subscription (this guide) — reserve one or more daily 8-hour blocks on the Flagship Pool and use K3 with no token caps during your hours. From $149/mo per block; all three blocks = 24/7.

For the subscription route: create an account, subscribe to the Flagship Pool, and mint an API key at cheapestinference.com/keys. Model id: kimi-k3.

2. Call Kimi K3

Section titled “2. Call Kimi K3”

curl:

Terminal window
curl https://api.cheapestinference.com/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "kimi-k3", "messages": [{"role": "user", "content": "Hello"}]}'

OpenAI SDK (Python):

from openai import OpenAI


client = OpenAI(
    base_url="https://api.cheapestinference.com/v1",
    api_key="sk-...",  # your subscriber key
)


response = client.chat.completions.create(
    model="kimi-k3",
    messages=[{"role": "user", "content": "Refactor this function..."}],
)
print(response.choices[0].message.content)

K3 is a reasoning model, but reasoning is off by default — you get fast, direct answers. Turn it on per request with "thinking": {"type": "enabled"} or reasoning_effort (low / high / max — K3’s deepest tier). With reasoning on, give it a generous max_tokens so long answers don’t truncate mid-thought, and stream (stream: true) for responsive UIs.

3. Run it in Claude Code

Section titled “3. Run it in Claude Code”

The API also speaks the Anthropic Messages format, so Claude Code works out of the box:

Terminal window
export ANTHROPIC_BASE_URL="https://api.cheapestinference.com/anthropic"
export ANTHROPIC_AUTH_TOKEN="sk-..."   # your subscriber key
export ANTHROPIC_MODEL="kimi-k3"
export ANTHROPIC_SMALL_FAST_MODEL="kimi-k3"

Start claude as usual — every request now runs on K3 with no per-token meter. The same key works in Cline, Roo Code, Continue, and any client that accepts a custom OpenAI base URL (setup guides).

What it costs, honestly

Section titled “What it costs, honestly”

At list price, a coding agent that burns 100M tokens a month on K3 costs roughly $200–400 per-token, depending on your cache-hit and output mix — and heavy agentic users go far beyond that. A Flagship block at $149/mo covers your working day; all three blocks cover 24/7. The trade-offs: during your reserved hours usage is truly unlimited, each subscription runs one request at a time (fair use), and outside your blocks the key doesn’t serve. Full pricing detail: Plans & Limits · Kimi K3 API docs.

Seats on the Flagship Pool are very limited — when a block sells out it’s gone until someone leaves. Check live availability →

CheapestInference serves Kimi K3 (Flagship Pool), Kimi K2.7, GLM 5.2, and MiniMax M3 (Frontier Pool) and DeepSeek V4 Flash and MiMo v2.5 (Core Pool) through one OpenAI- and Anthropic-compatible API on unlimited time-block subscriptions. See the pools or get started.

Tags: