Opus 4.6 adds a larger context option and effort controls

Anthropic released Claude Opus 4.6 on 5 February for Claude, its API and major cloud platforms. Its announcement introduced a one-million-token context window in beta on the Claude developer platform, alongside controls for how much reasoning effort a task receives.

The company also added beta context compaction, which summarises older material as a conversation approaches its limit. These features address different problems: a larger window accommodates more material at once, while compaction helps an agent continue through a longer sequence of work.

Base pricing remained $5 per million input tokens and $25 per million output tokens. Prompts exceeding 200,000 tokens carried premium rates of $10 and $37.50 respectively. Anthropic reported improvements in coding, research and document work; those are vendor evaluations. The access and pricing changes gave developers concrete choices about how to balance context, effort and running costs. A team handling large document collections therefore needs to price the chosen prompt size.