Claude Opus 5.5

Anthropic's flagship model for deep reasoning, complex agentic coding, and long-horizon enterprise work.

FlagshipDeep ReasoningPrompt Caching

Context Window

claude-opus-5-5

Max Output

1M tokens

Input

$3.6$4

10% off

1M tokens

Output

$18$20

10% off

1M tokens

Model Codeclaude-opus-5-5

Playground

Model Code

claude-opus-5-5

Enter your prompt here...

Output

No output yet

Pricing

Plan	Context Window	Max Output	Input	Output	Cache Write	Cache Read
claude-opus-5-5	-	-	$3.6$410% off 1M tokens	$18$2010% off 1M tokens	$4.5$510% off 1M tokens	$0.18$0.210% off 1M tokens

Cache Write 1h · $7.2 · 1M tokens

Cache read or cached input pricing applies to reused prompt tokens.

README

Claude Opus 5.5 is Anthropic's flagship model for complex agentic coding and enterprise work, with deep reasoning, long-horizon execution, and $4/$20 pricing.

Claude Opus 5.5 is built for demanding agentic and long-horizon work, including multi-file software engineering, complex refactors, code review, and enterprise workflows that require sustained reasoning across many steps.
The Opus tier pairs strong deep reasoning and long-horizon execution with prompt caching for lower repeated-context costs.
ReachAPI exposes the model through the `claude-opus-5-5` model code over the Claude Messages protocol.

API

Use the API docs for request format, parameters, and integration details.

Anthropic's flagship model for deep reasoning, complex agentic coding, and long-horizon enterprise work.

Model Code

claude-opus-5-5

View API Docs

API

Endpoint

POST /v1/messages

Authentication

Authorization: Bearer YOUR_REACH_API_KEY
anthropic-version: 2023-06-01
Content-Type: application/json

Example

curl -X POST "https://direct.reachapi.ai/v1/messages" \
  -H "Authorization: Bearer YOUR_REACH_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "YOUR_MODEL_ID",
    "messages": [
      {
        "role": "user",
        "content": "Introduce ReachAPI in one sentence."
      }
    ],
    "max_tokens": 512,
    "temperature": 0.2
  }'

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