jev-compaction

1# Choosing turns with Jev, and what actually makes a handoff work
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3Jev cannot write a summary. It can mark each turn of a transcript:
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5- **keep**: carries a decision, a constraint, a preference, unfinished work, or an exact value, path, id, command or error that later work depends on.
6- **summarize**: background whose gist matters. In the digest this is the turn's first 400 characters, nothing more. Jev writes no gist.
7- **drop**: chatter, superseded attempts, repeated output.
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9It judges a long turn on its first 350 and last 350 characters, redacted, 40 turns per request, and sees no other turn while it does.
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11## Read this before you use it for a handoff
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13This skill used to say a handoff written from Jev's digest "stops losing the one line that mattered". We measured that on seven real sessions and 104 recall questions ([scorecard](../../evals/compaction/results/SCORECARD-2026-09-20.md)) and it was wrong:
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15| the writer reads | capsule | recall alone | with one search of the old session |
16|---|---|---|---|
17| Jev's digest | 400 words | 37.5% | 68.3% |
18| the plain last 24,000 characters | 400 words | 48.1% | 68.3% |
19| **the whole dialogue** | **1,200 words** | **58.7%** | **75.0%** |
20| nothing: no handoff at all | | | 56.7% |
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