Summary

After upgrading from 2026.3.2 to 2026.3.8, MiniMax-M2.5 lastCallUsage always returns zeros for all token fields. This was working correctly in 2026.3.2.

Reproduction

openclaw agent --agent main --message "ping" --json

result.meta.agentMeta.lastCallUsage:

{
  "input": 0,
  "output": 0,
  "cacheRead": 0,
  "cacheWrite": 0,
  "total": 0
}

Evidence

Prometheus openclaw_tokens_total metric shows MiniMax tokens were being recorded correctly under 2026.3.2 up until the upgrade point. After upgrading to 2026.3.8, MiniMax series stopped emitting while OpenRouter/Gemini continues to report normally.

Environment

• OpenClaw: 2026.3.8 (3caab92)
• Model: minimax/MiniMax-M2.5 (via https://api.minimax.io)
• Platform: Raspberry Pi (aarch64), Node v22.18.0
• OTEL: diagnostics-otel plugin → Prometheus OTLP receiver (working for other metrics)

Expected

lastCallUsage should contain non-zero token counts as it did in 2026.3.2.