Claude Opus 5

anthropic/claude-opus-5 · AnthropicNot yet established

Declared family: Claude
Evidence confidence: Unknown
Declared tokenizer tag: Claude
Entered catalogue: 24 July 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 5 is Anthropic’s flagship model for demanding reasoning, coding, and long-horizon agentic work. It is particularly strong at end-to-end software tasks, code review and bug finding, visual analysis...

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

24 July 2026Enters the OpenRouter catalogue declared as Claude.

Cite this page as the evidence record for Claude Opus 5: 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.