01
When an agent is blocked and told why, does it correct itself?
Yes, 11 times out of 11
Claude Code and Codex, blocked from a protected file with a concrete alternative named.
Evidence
Every claim here was measured first.
trackline's design rests on a few claims that would be expensive to get wrong. Each was measured before it was built on. Where a result has limits, the write-up names them next to the number.
Read the write-up →
02
What does a check before every action cost?
About 14 ms, in Go
88 ms in Node against 6.5 ms for a bare Go start, across 265 tool calls; the full hook runs in 11 to 14 ms.
03
Can alignment be checked from production traces?
Only with content capture on, and it survives redaction
The official OpenTelemetry instrumentation, captured under four configurations.
04
Does it cry wolf on ordinary work?
0 false alarms in 23 actions
Ordinary sessions replayed through every check, and real usage that found what scripts missed.
05
Can a model tell on-task work from drift?
8 of 8 on a calibration set
Superseded by experiment 6, which measured it properly.
06
Does the judge earn its place, on real agents and held-out drift?
60 of 60 held-out drifts, against 2 for the rules
Three agents, labels committed before any session ran, a judge from a different model family.
07
Does the same engine watch a deployed agent?
Yes, with zero lines of the core changed
45 pre-registered conversations sent by the real OpenTelemetry libraries: every labelled problem caught, none of 29 on-task flagged.