The only one million token model available to 20x users (that I have found to work) is claude-sonnet-4-5-20250929[1m] - Can you create Sonnet 4.5 1M somewhere like here?
1. Default (recommended) Opus 4.6 · Most capable for complex work
2. Sonnet Sonnet 4.6 · Best for everyday tasks
3. Haiku Haiku 4.5 · Fastest for quick answers
4. Opus 4.6 Claude Opus 4.6 (February 2026)
5. Opus 4.5 Claude Opus 4.5 (November 2025)
6. Sonnet 4.5 Claude Sonnet 4.5 (September 2025)
7. Sonnet 4.5 1M Claude Sonnet 4.5 (September 2025) <<<
8. Opus 4.1 Claude Opus 4.1 (August 2025)
...
and here, because it doesn't appear to use a model that functions on the 20x sub:
17. Opus Plan Mode 1M Use Opus 4.5 in plan mode, Sonnet 4.5 (1M context) otherwise
The only one million token model available to 20x users (that I have found to work) is
claude-sonnet-4-5-20250929[1m]- Can you create Sonnet 4.5 1M somewhere like here?and here, because it doesn't appear to use a model that functions on the 20x sub: