Retained code rate
The share of AI-written characters or lines still present in the file after a period (e.g. 30 seconds, or at commit).
Retention answers what acceptance rate cannot: did the suggestion survive? Vendors report retained-character rates because a suggestion that is accepted then deleted cost time rather than saving it. Retention is also the metric GitClear-style analyses invert: they measure the churn of lines revised within two weeks of being written, which rose alongside AI adoption.