News for hackers. Stuff that matters.

A comment on Claude Sonnet 4 now supports 1M tokens of context. Parent comment

Re:Claude Sonnet 4 now supports 1M tokens of context by falcor84 on Tuesday August 12, 2025 @04:06PM (#44881218)
Have you tested it? I see that this env var isn't specified in their docs

https://docs.anthropic.com/en/docs/claude-code/settings#envi...

[ Parent | on HN ]
Re:Claude Sonnet 4 now supports 1M tokens of context by bazhand on Tuesday August 12, 2025 @05:56PM (#44882247) 

    Add these settings to your `.claude/settings.json`:

     ```json
     {
       "env": {
         "ANTHROPIC_CUSTOM_HEADERS": {"anthropic-beta":
     "context-1m-2025-08-07"},
         "ANTHROPIC_MODEL": "claude-sonnet-4-20250514",
         "CLAUDE_CODE_MAX_OUTPUT_TOKENS": 8192
       }
     }
     ```
[ Parent | on HN ]
Re:Claude Sonnet 4 now supports 1M tokens of context by varyherb on Tuesday August 12, 2025 @09:14PM (#44883632)
Yup! Claude Code has a lot of undocumented configuration. Once I saw the beta header value in their docs [1], I tried to see in their source code if there was anyway to specify this flag via env var config. Their source code is already on your computer, just gotta dig through the minified JS :) Try:

`cat $(which claude) | grep ANTHROPIC_BETAS`

Sibling comment's approach with the other (documented) env var works too.

[1] https://docs.anthropic.com/en/docs/build-with-claude/context...

[ Parent | on HN ]