Claude Sonnet 5.5 Chat Completion

Call Claude Sonnet 5.5 through PixMind with token pricing, cache rates, and documented request parameters.

Use Claude Sonnet 5.5 for everyday coding, structured writing, and long-document synthesis.

Claude Sonnet 5.5 through PixMind's OpenAI-compatible chat completions endpoint.

Provider

Anthropic

Model ID

claude-sonnet-5-5

Endpoint

POST /api-platform/v1/chat/completions

Open model playground Create API key

Authentication

Base URL: https://aihub-admin.aimix.pro. Send Authorization: Bearer <PIXMIND_API_KEY> on both creation and polling requests, and Content-Type: application/json when submitting JSON. Keep your key in a server environment variable.

Model notes

Keep the API key on your server and use streaming when the client needs incremental output.
Claude 5.5, 5, and 4.8 use adaptive thinking. Set output_config.effort to low, medium, high, xhigh, or max; reasoning_effort is accepted as an OpenAI-compatible alias.
Changing thinking or effort starts a new prompt-cache prefix.
Cache-read tokens and cache-write tokens with 5-minute or 1-hour retention are reported separately.
The current route supports 1,000,000 input tokens and 128,000 output tokens.

Request parameters

Parameter	Type	Required	Description
`model`	string	Yes	Stable PixMind model ID. Use `claude-sonnet-5-5`. Allowed values: `claude-sonnet-5-5`
`messages`	array	Yes	OpenAI-compatible chat messages. Gemini user content may be a string or an array of text, image_url, and video_url blocks.
`max_tokens`	integer	No	Maximum completion tokens; send a positive integer up to 128000. Playground default: `4096`
`thinking`	object	No	Claude thinking mode. Use {"type":"adaptive"}. Default: `{"type":"adaptive"}`
`output_config`	object	No	Thinking depth, for example {"effort":"high"}. Default: `{"effort":"high"}`
`stream`	boolean	No	Return tokens incrementally when enabled. Allowed values: `true`, `false` Default: `false`

Request example

cURL

curl --request POST 'https://aihub-admin.aimix.pro/api-platform/v1/chat/completions' \
  -H "Authorization: Bearer $PIXMIND_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "claude-sonnet-5-5",
  "messages": [
    {
      "role": "user",
      "content": "Draft three launch concepts for this product."
    }
  ],
  "thinking": {
    "type": "adaptive"
  },
  "output_config": {
    "effort": "high"
  },
  "stream": false
}'

JavaScript

// Node.js 20+. Keep the API key on your server.
const apiKey = process.env.PIXMIND_API_KEY;
if (!apiKey) throw new Error("PIXMIND_API_KEY is required");

const response = await fetch("https://aihub-admin.aimix.pro/api-platform/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${apiKey}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
  "model": "claude-sonnet-5-5",
  "messages": [
    {
      "role": "user",
      "content": "Draft three launch concepts for this product."
    }
  ],
  "thinking": {
    "type": "adaptive"
  },
  "output_config": {
    "effort": "high"
  },
  "stream": false
}),
  signal: AbortSignal.timeout(30_000)
});

const task = await response.json();
if (!response.ok) {
  throw new Error(task.message ?? task.error?.message ?? `HTTP ${response.status}`);
}
console.log(task);

Response example

Non-streaming chat completions return choices directly. With stream: true, consume the SSE stream instead.

200 OK

{
  "id": "chatcmpl_example",
  "object": "chat.completion",
  "model": "claude-sonnet-5-5",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello!"
      },
      "finish_reason": "stop"
    }
  ]
}