Claude Opus 4.8: model ids, price and cutoff

How to call it

7 ways to use Claude Opus 4.8, with the model id each provider expects.

Providers, model ids, endpoints and docs for Claude Opus 4.8
Provider	Model id	Endpoint	Docs
Anthropic API (Claude API)	`claude-opus-4-8`	`https://api.anthropic.com/v1/messages`	platform.claude.com
AWS Bedrock (Messages API / Mantle)	`anthropic.claude-opus-4-8`		platform.claude.com
Google Cloud Vertex AI	`claude-opus-4-8`		platform.claude.com
Microsoft Foundry (Azure)	`claude-opus-4-8`		platform.claude.com
Claude Platform on AWS	`claude-opus-4-8`		platform.claude.com
OpenRouter	`anthropic/claude-opus-4.8`		openrouter.ai
Web app			claude.ai

Pricing

Prices for Claude Opus 4.8
Input	$5 per 1M tokens
Output	$25 per 1M tokens
Cache read	$0.50 per 1M tokens

As published: “per 1M tokens (USD); Batch API 50% off”.

Source: platform.claude.com, checked 29 September 2026.

Specs

Input: Text, images and PDF
Output: Text
Context window: 1,000,000 tokens
Max output: 128,000 tokens
Open weights: No
Licence: Proprietary
Training cutoff: January 2026
Released: 28 May 2026
Status: Legacy
Type: Reasoning model

What stands out

What its maker marketed at launch, and what people found later, each with its source.

Code honesty

About 4x less likely than Opus 4.7 to let flaws in its own code pass without comment.

Source: anthropic.com
Browser agents

Scored 84% on Online-Mind2Web, ahead of Opus 4.7 and GPT-5.5.

Source: anthropic.com
Legal agent benchmark

First

Anthropic says it was the first model to exceed 10% on the Legal Agent Benchmark all-pass standard.

Source: anthropic.com
Cheaper fast mode

Fast mode runs up to 2.5x faster, at a lower premium than earlier fast mode.

Source: anthropic.com

Four assistants, one scale

Claude Opus 4.8 is added as a fifth row. Each row runs from what the model knows (graphite) through the months between its cutoff and its launch (hatched) to today (pink).

GPT-6 Astra 271 at launch, 1,863 today
Claude Opus 5.5 372 at launch, 1,795 today
Gemini 4 Hydrogen 1,863 at launch, 1,889 today
Grok 4.7 387 at launch, 1,829 today
Claude Opus 4.8 110 at launch, 1,945 today

Show as a table

Model	Cutoff	Released	Missing at launch	Missing today
GPT-6 Astra	April 2026	3 September 2026	271	1,863
Claude Opus 5.5	June 2026	22 September 2026	372	1,795
Gemini 4 Hydrogen	March 2026	12 November 2026	1,863	1,889
Grok 4.7	May 2026	21 September 2026	387	1,829
Claude Opus 4.8	January 2026	28 May 2026	110	1,945

Notes

Last Opus 4.x. Adaptive thinking only (omit thinking = no thinking); sampling params and budget_tokens removed. Fast mode $10/$50 (Claude API only). Retirement not sooner than 2027-05-28.

curl https://api.anthropic.com/v1/messages \
 -H "x-api-key: $ANTHROPIC_API_KEY" -H "anthropic-version: 2023-06-01" -H "content-type: application/json" \
 -d '{"model":"claude-opus-4-8","max_tokens":16000,"messages":[{"role":"user","content":"Hello"}]}'

Sources: