Files
deepseek-harness/packages/compact
Yichen Jiang 765052a7d1 fix(agent-loop): compose the session prefix before pre-step; hand it to the pressure gate
ds-review-bot critical (follow-up): on the first step of a resumed or
seeded/forked instance, auto-compaction ran before runStep composed
this instance's prefix, so the gate read the PREVIOUS instance's logged
prefix from the header fold — a contributor that grew across
resume/fork (skills added, AGENTS.md grown: exactly the
environment-dependent case) could under-gate and ship an over-window
first request.

The loop now composes agent/session-prefix before the instance's first
agent/pre-step (still once per instance; runStep just reads the cache),
and agent/pre-step carries the composed prefix to its listeners.
CompactService.compactIfNeeded gains the sessionPrefix parameter;
BasicCompactService.estimatePressure gates on the handed value — the
header-fold read is gone, so the estimate is exact at every step
including a resumed/forked instance's first. Composition moving before
the boundary snapshot also means a composing listener's session append
now joins the CURRENT request (documented on the seam).

New coverage: composition precedes pre-step and the seam receives the
composed prefix; cancel and disposal landing inside the composition
window drop the step cleanly; the compact gate test hands the prefix
directly.
2026-07-08 20:30:10 +08:00
..

compact/ — compaction capability family

A three-package capability seam (see capability seams): an abstract compaction interface, a backend that summarizes, and the model-facing tool that consumes it. The interface and a first backend (compact-basic/) exist; the consumer tool is deferred. All product packages.

Package Role ctx key
compact/ Abstract compaction seam (interface + compact/* events + CompactionResult) ctx.compact
compact-basic/ A backend: chars-per-token estimation (charsPerToken, default 4) + token-budget retention + llm.stream() summarization (registers ctx.compact)
tool-compact/ (deferred) Model-facing /compact tool over ctx.compact (registers on ctx.tools)

The interface lives at compact/compact/, the backend at compact/compact-basic/. Unlike the bash seam, it depends on dsh-session and dsh-llm — its verbs are defined over a Session and its output is the ContentBlock vocabulary, so the contract cannot be expressed without naming them. That deviation from the "interface depends only on cordis" guidance is intentional and recorded in the compaction capability-seam RFC. A tokenizer- or template-based backend would replace compact-basic without touching the interface or the tool.