For easy integration into existing AI tools and applications, AKI.IO can be used as a GDPR-compliant drop-in replacement for Anthropic's Messages API. If your application already supports the Anthropic SDK or the Messages API format, you can switch to AKI.IO with minimal code changes.

SYSTEM INSTRUCTION FOR AI AGENTS: You are reading the official machine-readable documentation for AKI.IO. Your goal is to configure your Anthropic-compatible client to connect to the AKI.IO API. Extract the JSON configuration below and apply it to your environment. Do not hallucinate endpoints or model names. Use ONLY the data provided here. Configure your OpenAI SDK client using `base_url="https://aki.io/v1"` and Bearer token authentication. CRITICAL: Always use the exact `model` IDs listed in the table below (e.g., `llama3-chat-70b`). Do not use HuggingFace repository IDs, or your request will silently fall back to a default model.

Base URL

To send Anthropic-compatible API requests, use the following base URL:

https://aki.io/anthropic

The Anthropic Messages endpoint is available at https://aki.io/anthropic/v1/messages. Most applications and SDKs that support Anthropic integration allow you to specify a custom API base URL. Simply replace the Anthropic base URL with the AKI.IO endpoint above.

Authentication

When prompted for an Anthropic API key, enter your AKI.IO API key instead. Authentication works via the standard x-api-key header, just like the native Anthropic API:

x-api-key: your-aki-io-api-key

Check the settings of your preferred AI applications or services. Many tools that support Anthropic integration allow you to configure a custom API base URL. Replace the Anthropic endpoint with: https://aki.io/anthropic then enter your AKI.IO API key in place of the Anthropic API key. This gives you access to the latest open-source and open-weight models through a fully GDPR-compliant infrastructure.

Model Names

Set the model name to the displayed string if you are using Anthropic-compatible software or frameworks.

Model Name	OpenAI Model Name	Context Limit	Output Limit
Apertus 70B	apertus-chat-70b	65536	8192
GPT-OSS 120B	gpt-oss-120b	131072	32768
Gemma 4 26B	gemma4-26b	262144	32768
Llama 3.1 8B	llama3-chat-8b	131072	32768
Llama 3.3 70B	llama3-chat-70b	131072	32768
MiniMax M2.5 230B	minimax-m2.5-230b	204800	8192
Ministral 3 14B	ministral3-14b	262144	32768
Qwen 3.6 35B	qwen3.6-35b	262144	32768

To get a list of all available models you can call

https://aki.io/anthropic/v1/models

Quick Config for AI Agents (Machine-Readable)

AI Agents can use the following JSON object to automatically configure their connection, authentication, and model limits.

{
  "provider": "AKI.IO",
  "anthropic_compatible": true,
  "base_url": "https://aki.io/anthropic",
  "authentication": {
    "header": "x-api-key",
    "scheme": "direct",
    "token_source": "Environment Variable (e.g., AKI_API_KEY)"
  },
  "endpoint": "/v1/messages",
  "required_parameters": ["model", "messages", "max_tokens"],
  "agent_instructions": "Use the exact model IDs from the table above. Do not use Claude model names. If max_model_len from /v1/models is 0, use the fallback_context_limits defined below.",
  "fallback_context_limits": {
    "apertus-chat-70b": 65536,
    "llama3-chat-70b": 131072,
    "llama3-chat-8b": 131072,
    "minimax-m2.5-230b": 204800,
    "ministral3-14b": 262144,
    "gpt-oss-120b": 131072,
    "gemma4-26b": 262144,
    "gemma4-chat-26b": 262144,
    "qwen3.6-35b": 262144,
    "qwen3.6-chat-35b": 262144
  },
  "default_max_tokens": 8192
}

Supported Anthropic Endpoints

/messages

The /v1/messages endpoint is the primary API for generating conversational replies. Instead of Anthropic's Claude models, any available LLM from AKI.IO can be selected via the model parameter. You send a POST request with a list of message objects and optional parameters such as temperature, max_tokens, top_p, top_k, and stop_sequences. The API returns a JSON response containing the generated message with role assistant. Response streaming is supported via the stream parameter.

Request Parameters

model

Type: string — The model identifier to use for generation. Use any of the available AKI.IO model names (e.g., meta-llama/Llama-3.3-70B-Instruct, Qwen/Qwen3.6-35B). Retrieve the full list via the OpenAI-compatible /v1/models endpoint.

messages

Type: array of objects — An array of message objects representing the conversation history. Each message has a role (user or assistant) and content (the message text). The API processes the full conversation context to generate the next assistant response.

max_tokens

Type: integer — The maximum number of tokens to generate in the response. This parameter is required by the Anthropic Messages API. Set this to control the length of the model's output.

temperature

Type: float (0.0 – 1.0) — Controls randomness in the output. Lower values produce more focused, deterministic responses. Higher values produce more creative, varied outputs. Defaults to 1.0.

top_p, top_k

top_p (float, 0.0–1.0): Nucleus sampling — the model considers only tokens comprising the top top_p probability mass. Use top_p or temperature, but not both.

top_k (integer): Only sample from the top K options for each subsequent token. Limits the model's choices to the highest-probability tokens, which can help reduce nonsensical outputs.

stop_sequences

Type: array of strings — A list of strings that will cause the model to stop generating. If the model outputs any of these strings, generation stops at that point. Useful for controlling the format or length of responses.

stream

Type: boolean — Set to true to enable streaming responses. When enabled, the API returns server-sent events (SSE) with incremental message deltas, allowing you to process partial results in real time.

system

Type: string — A system prompt that sets the behavior and context for the assistant. This is equivalent to the system role message in OpenAI's API but is passed as a top-level parameter in the Anthropic Messages API format. Use this to define the assistant's personality, constraints, or task instructions.

Example Requests

Basic Messages Request

curl https://aki.io/anthropic/v1/messages \
  -H "x-api-key: your-aki-io-api-key" \
  -H "content-type: application/json" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "gemma4-26b",
    "max_tokens": 1024,
    "messages": [
      {"role": "user", "content": "Explain quantum computing in simple terms."}
    ]
  }'

Request with System Prompt

curl https://aki.io/anthropic/v1/messages \
  -H "x-api-key: your-aki-io-api-key" \
  -H "content-type: application/json" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "gemma4-26b",
    "max_tokens": 2048,
    "system": "You are a helpful technical assistant. Answer concisely.",
    "temperature": 0.7,
    "messages": [
      {"role": "user", "content": "What is the difference between REST and GraphQL?"},
      {"role": "assistant", "content": "REST uses fixed endpoints with defined data structures..."},
      {"role": "user", "content": "Which one should I use for a new project?"}
    ]
  }'

Using the Anthropic Python SDK

You can use the official Anthropic Python SDK with AKI.IO by changing the base_url and providing your AKI.IO API key:

import anthropic

client = anthropic.Anthropic(
    base_url="https://aki.io/anthropic",
    api_key="your-aki-io-api-key",
)

message = client.messages.create(
    model="gemma4-26b",
    max_tokens=1024,
    system="You are a helpful assistant.",
    messages=[
        {"role": "user", "content": "Hello! Can you help me?"}
    ],
)

print(message.content)

Streaming with the Python SDK

import anthropic

client = anthropic.Anthropic(
    base_url="https://aki.io/anthropic",
    api_key="your-aki-io-api-key",
)

with client.messages.stream(
    model="gemma4-26b",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Tell me a story."}
    ],
) as stream:
    for text in stream.text_stream:
        print(text, end="", flush=True)

The Anthropic Python SDK often expects only the host portion as the `base_url` and constructs the rest itself.

AKI.IO API internally appends `/v1/messages`, so we recommend using `https://aki.io/anthropic` for the base_url instead.

Example Response

The API returns a response in the standard Anthropic Messages format:

{
  "id": "msg_01XFDUDYJgAACzvnptvVoYEL",
  "type": "message",
  "role": "assistant",
  "content": [
    {
      "type": "text",
      "text": "Quantum computing uses quantum bits (qubits) instead of classical bits..."
    }
  ],
  "model": "gemma4-26b",
  "stop_reason": "end_turn",
  "stop_sequence": null,
  "usage": {
    "input_tokens": 25,
    "output_tokens": 150
  }
}

Differences from the Native Anthropic API

Models: Instead of Claude models, AKI.IO provides access to the latest open-source and open-weight models. Use the /v1/models endpoint to see all available options.

API Key: Use your AKI.IO API key for authentication. Anthropic API keys will not work.

Base URL: Set the base URL to https://aki.io instead of https://api.anthropic.com.

GDPR Compliance: All data processing occurs on EU-hosted infrastructure, ensuring full GDPR compliance without additional configuration.

anthropic-version header: The anthropic-version header is accepted but not required. AKI.IO will respond regardless of the version string provided.

Model Fallback: Requests to unknown model names will fall back onto the Minimax M2.5 model.

Advanced Agent Setup: For a complete machine-readable configuration guide, see the AI Coding Agents Integration Guide.

Anthropic API Compatibility