Anthropic: Claude Opus 4.8

anthropic/claude-opus-4.8 · AnthropicNot yet established

Declared family: Claude
Evidence confidence: Unknown
Declared tokenizer tag: Claude
Entered catalogue: 27 May 2026
Last tested: Not yet measured
Measurement: Awaiting measurement

Evidence stack

Signals of different kinds, weighed together

Signal	Result	Reference
Tokenizer signature	Not measured	–
API surface	Identical contract to 2 other entries	api_e9541183
Context and output	1,000,000 context · 128,000 max output	declared
Reasoning contract	Optional · efforts max, xhigh, high, medium, low · default high	declared
Serving providers observed	None recorded yet	–

Declared record

What the catalogue claims about this model

Claude Opus 4.8 is Anthropic's most capable generally available model in the Opus family. It supports text, image, and file inputs with text output, with reasoning support and a 1M-token...

Modalities: text+image+file->text
Declared tokenizer: Claude
Prompt price: $5.00 / M tokens
Completion price: $25.0 / M tokens

Supported parameters

include_reasoningmax_completion_tokensmax_tokensreasoningreasoning_effortresponse_formatstopstructured_outputstemperaturetool_choicetoolsverbosity

defaults: {}

Catalogue entry

History

Every observation, kept as taken

27 May 2026Enters the OpenRouter catalogue declared as Claude.

Cite this page as the evidence record for Anthropic: Claude Opus 4.8: the URL is stable, measurements are dated, and revisions append to the history above. Method: tokenizer fingerprinting, v1, 50 strings. The raw data behind every figure is on the data page.