Bug Report: shouldSyncSessions skips session data during full reindex triggered by session-start

Summary

When a full reindex is triggered during a session-start sync (e.g., due to model mismatch after gateway restart), session transcript data is silently dropped from the index. The metadata still reports sources: ["memory", "sessions"], masking the data loss.

Version

OpenClaw 2026.3.8 (3caab92)

Steps to Reproduce

1. Configure an agent with experimental.sessionMemory: true and sources: ["memory", "sessions"]
2. Create a state where the agent's index metadata differs from the resolved config (e.g., embedding model mismatch — DB has text-embedding-3-small, config resolves to text-embedding-3-large)
3. Restart the gateway
4. Send a message to the agent (triggers warmSession → sync({ reason: "session-start" }))

Expected Behavior

The full reindex should include both memory files AND session transcripts, since the agent is configured with sources: ["memory", "sessions"].

Actual Behavior

The full reindex only syncs memory files. Session transcript data is dropped from the new index database. The index metadata still reports sources: ["memory", "sessions"], hiding the regression.

Root Cause

In src/memory/manager-sync-ops.ts, the shouldSyncSessions method has a priority bug:

shouldSyncSessions(params, needsFullReindex = false) {
    if (!this.sources.has("sessions")) return false;
    if (params?.force) return true;
    const reason = params?.reason;
    if (reason === "session-start" || reason === "watch") return false;  // ← returns before checking needsFullReindex
    if (needsFullReindex) return true;
    return this.sessionsDirty && this.sessionsDirtyFiles.size > 0;
}

The session-start early return (line 4) fires before the needsFullReindex check (line 5). This means when a full reindex is needed but triggered by a session starting, sessions are skipped.

The call chain:

1. warmSession() → sync({ reason: "session-start" })
2. sync() detects needsFullReindex = true (model/provider/config mismatch)
3. Calls runSafeReindex({ reason: "session-start" })
4. runSafeReindex calls shouldSyncSessions({ reason: "session-start" }, true)
5. Returns false because session-start short-circuits before needsFullReindex is checked
6. New database is built with only memory files
7. writeMeta() writes sources: ["memory", "sessions"] from config — masking the loss

Suggested Fix

Reorder the checks so needsFullReindex takes priority over the incremental-sync skip:

shouldSyncSessions(params, needsFullReindex = false) {
    if (!this.sources.has("sessions")) return false;
    if (params?.force) return true;
    if (needsFullReindex) return true;  // ← moved before session-start check
    const reason = params?.reason;
    if (reason === "session-start" || reason === "watch") return false;
    return this.sessionsDirty && this.sessionsDirtyFiles.size > 0;
}

The session-start / watch skip is correct for incremental syncs (don't burn resources on every session start), but should not apply when a full reindex is required — full reindexes need all data or the new database is incomplete.

Conditions That Trigger needsFullReindex

Any of these being true during a session-start sync will cause session data loss:

• !meta — no metadata in DB
• meta.model !== provider.model — embedding model change
• meta.provider !== provider.id — embedding provider change
• meta.providerKey !== providerKey — API key rotation
• metaSourcesDiffer(meta, configuredSources) — sources config change
• meta.chunkTokens !== settings.chunking.tokens — chunk size change
• meta.chunkOverlap !== settings.chunking.overlap — chunk overlap change
• vectorReady && !meta?.vectorDims — vector extension loaded after initial build

Impact

In our deployment (15 agents), this bug has caused recurring session data loss across 3 separate incidents over 3 days. Each time, manual openclaw memory index --force (which bypasses the bug via force: true) fixes it, but the regression returns after the next gateway restart because the underlying trigger conditions persist.

File Reference

dist/manager-Ch8Hmvy3.js — shouldSyncSessions method (corresponds to src/memory/manager-sync-ops.ts in source)