OpenClaw can expose diagnostics metrics through the official diagnostics-prometheus plugin. It listens to trusted diagnostics plus core-emitted gateway stability events, then renders a Prometheus text endpoint at:

GET /api/diagnostics/prometheus

Content type is text/plain; version=0.0.4; charset=utf-8, the standard Prometheus exposition format.

Warning

The route uses Gateway authentication (operator scope). Do not expose it as a public unauthenticated /metrics endpoint. Scrape it through the same auth path you use for other operator APIs.

For traces, logs, OTLP push, and OpenTelemetry GenAI semantic attributes, see OpenTelemetry export.

Quick start

Install the plugin

```bash
openclaw plugins install clawhub:@openclaw/diagnostics-prometheus
```

Enable the plugin

Config

    ```json5
    {
      plugins: {
        allow: ["diagnostics-prometheus"],
        entries: {
          "diagnostics-prometheus": { enabled: true },
        },
      },
      diagnostics: {
        enabled: true,
      },
    }
    ```

CLI

    ```bash
    openclaw plugins enable diagnostics-prometheus
    ```

Restart the Gateway

The HTTP route is registered at plugin startup, so reload after enabling.

Scrape the protected route

Send the same gateway auth your operator clients use:

```bash
curl -H "Authorization: Bearer $OPENCLAW_GATEWAY_TOKEN" \
  http://127.0.0.1:18789/api/diagnostics/prometheus
```

Wire Prometheus

```yaml
# prometheus.yml
scrape_configs:
  - job_name: openclaw
    scrape_interval: 30s
    metrics_path: /api/diagnostics/prometheus
    authorization:
      credentials_file: /etc/prometheus/openclaw-gateway-token
    static_configs:
      - targets: ["openclaw-gateway:18789"]
```

Note

diagnostics.enabled: true is required. Without it, the plugin still registers the HTTP route but no diagnostic events flow into the exporter, so the response is empty.

Metrics exported

Metric	Type	Labels
openclaw_run_completed_total	counter	channel, model, outcome, provider, trigger
openclaw_run_duration_seconds	histogram	channel, model, outcome, provider, trigger
openclaw_model_call_total	counter	api, error_category, model, outcome, provider, transport
openclaw_model_call_duration_seconds	histogram	api, error_category, model, outcome, provider, transport
openclaw_model_failover_total	counter	from_model, from_provider, lane, reason, suspended, to_model, to_provider
openclaw_model_tokens_total	counter	agent, channel, model, provider, token_type
openclaw_gen_ai_client_token_usage	histogram	model, provider, token_type
openclaw_model_cost_usd_total	counter	agent, channel, model, provider
openclaw_skill_used_total	counter	activation, agent, skill, source
openclaw_tool_execution_total	counter	error_category, outcome, params_kind, tool, tool_owner, tool_source
openclaw_tool_execution_duration_seconds	histogram	error_category, outcome, params_kind, tool, tool_owner, tool_source
openclaw_tool_execution_blocked_total	counter	denied_reason, params_kind, tool, tool_owner, tool_source
openclaw_harness_run_total	counter	channel, error_category, harness, model, outcome, phase, plugin, provider
openclaw_harness_run_duration_seconds	histogram	channel, error_category, harness, model, outcome, phase, plugin, provider
openclaw_webhook_received_total	counter	channel, webhook
openclaw_webhook_error_total	counter	channel, webhook
openclaw_webhook_duration_seconds	histogram	channel, webhook
openclaw_message_received_total	counter	channel, source
openclaw_message_dispatch_started_total	counter	channel, source
openclaw_message_dispatch_completed_total	counter	channel, outcome, reason, source
openclaw_message_dispatch_duration_seconds	histogram	channel, outcome, reason, source
openclaw_message_processed_total	counter	channel, outcome, reason
openclaw_message_processed_duration_seconds	histogram	channel, outcome, reason
openclaw_message_delivery_started_total	counter	channel, delivery_kind
openclaw_message_delivery_total	counter	channel, delivery_kind, error_category, outcome
openclaw_message_delivery_duration_seconds	histogram	channel, delivery_kind, error_category, outcome
openclaw_talk_event_total	counter	brain, event_type, mode, provider, transport
openclaw_talk_event_duration_seconds	histogram	brain, event_type, mode, provider, transport
openclaw_talk_audio_bytes	histogram	brain, event_type, mode, provider, transport
openclaw_queue_lane_size	gauge	lane
openclaw_queue_lane_wait_seconds	histogram	lane
openclaw_session_state_total	counter	reason, state
openclaw_session_queue_depth	gauge	state
openclaw_session_turn_created_total	counter	agent, channel, trigger
openclaw_session_stuck_total	counter	reason, state
openclaw_session_stuck_age_seconds	histogram	reason, state
openclaw_session_recovery_total	counter	action, active_work_kind, state, status
openclaw_session_recovery_age_seconds	histogram	action, active_work_kind, state, status
openclaw_liveness_warning_total	counter	reason
openclaw_liveness_sessions	gauge	state
openclaw_liveness_event_loop_delay_p99_seconds	histogram	reason
openclaw_liveness_event_loop_delay_max_seconds	histogram	reason
openclaw_liveness_event_loop_utilization_ratio	histogram	reason
openclaw_liveness_cpu_core_ratio	histogram	reason
openclaw_payload_large_total	counter	action, channel, plugin, reason, surface
openclaw_payload_large_bytes	histogram	action, channel, plugin, reason, surface
openclaw_memory_bytes	gauge	kind
openclaw_memory_rss_bytes	histogram	none
openclaw_memory_pressure_total	counter	level, reason
openclaw_telemetry_exporter_total	counter	exporter, reason, signal, status
openclaw_prometheus_series_dropped_total	counter	none

Label policy

Bounded, low-cardinality labels

Prometheus labels stay bounded and low-cardinality. The exporter does not emit raw diagnostic identifiers such as `runId`, `sessionKey`, `sessionId`, `callId`, `toolCallId`, message IDs, chat IDs, or provider request IDs.

Label values are redacted and must match OpenClaw's low-cardinality character policy. Values that fail the policy are replaced with `unknown`, `other`, or `none`, depending on the metric. Labels that look like scoped agent session keys are also replaced with `unknown`.

Series cap and overflow accounting

The exporter caps retained time series in memory at **2048** series across counters, gauges, and histograms combined. New series beyond that cap are dropped, and `openclaw_prometheus_series_dropped_total` increments by one each time.

Watch this counter as a hard signal that an attribute upstream is leaking high-cardinality values. The exporter never lifts the cap automatically; if it climbs, fix the source rather than disabling the cap.

What never appears in Prometheus output

- prompt text, response text, tool inputs, tool outputs, system prompts
- Talk transcripts, audio payloads, call ids, room ids, handoff tokens, turn ids, and raw session ids
- raw provider request IDs (only bounded hashes, where applicable, on spans — never on metrics)
- session keys and session IDs
- hostnames, file paths, secret values

PromQL recipes

# Tokens per minute, split by provider
sum by (provider) (rate(openclaw_model_tokens_total[1m]))

# Spend (USD) over the last hour, by model
sum by (model) (increase(openclaw_model_cost_usd_total[1h]))

# 95th percentile model run duration
histogram_quantile(
  0.95,
  sum by (le, provider, model)
    (rate(openclaw_run_duration_seconds_bucket[5m]))
)

# Queue wait time SLO (95p under 2s)
histogram_quantile(
  0.95,
  sum by (le, lane) (rate(openclaw_queue_lane_wait_seconds_bucket[5m]))
) < 2

# Skill usage, split by bounded source
sum by (skill, source) (increase(openclaw_skill_used_total[24h]))

# Dropped Prometheus series (cardinality alarm)
increase(openclaw_prometheus_series_dropped_total[15m]) > 0

Tip

Prefer gen_ai_client_token_usage for cross-provider dashboards: it follows the OpenTelemetry GenAI semantic conventions and is consistent with metrics from non-OpenClaw GenAI services.

Choosing between Prometheus and OpenTelemetry export

OpenClaw supports both surfaces independently. You can run either, both, or neither.

diagnostics-prometheus

- **Pull** model: Prometheus scrapes `/api/diagnostics/prometheus`.
- No external collector required.
- Authenticated through normal Gateway auth.
- Surface is metrics only (no traces or logs).
- Best for stacks already standardized on Prometheus + Grafana.

diagnostics-otel

- **Push** model: OpenClaw sends OTLP/HTTP to a collector or OTLP-compatible backend.
- Surface includes metrics, traces, and logs.
- Bridges to Prometheus through an OpenTelemetry Collector (`prometheus` or `prometheusremotewrite` exporter) when you need both.
- See [OpenTelemetry export](/en/gateway/opentelemetry) for the full catalog.

Troubleshooting

Empty response body

- Check `diagnostics.enabled: true` in config.
- Confirm the plugin is enabled and loaded with `openclaw plugins list --enabled`.
- Generate some traffic; counters and histograms only emit lines after at least one event.

401 / unauthorized

The endpoint requires the Gateway operator scope (`auth: "gateway"` with `gatewayRuntimeScopeSurface: "trusted-operator"`). Use the same token or password Prometheus uses for any other Gateway operator route. There is no public unauthenticated mode.

openclaw_prometheus_series_dropped_total is climbing

A new attribute is exceeding the **2048**-series cap. Inspect recent metrics for an unexpectedly high-cardinality label and fix it at the source. The exporter intentionally drops new series instead of silently rewriting labels.

Prometheus shows stale series after a restart

The plugin keeps state in memory only. After a Gateway restart, counters reset to zero and gauges restart at their next reported value. Use PromQL `rate()` and `increase()` to handle resets cleanly.

Related

• Diagnostics export — local diagnostics zip for support bundles
• Health and readiness — /healthz and /readyz probes
• Logging — file-based logging
• OpenTelemetry export — OTLP push for traces, metrics, and logs