Module context 

Context window management defaults Based on Anthropic context window documentation: https://docs.anthropic.com/en/docs/build-with-claude/context-windows

Constants

BETA_CONTEXT_1M

Beta header for 1M token context window Include in requests to enable extended context for Sonnet 4/4.5

CODE_HEAD_RATIO_PERCENT

Head ratio percentage for code files (legacy, kept for compatibility)

CONTEXT_AWARE_MODELS

Models that support context awareness (budget tracking in prompts) Context awareness: model tracks remaining token budget throughout conversation Currently: Claude Sonnet 4.5, Claude Haiku 4.5

DEFAULT_THINKING_BUDGET

Default thinking budget for production use

ENTERPRISE_CONTEXT_WINDOW

Claude.ai Enterprise context window (500K tokens)

EXTENDED_CONTEXT_ELIGIBLE_MODELS

Models eligible for 1M context window (beta) Requires usage tier 4 or custom rate limits

EXTENDED_CONTEXT_WINDOW

Extended context window size (1M tokens) - beta feature Available for Claude Sonnet 4, Sonnet 4.5 in usage tier 4 Requires beta header: “context-1m-2025-08-07”

LOG_HEAD_RATIO_PERCENT

Head ratio percentage for log files (legacy, kept for compatibility)

MIN_THINKING_BUDGET

Minimum budget tokens for extended thinking (Anthropic requirement)

RECOMMENDED_THINKING_BUDGET

Recommended budget tokens for complex reasoning tasks

STANDARD_CONTEXT_WINDOW

Standard context window size (200K tokens) - default for most models

TOKEN_BUDGET_CRITICAL_THRESHOLD

Critical threshold - immediate action required At 90% usage: Force context handoff or summary

TOKEN_BUDGET_HIGH_THRESHOLD

Second warning threshold - active context management needed At 85% usage: Actively summarize and persist state

TOKEN_BUDGET_WARNING_THRESHOLD

First warning threshold - start preparing for context handoff At 70% usage: Consider updating key artifacts to persist context

Functions

supports_context_awareness

Check if a model supports context awareness

supports_extended_context

Check if a model is eligible for 1M context window