Claude Opus 4.8

anthropic/claude-opus-4.8

A chat model with a 1M-token context window, at $5.25 per million input tokens and $26.25 per million output tokens.

Details

Maker: anthropic
Kind: Chat
Context window: 1,000,000 tokens
Max output: 128,000 tokens
Input: $5.25 per million tokens
Cached input: $0.525 per million tokens, 90% off
Cache write: $6.5625 per million tokens
Output: $26.25 per million tokens
Capabilities: Reasoning, tool use, vision, file input, web search, fast
Takes: Text, image, pdf
Returns: Text
Zero data retention: Yes, on every provider
No training on requests: Yes, on every provider
Released: 2026-05-28
Newer model: anthropic/claude-haiku-5.5Released later by the same maker, costs no more, and lists the same capabilities. Compare the two

Description

Opus 4.8 is a focused upgrade to Opus 4.7 and is Anthropic's best generally available model for coding, agentic tasks, and enterprise workflows. It builds on the strengths of previous Opus models with stronger performance on complex, multi-step coding tasks. Anthropic recommends using it on long-horizon coding and agentic tasks. It is also stronger on professional work, including document drafting, data analysis, and presentations.

Call it

curl

curl https://phantom.codes/v1/chat/completions \
  -H "Authorization: Bearer $PHANTOM_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-opus-4.8",
    "messages": [
      {"role": "user", "content": "Hello"}
    ]
  }'

Set PHANTOM_KEY to your key. Any OpenAI client works with the base URL https://phantom.codes/v1.

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