altrouter.ai
Models/Anthropic/Claude Opus 4.6
CL

Anthropic: Claude Opus 4.6

Textclaude-opus-4-6

Claude Opus 4.6: top-tier reasoning and autonomous coding.

API docs
Playgroundclaude-opus-4-6
Max tokens
Reasoning
Throughput138 tok/s
24hnow
Latency1.01 s
24hnow
Specifications
Authoranthropic
ModalityText
Context200K tokens
Input$3.99/M tokens$5.00/M tokens
Output$20.00/M tokens$25.00/M tokens
Savings20%
Capabilitiesreasoning, tool calling, image input
Quick start
from openai import OpenAI

client = OpenAI(
    base_url="https://api.altrouter.ai/v1",
    api_key="ar-...",
)

resp = client.chat.completions.create(
    model="claude-opus-4-6",
    messages=[{"role": "user", "content": "Hello!"}],
)
print(resp.choices[0].message.content)

Same OpenAI-compatible endpoint — just swap base_url and key.

API

OpenAI-compatible chat completions endpoint, with SSE streaming.

POST/v1/chat/completions
Body parameters
modelstringrequired"claude-opus-4-6"
The model id.
messagesarrayrequired
The conversation: [{ role, content }].
streambooleandefault false
Stream the response over SSE.
max_tokensnumber1–8192default 4096
Maximum tokens to generate.
reasoning_effortbooleandefault false
Thinking budget for reasoning models.

Structured fields (tools, response_format, stop and more) are in the full parameter reference.

Response
idstring
Completion id.
choicesarray
Completions. Each: index, message { role, content, reasoning_content, tool_calls }, finish_reason.
usageobject
Tokens: prompt_tokens, completion_tokens, total_tokens.
Example
cURLPythonJSON
curl https://api.altrouter.ai/v1/chat/completions \
  -H "Authorization: Bearer ar-..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "claude-opus-4-6",
  "messages": [
    {
      "role": "user",
      "content": "Hello!"
    }
  ]
}'
Errors
400Invalid request.
401Missing or invalid API key.
402Insufficient credits, or the key’s spending cap is exhausted.
404Model not found.
429Rate limit exceeded.
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