Claude Code

Claude Code is a programming agent product from Anthropic. Its interface, configuration options, and supported capabilities may change across versions. This guide describes a general integration approach: forwarding Claude Code model requests to the Kimi Code API through environment variables.

Before You Start

• Make sure you have subscribed to Kimi membership and activated Kimi Code benefits.
• Obtain an API Key:
  1. Go to the Kimi Code Console;
  2. Click "Create API Key", enter a name and confirm;
  3. Copy the generated key and keep it safe (the full key cannot be viewed again after closing the dialog).

Configuration

Claude Code is a command-line programming assistant launched by Anthropic. By configuring environment variables to connect it to Kimi's API endpoint, you can directly call Kimi Code's AI capabilities within Claude Code and enjoy the Kimi Code programming experience in a familiar terminal interface.

① Install Claude Code

For installation instructions, please refer to the Claude Code official documentation.

│

② Run Script to Skip Login

After installation, do not start Claude directly. Execute the following script in the terminal first to skip Anthropic's default login flow and clean up historical configuration:

node --eval "
// enable third party model support and fast mode
const claudeJsonFilePath = path.join(os.homedir(), '.claude.json');
if (fs.existsSync(claudeJsonFilePath)) {
    const content = JSON.parse(fs.readFileSync(claudeJsonFilePath, 'utf-8'));
    fs.writeFileSync(claudeJsonFilePath, JSON.stringify({ ...content, penguinModeOrgEnabled: true, hasCompletedOnboarding: true }, null, 2), 'utf-8');
} else {
    fs.writeFileSync(claudeJsonFilePath, JSON.stringify({ penguinModeOrgEnabled: true, hasCompletedOnboarding: true }), 'utf-8');
}

// delete old endpoint, credential and model id
const claudeSettingsJsonFilePath = path.join(os.homedir(), '.claude', 'settings.json');
if (fs.existsSync(claudeSettingsJsonFilePath)) {
    const content = JSON.parse(fs.readFileSync(claudeSettingsJsonFilePath, 'utf-8'));
    if (typeof content === 'object' && typeof content.env === 'object') {
        for (const element of [
            'ANTHROPIC_BASE_URL',
            'ANTHROPIC_API_KEY',
            'ANTHROPIC_AUTH_TOKEN',
            'ANTHROPIC_MODEL',
            'ANTHROPIC_SMALL_FAST_MODEL',
            'CLAUDE_CODE_SUBAGENT_MODEL',
            'ANTHROPIC_DEFAULT_FABLE_MODEL',
            'ANTHROPIC_DEFAULT_FABLE_MODEL_NAME',
            'ANTHROPIC_DEFAULT_OPUS_MODEL',
            'ANTHROPIC_DEFAULT_OPUS_MODEL_NAME',
            'ANTHROPIC_DEFAULT_SONNET_MODEL',
            'ANTHROPIC_DEFAULT_SONNET_MODEL_NAME',
            'ANTHROPIC_DEFAULT_HAIKU_MODEL',
            'ANTHROPIC_DEFAULT_HAIKU_MODEL_NAME',
            'ENABLE_TOOL_SEARCH',
            'CLAUDE_CODE_AUTO_COMPACT_WINDOW',
            'CLAUDE_CODE_EFFORT_LEVEL',
        ]) {
            delete content.env[element];
        }
        fs.writeFileSync(claudeSettingsJsonFilePath, JSON.stringify(content, null, 2), 'utf-8');
    }
}
"

The settings.json cleanup part only removes endpoint, credential, and model-related entries under env (leftovers there override environment variables exported in the terminal) — other settings are untouched. Also check ~/.zshrc, ~/.bashrc, and other shell config files for leftover ANTHROPIC_* exports (Windows users should check user environment variables) and remove them as well.

│

③ Configure API Access

First check your membership tier to confirm which models and context windows you can use:

Plan	Available Models	Available Context Limit
Andante	kimi-for-coding	262144
Moderato	k3, k3-256k, or kimi-for-coding	262144
Allegretto and above	k3, k3-256k, kimi-for-coding, kimi-for-coding-highspeed	1048576 for K3, 262144 for k3-256k, 262144 for the K2.7 Code series

Recommended model launch

k3-256k is now available. Within 256k context, it delivers the same results. k3 (1M) consumes about twice as much quota as k3-256k. Ideal for everyday Q&A, code completion, routine feature development, and single-file or small-file edits — video input is not supported. If switching from k3 (1M) to k3-256k, compress the context first before switching.

Two configuration methods are available — pick one, do not mix them: Method 1 writes to the settings.json config file and takes effect permanently regardless of how Claude Code is launched; Method 2 exports variables in the current terminal only, effective for that session.

Method 1: Write to settings.json (recommended, persistent)

The path of settings.json:

macOS / Linux

~/.claude/settings.json

Windows

C:\Users\<username>\.claude\settings.json

Write the following into the env field of that file (create the file if it does not exist):

K3-256K

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.kimi.com/coding/",
    "ANTHROPIC_API_KEY": "Your API Key",
    "ANTHROPIC_MODEL": "k3-256k",
    "ANTHROPIC_DEFAULT_FABLE_MODEL": "k3-256k",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "k3-256k",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "k3-256k",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "k3-256k",
    "CLAUDE_CODE_SUBAGENT_MODEL": "k3-256k",
    "CLAUDE_CODE_EFFORT_LEVEL": "high",
    "CLAUDE_CODE_AUTO_COMPACT_WINDOW": "262144",
    "CLAUDE_CODE_MAX_CONTEXT_TOKENS": "262144"
  }
}

K3 1M context

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.kimi.com/coding/",
    "ANTHROPIC_API_KEY": "Your API Key",
    "ANTHROPIC_MODEL": "k3[1m]",
    "ANTHROPIC_DEFAULT_FABLE_MODEL": "k3[1m]",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "k3[1m]",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "k3[1m]",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "k3[1m]",
    "CLAUDE_CODE_SUBAGENT_MODEL": "k3[1m]",
    "CLAUDE_CODE_EFFORT_LEVEL": "high",
    "CLAUDE_CODE_AUTO_COMPACT_WINDOW": "1048576",
    "CLAUDE_CODE_MAX_CONTEXT_TOKENS": "1048576"
  }
}

Restart Claude Code after saving for the changes to take effect.

Plaintext key risk

The API Key in settings.json is stored in plaintext — do not commit this file to a version-control repository or share it publicly with dotfiles. The file's env field overrides same-named variables exported in the terminal.

Method 2: Terminal environment variables (current session only)

K3-256K configuration:

macOS / Linux

export ANTHROPIC_BASE_URL=https://api.kimi.com/coding/
export ANTHROPIC_API_KEY=Your API Key

export ANTHROPIC_MODEL="k3-256k"
export ANTHROPIC_DEFAULT_FABLE_MODEL=$ANTHROPIC_MODEL
export ANTHROPIC_DEFAULT_OPUS_MODEL=$ANTHROPIC_MODEL
export ANTHROPIC_DEFAULT_SONNET_MODEL=$ANTHROPIC_MODEL
export ANTHROPIC_DEFAULT_HAIKU_MODEL=$ANTHROPIC_MODEL
export CLAUDE_CODE_SUBAGENT_MODEL=$ANTHROPIC_MODEL
export CLAUDE_CODE_EFFORT_LEVEL=high
export CLAUDE_CODE_AUTO_COMPACT_WINDOW=262144
export CLAUDE_CODE_MAX_CONTEXT_TOKENS=262144

claude

Windows

$env:ANTHROPIC_BASE_URL="https://api.kimi.com/coding/"
$env:ANTHROPIC_API_KEY="Your API Key"

$env:ANTHROPIC_MODEL="k3-256k"
$env:ANTHROPIC_DEFAULT_FABLE_MODEL=$env:ANTHROPIC_MODEL
$env:ANTHROPIC_DEFAULT_OPUS_MODEL=$env:ANTHROPIC_MODEL
$env:ANTHROPIC_DEFAULT_SONNET_MODEL=$env:ANTHROPIC_MODEL
$env:ANTHROPIC_DEFAULT_HAIKU_MODEL=$env:ANTHROPIC_MODEL
$env:CLAUDE_CODE_SUBAGENT_MODEL=$env:ANTHROPIC_MODEL
$env:CLAUDE_CODE_EFFORT_LEVEL="high"
$env:CLAUDE_CODE_AUTO_COMPACT_WINDOW="262144"
$env:CLAUDE_CODE_MAX_CONTEXT_TOKENS="262144"

claude

K3 1M context configuration:

The k3[1m] form is only needed for Claude Code env vars

k3[1m] (with the surrounding quotes) explicitly tells Claude Code to use a 1M context window. In any other scenario — API requests, the Model ID field of other third-party tools — just use k3.

macOS / Linux

export ANTHROPIC_BASE_URL=https://api.kimi.com/coding/
export ANTHROPIC_API_KEY=Your API Key

export ANTHROPIC_MODEL="k3[1m]"
export ANTHROPIC_DEFAULT_FABLE_MODEL=$ANTHROPIC_MODEL
export ANTHROPIC_DEFAULT_OPUS_MODEL=$ANTHROPIC_MODEL
export ANTHROPIC_DEFAULT_SONNET_MODEL=$ANTHROPIC_MODEL
export ANTHROPIC_DEFAULT_HAIKU_MODEL=$ANTHROPIC_MODEL
export CLAUDE_CODE_SUBAGENT_MODEL=$ANTHROPIC_MODEL
export CLAUDE_CODE_EFFORT_LEVEL=high
export CLAUDE_CODE_AUTO_COMPACT_WINDOW=1048576
export CLAUDE_CODE_MAX_CONTEXT_TOKENS=1048576

claude

Windows

$env:ANTHROPIC_BASE_URL="https://api.kimi.com/coding/"
$env:ANTHROPIC_API_KEY="Your API Key"

$env:ANTHROPIC_MODEL="k3[1m]"
$env:ANTHROPIC_DEFAULT_FABLE_MODEL=$env:ANTHROPIC_MODEL
$env:ANTHROPIC_DEFAULT_OPUS_MODEL=$env:ANTHROPIC_MODEL
$env:ANTHROPIC_DEFAULT_SONNET_MODEL=$env:ANTHROPIC_MODEL
$env:ANTHROPIC_DEFAULT_HAIKU_MODEL=$env:ANTHROPIC_MODEL
$env:CLAUDE_CODE_SUBAGENT_MODEL=$env:ANTHROPIC_MODEL
$env:CLAUDE_CODE_EFFORT_LEVEL="high"
$env:CLAUDE_CODE_AUTO_COMPACT_WINDOW="1048576"
$env:CLAUDE_CODE_MAX_CONTEXT_TOKENS="1048576"

claude

Configuration Reference

Claude Code internally uses different model tiers for different scenarios (main conversation, background summarization, sub-agents, etc.). Configuring only some of these variables will silently break the corresponding scenarios:

Variable	Purpose	Impact if missing or misconfigured
ANTHROPIC_BASE_URL	Routes model requests to the Kimi Code endpoint	Requests go to Anthropic's official endpoint and fail authentication
ANTHROPIC_API_KEY	Authenticates with your Kimi Code API Key	Returns a 401 authentication error
ANTHROPIC_MODEL	The model used for the main conversation	Falls back to Claude's default model name, which the Kimi Code endpoint does not recognize — model-not-found error
ANTHROPIC_DEFAULT_OPUS_MODEL / ANTHROPIC_DEFAULT_SONNET_MODEL / ANTHROPIC_DEFAULT_HAIKU_MODEL / ANTHROPIC_DEFAULT_FABLE_MODEL	Model names Claude Code picks for each task tier	Tasks on those tiers (e.g., haiku-tier background title generation and summarization) fail
CLAUDE_CODE_SUBAGENT_MODEL	The model used by sub-agents	Sub-agent tasks fail or degrade noticeably
CLAUDE_CODE_AUTO_COMPACT_WINDOW	Window size that triggers automatic context compaction	Must match the model's context: 1048576 for k3[1m], 262144 for the others. Too small compacts too early and loses context; too large triggers context-overflow errors
CLAUDE_CODE_MAX_CONTEXT_TOKENS	Maximum context token budget	Same as above — must match the selected model's context window
CLAUDE_CODE_EFFORT_LEVEL	Default thinking effort level; high is recommended for K3	Lower values may reduce quality on complex tasks

When switching models, replace the value of every model variable in your configuration with the new model name.

Switching thinking effort

After starting, type /effort in a session to switch thinking effort levels — no environment variable needed. K3 supports low / high / max; the mapping from Claude Code levels to K3 levels is:

Claude Code level	K3 level
low	low
medium	high (recommended)
high	high (recommended)
xhigh	max
max	max
Not set (default)	high

Note

Disabling thinking routes both K3 and K2.7 Code to K2.6. Keep Thinking on to use K3 / K2.7; for K2.7 Code the shortcut is Option+T on macOS and Alt+T on Windows / Linux.

If prompted whether to use this API key, confirm to proceed. Afterwards, follow the prompts to select your trusted project folder to complete the authorization.

│

④ Verify After Starting

After starting, enter /status. If the returned information shows Base URL as https://api.kimi.com/coding/, the configuration is successful. Even if the model name still appears as a Claude model, the actual calls are still made to the Kimi Code API.

│

Using the VS Code Extension

The extension ships with its own Claude Code binary and shares the config files under ~/.claude with the CLI. Follow these steps:

1. Complete the API setup in Configuration above.

2. Open the extension and start a new session. When the login page appears, click Run claude in terminal at the bottom:

   

3. In the terminal that opens, complete two confirmations: choose Yes, I trust this folder for the workspace, then 1. Yes to confirm your API key:

   

4. Quit VS Code completely (Cmd+Q on macOS) and reopen it — the extension is ready to use.

Without this terminal confirmation, the extension lacks the API key confirmation record and the login page pops up repeatedly when you send a message.

FAQ

Changes to the configuration don't take effect

Check whether ~/.claude/settings.json has leftover entries under env (they override terminal environment variables) — you can run the cleanup script from Step ②. Also note that variables exported in a terminal only apply to that session and must be set again after opening a new terminal; if you wrote to settings.json, make sure you restarted Claude Code after editing.

401 authentication error

Check whether ANTHROPIC_API_KEY is a valid Kimi Code API Key — note that the full key is only shown once at creation time.

Model not found

Check the spelling of each model variable (e.g. k3-256k, k3[1m]), and make sure there are no extra spaces or quotes.

Background tasks or sub-agents fail

Usually ANTHROPIC_DEFAULT_HAIKU_MODEL, ANTHROPIC_DEFAULT_FABLE_MODEL, or CLAUDE_CODE_SUBAGENT_MODEL is not configured — the corresponding scenario requested a model name the Kimi Code endpoint does not recognize. See the Configuration Reference and fill in the missing entries.

The VS Code extension keeps showing the login page

The extension is missing the API key confirmation record. Click Run claude in terminal at the bottom of the login page, complete the trust-folder and API key confirmations in the terminal, then quit VS Code completely (Cmd+Q on macOS) and reopen. See Using the VS Code Extension.