.agents/memory/2026-03-01-phase-2-pre-compaction-capture-implementation-plan.md

2026-03-01 Session Notes

Phase 2 Pre-Compaction Capture Implementation Plan

The session focused on reviewing a comprehensive implementation plan for Phase 2 of the Signet memory pipeline, targeting a critical pain point: conversation continuity breaking at compaction boundaries in Claude Code.

Problem Statement

Claude Code's connector was missing a PreCompaction hook configuration (unlike OpenCode and OpenClaw), causing rich conversational context to be lost when Claude Code compacts. Native compaction summaries aren't sufficient because they're generated after context destruction and don't persist queryably across sessions.

Solution Architecture

The plan wires PreCompaction capture with two mechanisms:

1. Add PreCompaction hook to Claude Code connector to catch compaction events
2. Capture accumulated state (prompts, memory queries, themes) before context destruction and write to SQLite
3. Enrich periodic and pre-compaction digests with prompt snippets for richer recovery context

Key Implementation Details

Continuity State: Add pendingPromptSnippets field (max 10 snippets, 200 chars each) to capture user prompt previews incrementally via recordPrompt(sessionKey, queryTerms, promptSnippet).

Checkpoints: New trigger types (pre_compaction and session_end) enable distinction between periodic vs critical boundary checkpoints. Pre-compaction checkpoint includes sessionContext, prompt snippets, memory activity, and elapsed duration.

Digest Formatters: Create formatPreCompactionDigest() and formatSessionEndDigest() functions to produce checkpoint digests with progressively richer context (periodic < pre-compaction < session-end).

Hook Configuration: PreCompaction hook in Claude Code invokes signet hook pre-compaction via CLI, which reads sessionContext from stdin, writes checkpoint, then returns guidelines + summaryPrompt for compaction.

Files Modified

Nine files across three packages: connector-claude-code, daemon (continuity state, session checkpoints, hooks), and cli (stdin parsing). Also creates two new test files.

Verification Strategy

Incremental testing via type checking, unit tests, integration tests with manual verification of checkpoint generation on compaction and session-end events.