Claude Sonnet 5.5 is the current Sonnet-class model from Anthropic and a direct upgrade over Claude Sonnet 5, aimed at well-scoped everyday work: building features, fixing bugs, and producing reliable output on agentic coding and enterprise tasks. It pairs a 1M-token context window with 128K max output and accepts text, image, and file input. Reasoning is always on, with five effort levels (low through max, default high) that trade thoroughness against token spend. The effort levels were recalibrated relative to Sonnet 5, so an existing integration should re-tune them rather than carry its old setting over. Native tool calling, structured outputs, and response_format are all supported. It speaks the Anthropic Messages API natively and is also reachable through the OpenAI chat-completions format, making it a drop-in upgrade for existing Claude integrations at the same price as Sonnet 5.
OpenAI-compatible — keep the SDK you already use
https://api.orcarouter.ai/v1https://api.orcarouter.aiimport os
from openai import OpenAI
client = OpenAI(
base_url="https://api.orcarouter.ai/v1",
api_key=os.environ["ORCAROUTER_API_KEY"],
)
response = client.chat.completions.create(
model="anthropic/claude-sonnet-5.5",
messages=[{"role": "user", "content": "Hello"}],
)
print(response.choices[0].message.content)include_reasoningmax_completion_tokensmax_tokensreasoningreasoning_effortresponse_formatstopstructured_outputstemperaturetool_choicetoolsverbosity| Input / 1M tokens | $2.00 |
|---|---|
| Output / 1M tokens | $10.00 |
| Cache read / 1M | $0.200 |
| Cache write / 1M | $2.50 |
| Currency | USD |
Estimate based on list price
Estimate only — actual token counts depend on the provider's tokenizer.
What developers are saying this week
GET /api/public/models/anthropic/claude-sonnet-5.5Open @misc{orcarouter_claude_sonnet_5_5,
title = {Claude Sonnet 5.5 API},
author = {Anthropic},
year = {2026},
howpublished = {OrcaRouter},
url = {https://www.orcarouter.ai/models/anthropic/claude-sonnet-5.5}
}Anthropic. (2026). Claude Sonnet 5.5 API. OrcaRouter. https://www.orcarouter.ai/models/anthropic/claude-sonnet-5.5