> ## Documentation Index
> Fetch the complete documentation index at: https://docs.unifically.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Claude Haiku 5.5

> Anthropic's Claude Haiku 5.5 language model. See supported inputs, parameters, pricing, response fields, and API examples.

Claude Haiku 5.5 is Anthropic's small, fast model from the Claude 5.5 family, released October 7, 2026, for high-volume, latency-sensitive work such as classification, extraction, routing and sub-agent tasks. It takes text and image input, outputs text, and carries a 1M token context window with up to 128k output tokens. It uses adaptive thinking steered by effort, which defaults to `medium`. Leave `temperature`, `top_p` and `top_k` unset; non-default values return a 400 error.

Pricing is tiered by prompt length: when a request's prompt (input plus cached tokens) is over 100,000 tokens, every token in that request bills at the higher tier. Both tiers are listed on the [pricing page](https://unifically.com/pricing).

Try it in the browser: [Claude Haiku 5.5 API playground](https://unifically.com/models/claude-haiku-5.5).

## Model

```
anthropic/claude-haiku-5-5
```

| | |
| - | - |
| **Provider** | Anthropic |
| **Name** | Claude Haiku 5.5 |

## Supported Endpoints

All three API formats are supported:

* [Chat Completions](/api-reference/v1-chat-completions) — `POST /v1/chat/completions`
* [Responses](/api-reference/v1-responses) — `POST /v1/responses`
* [Messages](/api-reference/v1-messages) — `POST /v1/messages`

## Example

```bash theme={null}
curl -X POST https://api.unifically.com/v1/messages \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "anthropic/claude-haiku-5-5",
    "max_tokens": 1024,
    "messages": [
      {"role": "user", "content": "Classify this ticket as billing, bug, or feature request and return JSON: \"I was charged twice for my top-up.\""}
    ]
  }'
```

<Note>
  **Volume discounts** are available for almost all models. Reach out at [contact@unifically.com](mailto:contact@unifically.com) to discuss custom pricing.
</Note>


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.