# Claude Sonnet 5.5 MCP and API - Chat model by Anthropic | FlyMy.AI

> Anthropic Claude Sonnet 5.5 balances speed and capability for everyday coding, agents and business work, with image input and a 1M-token context.

Page: https://flymy.ai/mcp/models/claude-sonnet-5-5/

MCP / Models / Language models

# Claude Sonnet 5.5 MCP: coding and agents with no API key

Anthropic Claude Sonnet 5.5 balances speed and capability for everyday coding, agents and business work, with image input and a 1M-token context. Run it from Claude Code, Codex, Cursor or any MCP client through one FlyMy.AI MCP, or call its API.

[Use Claude Sonnet 5.5](https://flymy.ai/mcp/models/claude-sonnet-5-5/#start) [Inputs and price](https://flymy.ai/mcp/models/claude-sonnet-5-5/#inputs)

No API key, $2.00 / $10.00 per 1M tokens, Chat model, Anthropic, Commercial use

$ YOUR NEXT RUN

Claude Code, Codex, Cursor, Any agent

## Use Claude Sonnet 5.5 in your assistant

Paste this prompt into Claude Code, Codex, Cursor or any agent. It reads the guide and helps you connect.

```
Read https://flymy.ai/skill.md and https://flymy.ai/mcp/models/claude-sonnet-5-5.md. Help me connect the FlyMy.AI MCP to this assistant, then run Claude Sonnet 5.5 (flymyai/claude-sonnet-5-5) for this task: Ask Claude Sonnet 5.5: write unit tests for this Python module.
```

[Open FlyMy.AI](https://app.flymy.ai/new-agent) [Download brief](https://flymy.ai/mcp/models/claude-sonnet-5-5.md)

## What Claude Sonnet 5.5 does

Send a prompt, or a chat history in messages with images as image_url parts, and get a text answer of up to 128K tokens from a 1M-token context. reasoning_effort is low, medium, high, xhigh or max (high by default); system_prompt and max_tokens work as usual, and private_mode keeps the prompt and answer out of FlyMy.AI storage. Your FlyMy.AI key also works on the OpenAI-compatible Chat Completions endpoint and on Anthropic's Messages API at the model's FlyMy.AI address, so the official Anthropic SDK runs once you change its base URL; PDFs, prompt caching and reasoning_effort need the Messages API. Billing follows the tokens Anthropic reports, at Anthropic's own price. Tools Anthropic runs itself, such as web search, are not offered.

Guide: [LLM API: GPT, Claude and Gemini with One Key](https://flymy.ai/blog/llm-api-gpt-claude-gemini/)

## Claude Sonnet 5.5 inputs

Every input of `flymyai/claude-sonnet-5-5` as its live schema lists them. Returns `output` (string), `finish_reason` (string), `stream_details` (string).

| Input | Type, values and default |
|---|---|
| [#](https://flymy.ai/mcp/models/claude-sonnet-5-5/#input-prompt) `prompt` | string required What to ask Claude Sonnet 5.5 |
| [#](https://flymy.ai/mcp/models/claude-sonnet-5-5/#input-messages) `messages` | string optional Chat history as a JSON array of {role, content}; used instead of the prompt |
| [#](https://flymy.ai/mcp/models/claude-sonnet-5-5/#input-system_prompt) `system_prompt` | string optional Instructions for the whole chat |
| [#](https://flymy.ai/mcp/models/claude-sonnet-5-5/#input-reasoning_effort) `reasoning_effort` | string optional Allowed: low, medium, high, xhigh, max Default: `high` How much effort Claude Sonnet 5.5 puts into the answer, reasoning included |
| [#](https://flymy.ai/mcp/models/claude-sonnet-5-5/#input-max_tokens) `max_tokens` | integer optional Allowed: 1 to 128000 Most tokens to generate, reasoning included |
| [#](https://flymy.ai/mcp/models/claude-sonnet-5-5/#input-private_mode) `private_mode` | boolean optional Default: `false` Keep the prompt and the answer out of FlyMyAI storage and logs (synchronous requests only) |

## Ask your agent

Requests to paste as they are, once the FlyMy.AI MCP is connected.

**“Ask Claude Sonnet 5.5: write unit tests for this Python module.”** runs `flymyai/claude-sonnet-5-5`

**“Compare these two product specs in a table with Claude Sonnet 5.5.”** runs `flymyai/claude-sonnet-5-5`

**“With Claude Sonnet 5.5, rewrite this landing page paragraph to be shorter and clearer.”** runs `flymyai/claude-sonnet-5-5`

## Claude Sonnet 5.5 price

$2.00 per 1M input tokens, $10.00 per 1M output tokens, cached input $0.10 per 1M, cache writes $2.50 per 1M ($4.00 kept longer). Cached input is $0.10 per 1M tokens. Billed to your FlyMy.AI balance; no seats, no subscription and no minimum.

[See usage pricing →](https://flymy.ai/pricing/)

## Call Claude Sonnet 5.5 from code

The same model, from an agent or from your own code. Keys stay in your FlyMy.AI account.

### From an agent, through the MCP

The agent calls `get_model_schema`, then `run_model` with:

```
{
  "endpoint_id": "flymyai/claude-sonnet-5-5",
  "input": {
    "prompt": "Explain in two sentences what an MCP server is."
  }
}
```

### From your code, over HTTP

Form fields, not JSON; files go as uploads or public URLs. Text models answer on the streaming route.

```
curl -X POST https://api.flymy.ai/api/v1/flymyai/claude-sonnet-5-5/predict/stream/ \
  -H "X-API-KEY: $FLYMYAI_API_KEY" \
  -F 'prompt=Explain in two sentences what an MCP server is.'
```

### With the OpenAI SDK

Claude Sonnet 5.5 also answers the OpenAI Chat Completions protocol.

```
from openai import OpenAI

client = OpenAI(base_url="https://api.flymy.ai/api/v1/flymyai/claude-sonnet-5-5/openai/v1", api_key="YOUR_FLYMYAI_KEY")
reply = client.chat.completions.create(
    model="flymyai/claude-sonnet-5-5",
    messages=[{"role": "user", "content": "Explain in two sentences what an MCP server is."}],
)
print(reply.choices[0].message.content)
```

## Questions about Claude Sonnet 5.5

**Do I need a Anthropic API key for Claude Sonnet 5.5?**

No. Claude Sonnet 5.5 runs on FlyMy.AI's account, so you need no Anthropic key or plan: sign in to FlyMy.AI once and each run is billed to your FlyMy.AI balance.

**How much does Claude Sonnet 5.5 cost?**

$2.00 per 1M input tokens, $10.00 per 1M output tokens, cached input $0.10 per 1M, cache writes $2.50 per 1M ($4.00 kept longer). There is no subscription or minimum; the price comes from FlyMy.AI billing and was checked on 2026-11-12.

**How do I use Claude Sonnet 5.5 in Claude Code, Codex or Cursor?**

Add the FlyMy.AI MCP with one command and sign in, then ask in plain words, for example: "Ask Claude Sonnet 5.5: write unit tests for this Python module." Your agent reads the inputs with get_model_schema and runs flymyai/claude-sonnet-5-5 with run_model.

**What does Claude Sonnet 5.5 need as input?**

Claude Sonnet 5.5 requires prompt; it also takes 5 optional inputs, each listed on this page with its allowed values and default.

**Can I call Claude Sonnet 5.5 from my own code?**

Yes. Send form fields to https://api.flymy.ai/api/v1/flymyai/claude-sonnet-5-5/predict/stream/ with your FlyMy.AI API key in the X-API-KEY header; it also answers the OpenAI Chat Completions protocol at https://api.flymy.ai/api/v1/flymyai/claude-sonnet-5-5/openai/v1.

## More language models models

Chat and reasoning models for code, documents and agents, plus typed decisions for routing and triage.

### Claude Fable 5.2

Anthropic's top Claude, above Opus, for the hardest reasoning and long agent runs.

Chat model / $8.00 / $40.00 per 1M tokens

Link: https://flymy.ai/mcp/models/claude-fable-5-2/

### Claude Haiku 5.5

The lowest-priced current Claude, for quick, high-volume work with a 1M-token window.

Chat model / $0.10 / $0.50 per 1M tokens

Link: https://flymy.ai/mcp/models/claude-haiku-5-5/

### Claude Opus 5.5

The current Claude Opus for complex code, agents and analysis, with reasoning up to max.

Chat model / $4.00 / $20.00 per 1M tokens

Link: https://flymy.ai/mcp/models/claude-opus-5-5/

### Gemini 3.5 Flash-Lite

The current low-cost Gemini for high-volume work, with thinking from minimal up.

Chat model / $0.30 / $2.50 per 1M tokens

Link: https://flymy.ai/mcp/models/gemini-3-5-flash-lite/

### Gemini 3.8 Flash

Google's current Flash model, its suggested start for everyday apps and agents.

Chat model / $0.75 / $3.75 per 1M tokens

Link: https://flymy.ai/mcp/models/gemini-3-8-flash/

### Gemini 4 Argon

The efficient Gemini 4: quicker answers and fewer tokens per turn than Carbon.

Chat model / $2.00 / $10.00 per 1M tokens

Link: https://flymy.ai/mcp/models/gemini-4-argon/

## Go to the source

[Claude Sonnet 5.5 in the playground →](https://app.flymy.ai/models/flymyai/claude-sonnet-5-5), [Claude Sonnet 5.5 guide in the docs →](https://docs.flymy.ai/guides/use-llms), [Model endpoints in the docs →](https://docs.flymy.ai/api/models-endpoints), [Every model on FlyMy.AI →](https://flymy.ai/mcp/models/), [Every MCP in the catalog →](https://flymy.ai/mcp/#catalog), [Usage pricing →](https://flymy.ai/pricing/)

From the FlyMy.AI model catalog of 2026-11-12: inputs from the model's live schema, prices from FlyMy.AI billing. Requests are examples to paste, not recorded runs.

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For agents: the FlyMyAI operating guide (sign up, connect, run models, tools and agents) is https://flymy.ai/skill.md, and https://flymy.ai/llms.txt lists the other pages and the documentation.