API Reference

RuAPI supports two API protocols simultaneously: classic OpenAI-compatible and native Anthropic Claude-compatible. The same API key works with both.

OpenAI protocol

POST /v1/chat/completions — industry standard, supported by virtually all SDKs and frameworks.

Claude protocol

POST /v1/messages — native Anthropic format with thinking blocks and MCP support.

Quick reference:

	OpenAI-compatible	Anthropic
`base_url`	`https://www.ruapi.ai/v1`	`https://www.ruapi.ai` (no `/v1`)
Endpoint	`POST /v1/chat/completions`	`POST /v1/messages`
Auth header	`Authorization: Bearer sk-...`	`x-api-key: sk-...`

Base URL

The address depends on the protocol — this is the #1 thing people get wrong: OpenAI-compatible — with /v1:

https://www.ruapi.ai/v1

Anthropic — without /v1 (the SDK appends /v1/messages itself):

https://www.ruapi.ai

The endpoint tables below show full paths from the domain root. Auth via the Authorization: Bearer sk-... header (x-api-key also works on /v1/messages).

For Anthropic, do not add /v1 to the base_url — an extra /v1 returns a 404.

OpenAI protocol

Use this protocol if your code already uses the official OpenAI SDK or a compatible framework (LangChain, LlamaIndex, Vercel AI SDK, etc.).

Endpoint

POST https://www.ruapi.ai/v1/chat/completions

Compatibility

The request/response format matches OpenAI’s Chat Completions API. Supported:

messages (with roles system / user / assistant / tool)
model — name of any model in the catalog (Claude/Gemini/Grok/Qwen/MiniMax/GLM included — we convert on the fly)
stream: true for streaming responses (Server-Sent Events)
tools / tool_choice for function calling
temperature, top_p, max_tokens and other parameters

Example: Python (OpenAI SDK)

from openai import OpenAI

client = OpenAI(
    api_key="sk-YOUR_KEY",
    base_url="https://www.ruapi.ai/v1",
)

response = client.chat.completions.create(
    model="claude-opus-4-8",  # see www.ruapi.ai for available models
    messages=[
        {"role": "system", "content": "You are a friendly assistant."},
        {"role": "user", "content": "Hello! What can you do?"},
    ],
    temperature=0.7,
)

print(response.choices[0].message.content)
print(f"Tokens used: {response.usage.total_tokens}")

Example: Node.js (OpenAI SDK)

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: "sk-YOUR_KEY",
  baseURL: "https://www.ruapi.ai/v1",
});

const response = await client.chat.completions.create({
  model: "claude-opus-4-8", // see www.ruapi.ai for available models
  messages: [
    { role: "user", content: "Explain quantum entanglement simply." },
  ],
});

console.log(response.choices[0].message.content);

Example: curl + streaming

curl https://www.ruapi.ai/v1/chat/completions \
  -H "Authorization: Bearer sk-YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-opus-4-8",
    "messages": [{"role": "user", "content": "Write a haiku about code."}],
    "stream": true
  }'

Claude protocol

Use this protocol if your code is built on the Anthropic SDK or you need Claude-specific features (thinking blocks, native tool calls).

Endpoint

POST https://www.ruapi.ai/v1/messages

Compatibility

The request/response format matches Anthropic’s Messages API. Supported:

messages array (native Claude format)
system as a separate field
model — Claude model name or any other (we convert it into the Claude protocol)
max_tokens (required for Claude)
stream: true
tools / tool_choice
thinking for reasoning models

Example: Python (Anthropic SDK)

from anthropic import Anthropic

client = Anthropic(
    api_key="sk-YOUR_KEY",
    base_url="https://www.ruapi.ai",
)

response = client.messages.create(
    model="claude-opus-4-8",  # see www.ruapi.ai for available models
    max_tokens=1024,
    system="You are a technical expert.",
    messages=[
        {"role": "user", "content": "What is the CAP theorem?"},
    ],
)

print(response.content[0].text)
print(f"Used: input={response.usage.input_tokens}, output={response.usage.output_tokens}")

Example: Node.js (Anthropic SDK)

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

const client = new Anthropic({
  apiKey: "sk-YOUR_KEY",
  baseURL: "https://www.ruapi.ai",
});

const response = await client.messages.create({
  model: "claude-opus-4-8", // see www.ruapi.ai for available models
  max_tokens: 1024,
  messages: [
    { role: "user", content: "Explain Rust's borrow checker." },
  ],
});

console.log(response.content[0].text);

Example: curl

curl https://www.ruapi.ai/v1/messages \
  -H "x-api-key: sk-YOUR_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-opus-4-8",
    "max_tokens": 1024,
    "messages": [{"role": "user", "content": "Write a haiku about code."}]
  }'

The Anthropic SDK uses the x-api-key header instead of Authorization: Bearer. RuAPI accepts both on the /v1/messages endpoint.

Which protocol should I pick?

Scenario	Use
Already on OpenAI SDK / LangChain / LlamaIndex	OpenAI protocol
Writing native Anthropic code, need thinking blocks	Claude protocol
Want to call Claude from existing OpenAI code	OpenAI protocol (we convert)
Want to call gpt-5.4 from Anthropic SDK	Claude protocol (we convert)

In every case — same API key, same per-token price, shared balance.

All endpoints

Method	Path	Purpose
POST	`/v1/chat/completions`	OpenAI Chat Completions
POST	`/v1/messages`	Claude Messages
POST	`/v1/embeddings`	Embeddings (OpenAI compatible)
POST	`/v1/images/generations`	Image generation (OpenAI compatible)
POST	`/v1/audio/transcriptions`	Whisper transcription
POST	`/v1/audio/speech`	TTS — text to speech
GET	`/v1/models`	List of available models

The full list with current models lives on the Pricing page at www.ruapi.ai.

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API Reference

OpenAI protocol

Claude protocol

Base URL

OpenAI protocol

Endpoint

Compatibility

Example: Python (OpenAI SDK)

Example: Node.js (OpenAI SDK)

Example: curl + streaming

Claude protocol

Endpoint

Compatibility

Example: Python (Anthropic SDK)

Example: Node.js (Anthropic SDK)

Example: curl

Which protocol should I pick?

All endpoints

OpenAI protocol

Claude protocol

​Base URL

​OpenAI protocol

​Endpoint

​Compatibility

​Example: Python (OpenAI SDK)

​Example: Node.js (OpenAI SDK)

​Example: curl + streaming

​Claude protocol

​Endpoint

​Compatibility

​Example: Python (Anthropic SDK)

​Example: Node.js (Anthropic SDK)

​Example: curl

​Which protocol should I pick?

​All endpoints

Base URL

OpenAI protocol

Endpoint

Compatibility

Example: Python (OpenAI SDK)

Example: Node.js (OpenAI SDK)

Example: curl + streaming

Claude protocol

Endpoint

Compatibility

Example: Python (Anthropic SDK)

Example: Node.js (Anthropic SDK)

Example: curl

Which protocol should I pick?

All endpoints