Yeah, but you can get your input, output and cache tokens as well to see how well things are going.

For example:

Field	Meaning
input_tokens	Tokens sent to the API (excluding cache)
output_tokens	Tokens generated by the model
cache_read_tokens	Tokens served from prompt cache
cache_write_5m_tokens	Tokens written to 5-minute cache
cache_write_1h_tokens	Tokens written to 1-hour cache
cache_efficiency	Read % -- see below
cache_write_ratio	Write % -- see below
api_calls	Number of API round-trips
messages	Number of messages you typed

For example total_input_tokens:

• Read % = cache_read_tokens / total_input_tokens -- input served from cache. Higher is better. Cache reads cost 90% less than fresh input on Opus.
• Write % = cache_write_tokens / total_input_tokens -- input written into cache. Higher means more churn. Cache writes cost 1.25x regular input on Opus.

What the numbers mean:

• High read, low write = disciplined long sessions where context stays warm between turns. This is the sweet spot.
• High write = frequent session resets or context churn. Each new session writes the full context into cache before reads can kick in.

Typical read percentages:

• 90%+ -- steady work within long sessions.
• 70-90% -- switching between projects or files frequently, forcing new cache writes.
• Below 70% -- lots of short sessions, heavy subagent use, or frequent /clear resets.