Claude Code Integration with Knox

This guide explains how to use Claude Code with Knox API.

Quick Start

Step 1: Get Your Knox API Key

1. Log in to your Knox dashboard
2. Navigate to Tokens section
3. Create a new API token or use an existing one
4. Copy the API key (format: sk-xxxx...)

Step 2: Configure Claude Code

Add these environment variables to your shell profile (~/.bashrc, ~/.zshrc, or ~/.config/fish/config.fish):

# Production (api.knox.chat)
export ANTHROPIC_BASE_URL="https://api.knox.chat"
export ANTHROPIC_AUTH_TOKEN="sk-your-knox-api-key"
export ANTHROPIC_API_KEY=""  # Important: Must be explicitly empty

Important: Do not put these in a project-level .env file. The native Claude Code installer does not read standard .env files.

Step 3: Start Claude Code

Navigate to your project directory and start Claude Code:

cd /path/to/your/project
claude

Step 4: Verify Connection

Run the /status command inside Claude Code to verify your connection:

> /status
Auth token: ANTHROPIC_AUTH_TOKEN
Anthropic base URL: https://api.knox.chat

Supported Models

Knox automatically maps Claude Code model names to the correct Knox models:

• anthropic/claude-haiku-4.5
• anthropic/claude-sonnet-4.6
• anthropic/claude-opus-4.6

Overriding Default Models

You can configure Claude Code to use specific models by setting environment variables:

export ANTHROPIC_DEFAULT_SONNET_MODEL="anthropic/claude-sonnet-4.6"
export ANTHROPIC_DEFAULT_OPUS_MODEL="anthropic/claude-opus-4.6"
export ANTHROPIC_DEFAULT_HAIKU_MODEL="anthropic/claude-haiku-4.5"

How It Works

Knox provides an Anthropic-compatible API layer:

1. Direct Connection: When you set ANTHROPIC_BASE_URL to https://api.knox.chat, Claude Code sends requests to the /v1/messages endpoint using its native Anthropic protocol.

2. Format Conversion: Knox automatically converts between Anthropic Messages API format and OpenAI Chat Completions format internally.

3. Model Routing: Requests are routed through Knox's intelligent model routing system to the best available provider.

4. Billing: Usage is tracked and billed through your Knox account. You can view usage in your Knox dashboard.

Authentication

Knox supports two authentication methods for Claude Code compatibility:

1. x-api-key Header (Anthropic style):

   x-api-key: sk-your-api-key

2. Authorization Header (OpenAI style):

   Authorization: Bearer sk-your-api-key

Claude Code can use either method via the ANTHROPIC_AUTH_TOKEN environment variable.

API Endpoints

Endpoint	Description
POST /v1/messages	Anthropic Messages API (Claude Code uses this)
POST /v1/completions	OpenAI Completions API (text completions)
POST /v1/chat/completions	OpenAI Chat Completions API
GET /v1/models	List available models

Completions API

Knox also supports the OpenAI Completions API for text completion tasks. This is useful for legacy integrations or simple text generation.

Request Format

{
  "model": "model-name",
  "prompt": "Your text prompt here",
  "max_tokens": 100,
  "temperature": 0.7,
  "stream": false
}

Request Parameters

Parameter	Type	Required	Description
model	String	Yes	The model ID to use
prompt	String	Yes	The text prompt to complete
max_tokens	Integer	No	Maximum tokens to generate
temperature	Double	No	Sampling temperature (0-2)
top_p	Double	No	Nucleus sampling (0-1)
top_k	Integer	No	Top-k sampling
stream	Boolean	No	Enable streaming (default: false)
seed	Integer	No	Seed for deterministic output
frequency_penalty	Double	No	Frequency penalty (-2 to 2)
presence_penalty	Double	No	Presence penalty (-2 to 2)
repetition_penalty	Double	No	Repetition penalty (0-2)
stop	Array	No	Stop sequences

Example Request

curl -X POST https://api.knox.chat/v1/completions \
  -H "Authorization: Bearer sk-your-api-key" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-sonnet-4.6",
    "prompt": "Once upon a time",
    "max_tokens": 100
  }'

Example Response

{
  "id": "cmpl-abc123",
  "choices": [
    {
      "text": " in a land far away, there lived a curious little fox...",
      "index": 0,
      "finish_reason": "stop"
    }
  ]
}

SDK Usage

import openai

client = openai.OpenAI(
    base_url="https://api.knox.chat/v1",
    api_key="sk-your-knox-api-key",
)

response = client.completions.create(
    model="anthropic/claude-sonnet-4.6",
    prompt="Write a haiku about programming:",
    max_tokens=50
)

print(response.choices[0].text)

Features Supported

• ✅ Streaming responses
• ✅ Tool use (function calling)
• ✅ Multi-turn conversations
• ✅ System prompts
• ✅ Image inputs (base64 and URL)
• ✅ Extended thinking (Claude 3.5+)
• ✅ Stop sequences
• ✅ Temperature and top-p controls
• ✅ Prompt caching with cache_control (5-minute and 1-hour TTL)
• ✅ Cache token tracking in usage response

Prompt Caching

Knox supports Anthropic's prompt caching feature to reduce costs on repeated prompts. Cache control is passed through to Knox for Anthropic models.

Cache Control Syntax

Add cache_control to content blocks you want to cache:

{
  "role": "user",
  "content": [
    {
      "type": "text",
      "text": "Very long document to cache...",
      "cache_control": {
        "type": "ephemeral"
      }
    },
    {
      "type": "text",
      "text": "Question about the document"
    }
  ]
}

Cache TTL Options

• 5 minutes (default): {"type": "ephemeral"}
• 1 hour: {"type": "ephemeral", "ttl": "1h"}

Cache Savings

The response usage field includes cache token information:

• cache_creation_input_tokens: Tokens written to cache (1.25x cost)
• cache_read_input_tokens: Tokens read from cache (0.1x cost)

Troubleshooting

Authentication Errors

• Ensure ANTHROPIC_API_KEY is set to an empty string (""), not unset
• Verify your Knox API key is valid and has sufficient quota
• Check that your token has access to Claude models

Connection Errors

• Verify the ANTHROPIC_BASE_URL is correct:
  • Production: https://api.knox.chat
• Ensure there's no trailing slash in the URL

Model Not Found

• Make sure your token has access to the Claude model you're trying to use
• Check available models in your Knox Models List

Example: Programmatic Usage

If you're using the Anthropic SDK programmatically:

import anthropic

client = anthropic.Anthropic(
    base_url="https://api.knox.chat",
    api_key="sk-your-knox-api-key",
)

message = client.messages.create(
    model="anthropic/claude-sonnet-4.6",
    max_tokens=4096,
    messages=[
        {"role": "user", "content": "Hello, Claude!"}
    ]
)

print(message.content)

import Anthropic from '@anthropic-ai/sdk';

const client = new Anthropic({
  baseURL: 'https://api.knox.chat',
  apiKey: 'sk-your-knox-api-key',
});

const message = await client.messages.create({
  model: 'anthropic/claude-sonnet-4.6',
  max_tokens: 4096,
  messages: [
    { role: 'user', content: 'Hello, Claude!' }
  ],
});

console.log(message.content);