A delegate_task child inherits the compression threshold as a RATIO of the
model window. On a 1M-window model at the run's configured 0.85 that is an
850K-token trigger: in the 1,393-agent refactor run 1,373 of 1,375 children
never compressed once, 62% of all API calls carried >150K of context, and the
calls above 200K carried ~$10.9k of the $19.3k bill (58% of it cache WRITES,
i.e. re-sending a 300-800K prefix on every call). A sawtooth replay of the
logged calls with a 200K cap / 65K floor cuts context spend by ~49% (~$7k).
Children are brief-driven and disposable; they re-read their brief and the
files they touch, so a large window buys them little. New
delegation.compression_threshold_tokens (default 200000) is applied to the
child's ContextCompressor right after construction as the lower of it and
any global compression.threshold_tokens; the parent's own trigger is
untouched. 0 disables the subagent-specific cap. The compressor applies
threshold_tokens_cap on first window resolution, so this is byte-equivalent
to the user having set compression.threshold_tokens for the child.
Live through the real spawn path (_build_child_agent, real imports, temp
HERMES_HOME, 1M-window model): main child trigger 500,000 / branch 200,000;
parent 500,000 on both.
Tests (3): default caps a 1M child at 200K; the cap is the lower of the
delegation and global values and never raises a small-window child's
trigger; 0 disables and an already-resolved trigger is re-clamped.
Docs: delegation.md, configuration.md.
Teknium
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