Anthropic

claude-sonnet-5-5

anthropicmodel ID claude-sonnet-5-5-35%

claude-sonnet-5-5 costs $1.30 per million input tokens and $6.50 per million output tokens through the KoRouter API — 35% below Anthropic's official rate, pay as you go with credits.

  • Context window1M input tokens
  • Input modalitiestext, image, file
  • Output modalitiestext

Call it in one request

curl · claude-sonnet-5-5
curl https://korouter.ai/v1/messages \
  -H "x-api-key: sk-your-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" }]
  }'

claude-sonnet-5-5 is served on the Anthropic Messages API, so Claude Code reaches it by pointing ANTHROPIC_BASE_URL at KoRouter — no wrapper, no proxy config. The same model ID also answers on the OpenAI-compatible endpoint above, which is what Codex, Cline, Continue and Aider use. Setup guides per tool.

Replace sk-your-key with a key from the console. Model IDs are bare names — see the docs.

What a real coding session costs

Per-token price tables mislead for agentic coding. A focused two-hour Claude Code session re-sends its context on every request, so 88% of its tokens are cache reads rather than fresh input — and the cache rate, not the headline input price, decides most of the bill. Priced at claude-sonnet-5-5's live rates, that session costs $1.87 through KoRouter, against $2.88 at Anthropic's official prices.

  • Cache reads · 5M tokens$0.33
  • Fresh input · 250K tokens$0.33
  • Output · 100K tokens$0.65
  • Cache writes · 350K tokens$0.57
  • Session total$1.87

The token mix is a stated assumption, not a measurement — change it and re-price every model in the cost calculator, or read the full worked example in what a real Claude Code session costs. Prices come from the live billing catalog.

The same session elsewhere

The same reference session, priced at each model's live KoRouter rates — the nearest options on either side of claude-sonnet-5-5.

Supported parameters

max_tokensmax_completion_tokensreasoningreasoning_effortinclude_reasoningtoolstool_choiceresponse_formatstructured_outputsweb_search_options

More models

claude-opus-5-5claude-fable-5.1claude-fable-5claude-haiku-4-5claude-opus-4-6claude-opus-4-7claude-opus-4-8claude-opus-5

Prices use the live billing catalog · live availability · all models