Module token_estimator 

Fast heuristic token estimation for context window management.

Uses character-based heuristics rather than a full tokenizer to avoid heavy dependencies. Accuracy is ±20% which is sufficient for deciding when to truncate or compact conversation history.

Functions

estimate_message_tokens

Estimate token count for a single message.

estimate_messages_tokens

Estimate total token count for a slice of messages.

estimate_tokens

Estimate token count for a text string.

estimate_tool_tokens

Estimate total token count for tool descriptors.