---
title: "Claude Sonnet 5.5 — API access"
description: "Claude Sonnet 5.5 API pricing: official $2/$10 per 1M tokens, $1/$5 with the flat 50% apiToken.sale discount. Cache reads are $0.20 per 1M."
url: "https://apitoken.sale/models/claude-sonnet-5-5"
language: "en"
---
# Claude Sonnet 5.5

Claude Sonnet 5.5 is Anthropic's September 2026 Sonnet and the default Sonnet in Claude Code, at the same token price as Sonnet 5.

- **Model ID:** `claude-sonnet-5-5`
- **Tier:** Sonnet
- **Context window:** 1M tokens
- **Max output:** 128K tokens
- **Official price (per 1M):** $2 input / $10 output
- **Your price (per 1M):** input $1, output $5 (flat 50% off)
- **Base URL:** `https://router.apitoken.sale` · **Endpoint:** `POST /v1/messages`

## Best for

- Everyday coding and agent loops — the new Sonnet default.
- Agentic workflows where Opus cost is not justified.
- High-volume production API traffic.

## Notes

- Official rates per 1M tokens: $2 input, $0.20 cache read, $2.50 5-minute cache write, $4 1-hour cache write, $10 output — the same card as Sonnet 5.
- Adaptive thinking is on by default. thinking type "disabled" returns 400; send "between_tools" at high effort or below to turn off up-front thinking.
- Forced tool_choice any/tool and a non-default temperature, top_p or top_k return 400.

## Call it

```bash
curl https://router.apitoken.sale/v1/messages \
  -H "x-api-key: $APITOKEN_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{"model": "claude-sonnet-5-5", "max_tokens": 1024, "messages": [{"role": "user", "content": "Hello"}]}'
```

## FAQ

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

Officially $2 per 1M input tokens and $10 per 1M output tokens, the same as Sonnet 5. Cache reads are $0.20, 5-minute cache writes $2.50, and 1-hour cache writes $4 per 1M. apiToken.sale applies the flat 50% discount: $1/$5.

**What is the model ID for Claude Sonnet 5.5?**

claude-sonnet-5-5. Use it unchanged with the Anthropic SDK, Claude Code, Cursor, Cline or any compatible tool pointed at https://router.apitoken.sale.

**Sonnet 5.5 or Sonnet 5?**

Sonnet 5.5 is the newer Sonnet at the same price. Code that disables thinking or forces a tool must change first: send thinking type between_tools instead of disabled, and tool_choice auto instead of any/tool.

---
API reference: https://apitoken.sale/md/docs · All models: https://apitoken.sale/md/models