Summary

Session conversation history is silently dropped between consecutive user messages when using zai/glm-5.1 (z.ai-style provider). The first user message and its assistant reply disappear from the session file when the second user message arrives, causing the agent to lose all context.

Environment

• OpenClaw: 2026.5.2 (8b2a6e5)
• Channel: Feishu (via @larksuite/openclaw-lark)
• Default model: zai/glm-5.1
• OS: macOS 26.3.1 (arm64)
• Node: v24.14.1

Reproduction

1. Start a fresh DM session (Feishu channel, zai/glm-5.1 default model)
2. Send a text message → agent replies correctly with full context
3. Send a second message (e.g., attach a docx file) → agent sees ONLY the second message; the first exchange is gone from context

Evidence from session store

First backup (61318122-...jsonl.bak-97174-1777807809142, 7 lines):

[0] session
[1] model_change → qiniu/claude-opus-4-7
[2] thinking_level_change
[4] user: "小宇宙前面两天你帮我做的临时论文…"  ← FIRST MESSAGE (intact)
[5] custom: System inbound metadata
[6] assistant: "聪聪先把最后一版论文发我…"     ← FIRST REPLY (intact)

Second backup (61318122-...jsonl.bak-97174-1777807887760, created ~78s later after docx upload):

[0] session
[1] model_change → qiniu/claude-opus-4-7
[2] thinking_level_change
[3] custom (system prompt)
[4] user: [media attached: ...docx]             ← ONLY docx, first message GONE
[5] custom: [media attached: ...docx]
[6] assistant: "聪聪发了个 docx 文件，但没说要干啥"  ← Agent lost context

Between the two backups (78 seconds apart), the session file was rewritten: the first user message + assistant reply were silently removed. The model_change entry (line 1) was preserved, suggesting the session metadata survived but conversation history did not.

Configuration

{
  "agents": {
    "defaults": {
      "model": { "primary": "zai/glm-5.1" },
      "contextPruning": {
        "mode": "cache-ttl",
        "ttl": "5m",
        "keepLastAssistants": 3,
        "minPrunableToolChars": 30000,
        "hardClear": { "enabled": true }
      }
    }
  },
  "session": {
    "dmScope": "per-channel-peer",
    "maintenance": { "mode": "enforce", "maxEntries": 50, "pruneAfter": "2h" },
    "reset": { "mode": "idle", "idleMinutes": 999999 }
  }
}

The session.reset.idleMinutes: 999999 rules out idle reset as the cause (78s gap is nowhere near the threshold). pruneAfter: 2h also does not explain losing context within seconds.

Related

• CHANGELOG 5.2 mentions: "Agents/compaction: keep prior context on consecutive turns against z.ai-style providers (z.ai direct, openrouter z-ai/*, in-house GLM gateways), avoiding accidental Pi state reset after successful turns. (fix(agents): keep state.messages intact across z.ai-style provider turns in embedded runs #76056)"
• This fix appears to be in 5.2 already, but the issue still reproduces. Either the fix is incomplete or there is a second trigger path.

Impact

• Agent becomes context-blind mid-conversation, requiring user to re-explain everything
• No error is raised — the loss is silent
• Happens reliably on the second user message in a fresh session

Expected Behavior

Session history should accumulate across turns. Prior messages should never be silently dropped without explicit user action (e.g., /new) or configured reset/cleanup thresholds being met.