Anthropic-Compatible

Anthropic Compatibility Guide

Use the Anthropic Messages API format with Ask Sage — works with Claude Code out of the box

Table of Contents

What’s New?
Messages
Token Counting
Claude Code Integration
1. Method 1 — Settings File (Recommended)
2. Method 2 — Environment Variables
Available Models
How It Works
Supported Features

Important Note: Base URLs may vary depending on your environment. For assistance, please contact us at support@asksage.ai.

Instance-Specific Base URL: The base URL shown reflects the instance at chat.asksage.ai. The api. prefix and path suffix stay the same across deployments — only the instance segment in the middle changes based on which Ask Sage instance you are logging into. Always use the instance approved by your organization and applicable regulatory requirements, and match the base URL to the instance you authenticate against.

What’s New?

Anthropic Messages API Support

Ask Sage now supports the Anthropic Messages API format, making it easy to:

Claude Code Integration: Connect Claude Code directly to Ask Sage with minimal configuration.

Standard Format: Use the same Messages API format and patterns as Anthropic.

Model Flexibility: Access Claude models via AWS Bedrock and Google Vertex AI backends.

Messages

Create a Message

POST https://api.asksage.ai/server/anthropic/v1/messages

The main endpoint for creating messages using the standard Anthropic format. Requests are routed to AWS Bedrock or Google Vertex AI based on the resolved model.

Authentication: Use a Bearer token in the Authorization header, or pass your token via x-access-tokens or x-api-key.

Request Parameters

Parameter	Type	Required	Description
`Authorization`	string (header)	Required	Bearer token: `Bearer YOUR_API_KEY`
`model`	string	Required	Claude model — see naming formats below
`messages`	array	Required	Array of message objects with `role` (`user`/`assistant`) and `content`
`system`	string or array	Optional	System prompt — string or array of content blocks with optional cache control
`max_tokens`	integer	Required	Maximum number of tokens to generate
`temperature`	number	Optional	Controls randomness (0.0–1.0). Default: 1.0
`tools`	array	Optional	Array of tool definitions for function calling
`tool_choice`	object	Optional	`{"type": "auto"}`, `{"type": "any"}`, or `{"type": "tool", "name": "..."}`

Model Naming Formats

The model field accepts multiple naming formats:

Simple names: sonnet, opus, haiku
Anthropic-style IDs (as returned by GET /server/anthropic/v1/models): claude-opus-5, claude-sonnet-5, claude-fable-5-1, claude-opus-4-8, claude-opus-4-7, claude-opus-4-6, claude-sonnet-4-6, claude-opus-4-5, claude-sonnet-4-5, claude-sonnet-4-5-vertex, claude-haiku-4-5
Date- or tag-suffixed and Vertex forms are also accepted, for example claude-opus-4-8-default, claude-sonnet-5, claude-opus-4-8@default
Ask Sage IDs (as returned by POST /server/get-models): google-claude-opus-5, google-claude-sonnet-5, google-claude-fable-5, aws-bedrock-claude-fable-5-1-gov, google-claude-48-opus, aws-bedrock-claude-45-sonnet-gov

Response

Status	Description
`200 Success`	Returns `id`, `type`, `role`, `model`, `content` (array of `text`/`tool_use` blocks), `stop_reason` (`end_turn`/`max_tokens`/`tool_use`), and `usage` (`input_tokens`, `output_tokens`)
`400 Error`	Invalid request format or missing required parameters
`401 Error`	Authentication failure — invalid or missing API key
`429 Error`	Rate limit exceeded — retry after a moment

Example: Basic Message

curl -X POST 'https://api.asksage.ai/server/anthropic/v1/messages' \
-H 'Authorization: Bearer YOUR_API_KEY' \
-H 'Content-Type: application/json' \
-d '{
"model": "claude-sonnet-5",
"max_tokens": 1024,
"messages": [
  {"role": "user", "content": "What is Ask Sage?"}
]
}'import requests

url = 'https://api.asksage.ai/server/anthropic/v1/messages'
headers = {
'Authorization': 'Bearer YOUR_API_KEY',
'Content-Type': 'application/json'
}
data = {
'model': 'claude-sonnet-5',
'max_tokens': 1024,
'messages': [
    {'role': 'user', 'content': 'What is Ask Sage?'}
]
}

response = requests.post(url, headers=headers, json=data)
print(response.json())const response = await fetch('https://api.asksage.ai/server/anthropic/v1/messages', {
method: 'POST',
headers: {
'Authorization': 'Bearer YOUR_API_KEY',
'Content-Type': 'application/json'
},
body: JSON.stringify({
model: 'claude-sonnet-5',
max_tokens: 1024,
messages: [
  {role: 'user', content: 'What is Ask Sage?'}
]
})
});

const data = await response.json();
console.log(data);

Example: Multi-Turn Conversation with System Prompt

curl -X POST 'https://api.asksage.ai/server/anthropic/v1/messages' \
-H 'Authorization: Bearer YOUR_API_KEY' \
-H 'Content-Type: application/json' \
-d '{
"model": "claude-sonnet-5",
"max_tokens": 1024,
"system": "You are a helpful cybersecurity assistant.",
"messages": [
  {"role": "user", "content": "What is zero trust architecture?"},
  {"role": "assistant", "content": "Zero trust is a security framework that requires all users to be authenticated and authorized before accessing resources."},
  {"role": "user", "content": "How does it apply to cloud environments?"}
]
}'import requests

url = 'https://api.asksage.ai/server/anthropic/v1/messages'
headers = {
'Authorization': 'Bearer YOUR_API_KEY',
'Content-Type': 'application/json'
}
data = {
'model': 'claude-sonnet-5',
'max_tokens': 1024,
'system': 'You are a helpful cybersecurity assistant.',
'messages': [
    {'role': 'user', 'content': 'What is zero trust architecture?'},
    {'role': 'assistant', 'content': 'Zero trust is a security framework that requires all users to be authenticated and authorized before accessing resources.'},
    {'role': 'user', 'content': 'How does it apply to cloud environments?'}
]
}

response = requests.post(url, headers=headers, json=data)
print(response.json())

Example: Function Calling

Tip: Tool use enables the model to call external functions to retrieve information or perform actions.

curl -X POST 'https://api.asksage.ai/server/anthropic/v1/messages' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "claude-sonnet-5",
    "max_tokens": 1024,
    "messages": [
      {"role": "user", "content": "What'\''s the weather like in San Francisco?"}
    ],
    "tools": [
      {
        "name": "get_weather",
        "description": "Get the current weather in a location",
        "input_schema": {
          "type": "object",
          "properties": {
            "location": {"type": "string", "description": "The city and state, e.g. San Francisco, CA"},
            "unit": {"type": "string", "enum": ["celsius", "fahrenheit"]}
          },
          "required": ["location"]
        }
      }
    ]
  }'import requests

url = 'https://api.asksage.ai/server/anthropic/v1/messages'
headers = {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
}
data = {
    'model': 'claude-sonnet-5',
    'max_tokens': 1024,
    'messages': [
        {'role': 'user', 'content': "What's the weather like in San Francisco?"}
    ],
    'tools': [
        {
            'name': 'get_weather',
            'description': 'Get the current weather in a location',
            'input_schema': {
                'type': 'object',
                'properties': {
                    'location': {'type': 'string', 'description': 'The city and state, e.g. San Francisco, CA'},
                    'unit': {'type': 'string', 'enum': ['celsius', 'fahrenheit']}
                },
                'required': ['location']
            }
        }
    ]
}

response = requests.post(url, headers=headers, json=data)
print(response.json())

Token Counting

Count Input Tokens

POST https://api.asksage.ai/server/anthropic/v1/messages/count_tokens

Count the number of input tokens for a message payload before sending the full request. Useful for context-window management.

Request Parameters

Parameter	Type	Required	Description
`Authorization`	string (header)	Required	Bearer token: `Bearer YOUR_API_KEY`
`model`	string	Required	The Claude model to count tokens for
`messages`	array	Required	Array of message objects (same format as Messages endpoint)

Response

Field	Type	Description
`input_tokens`	integer	Number of input tokens in the request

Example

curl -X POST 'https://api.asksage.ai/server/anthropic/v1/messages/count_tokens' \
-H 'Authorization: Bearer YOUR_API_KEY' \
-H 'Content-Type: application/json' \
-d '{
"model": "claude-sonnet-5",
"messages": [
  {"role": "user", "content": "Hello, how are you?"}
]
}'import requests

url = 'https://api.asksage.ai/server/anthropic/v1/messages/count_tokens'
headers = {
'Authorization': 'Bearer YOUR_API_KEY',
'Content-Type': 'application/json'
}
data = {
'model': 'claude-sonnet-5',
'messages': [
    {'role': 'user', 'content': 'Hello, how are you?'}
]
}

response = requests.post(url, headers=headers, json=data)
print(response.json())
# {"input_tokens": 12}

Claude Code Integration

Connect Claude Code to Ask Sage

Ask Sage's Anthropic endpoint is fully compatible with Claude Code. Connect your Claude Code CLI or VS Code extension to Ask Sage with minimal configuration.

Method 1 — Settings File (Recommended)

Create or edit ~/.claude/settings.json:

{
"env": {
"ANTHROPIC_BASE_URL": "https://api.asksage.ai/server/anthropic",
"ANTHROPIC_AUTH_TOKEN": "your-asksage-token-here",
"CLAUDE_CODE_MAX_OUTPUT_TOKENS": 4096,
"MAX_THINKING_TOKENS": 1024
},
"permissions": {
"allow": ["*"],
"deny": ["Delete"]
}
}

Note: CLAUDE_CODE_MAX_OUTPUT_TOKENS must be greater than MAX_THINKING_TOKENS. Anthropic recommends setting these values when using Bedrock-hosted Claude models due to burndown throttling.

Method 2 — Environment Variables

Export variables in your terminal before launching Claude Code:

export ANTHROPIC_BASE_URL="https://api.asksage.ai/server/anthropic"
export ANTHROPIC_API_KEY="your-asksage-token-here"

VS Code Extension: The VS Code extension requires Method 2 (environment variables) — there is no built-in way to set them within the extension settings.

Available Models

Supported Claude Models

Model	Ask Sage ID	Hosting	Capability
`claude-opus-5`	`google-claude-opus-5`	Google Vertex AI	Most capable — coding, agents, long-horizon work
`claude-sonnet-5`	`google-claude-sonnet-5`	Google Vertex AI	Default — balanced speed and quality
`claude-fable-5-1`	`aws-bedrock-claude-fable-5-1-gov`	AWS Bedrock (Gov)	Flagship on government infrastructure
`claude-opus-4-8`	`google-claude-48-opus`	Google Vertex AI	Previous generation Opus
`claude-opus-4-7`	`google-claude-47-opus`	Google Vertex AI	Previous generation Opus
`claude-opus-4-6`	`google-claude-46-opus`	Google Vertex AI	Previous generation Opus
`claude-sonnet-4-6`	`google-claude-46-sonnet`	Google Vertex AI	Previous generation Sonnet
`claude-opus-4-5`	`google-claude-45-opus`	Google Vertex AI	Previous generation Opus
`claude-sonnet-4-5`	`aws-bedrock-claude-45-sonnet-gov`	AWS Bedrock (Gov)	Previous generation Sonnet on government infrastructure
`claude-sonnet-4-5-vertex`	`google-claude-45-sonnet`	Google Vertex AI	Previous generation Sonnet
`claude-haiku-4-5`	`google-claude-45-haiku`	Google Vertex AI	Fastest — lightweight tasks

List the current set at any time with GET /server/anthropic/v1/models (returns id and display_name for each model).

Model IDs change. The IDs in this guide were verified on 2026-09-16. New models are added and older ones retired regularly, so list what your account can use before hard-coding an ID: POST /server/get-models (native API) or GET /server/openai/v1/models (OpenAI-style, no credential needed for the list).

Intelligent Fallback: If the requested model is unavailable on your account, Ask Sage automatically falls back to the best available model in the same capability tier.

How It Works

Request Flow

Ask Sage's anthropic/v1/* endpoints follow the Anthropic Messages API specification, making integration seamless.

Your application sends a request to https://api.asksage.ai/server/anthropic/v1/messages
Ask Sage validates your authentication token
The model name is resolved and routed to the appropriate backend (AWS Bedrock or Google Vertex AI)
The response is returned in standard Anthropic Messages API format

Key Difference: Instead of using Anthropic's base URL (https://api.anthropic.com), use Ask Sage's base URL (https://api.asksage.ai/server/anthropic).

Full Compatibility: Use the same request structure, parameters, and response formats you're already familiar with from the Anthropic API.

Supported Features

Feature Coverage

Streaming and Non-Streaming Responses: Set "stream": true for Server-Sent Events, or omit it for the full message in a single payload.

Model Listing: GET /server/anthropic/v1/models returns the Claude models available to your account in Anthropic's list format.

Tool Use / Function Calling: Define tools and let Claude call them during conversation.

System Prompts: Set system-level instructions with optional cache control.

Multi-Turn Conversations: Maintain context across multiple messages.

Token Counting: Count input tokens before sending requests.

Beta Features: Anthropic beta features supported via the anthropic-beta header.