# Health and observability API

Probe service liveness, readiness, and Prometheus gauges without credentials —
none of the endpoints on this page require authentication.

## Check liveness

```bash
curl https://api.instantml.ai/health
```

`/healthz` is an alias for the same check. Typical response:

```json
{ "status": "ok" }
```

Use health for process liveness checks.

## Check readiness

```http
GET /readyz
```

Ready response:

```json
{
  "status": "ok",
  "control_projection_loaded": true,
  "control_refresh_degraded": false,
  "write_ready": true,
  "writer_lease": {
    "required": true,
    "ready": true
  }
}
```

Use readiness for load balancers and startup probes. It fails with `503` until
the server can reach ClickHouse and replay the control projection.
`write_ready` mirrors `writer_lease.ready`: when the service plane requires a
writer lease and the lease is not held, writes are not ready and
`writer_lease.code` explains why.

## Scrape Prometheus metrics

```http
GET /metrics
```

The metrics output contains exactly three gauge series:

- `instantml_rust_build_info` — always `1`, labeled with the service and active
  service plane.
- `instantml_control_projection_loaded` — `1` once the control projection has
  replayed.
- `instantml_control_refresh_degraded` — `1` while control-projection refresh
  is degraded.

Request-level metrics are not exposed on this endpoint; use `x-request-id`
correlation and origin logs for per-request debugging.

## Fetch the OpenAPI spec

```http
GET /openapi.json
```

The public docs site consumes a filtered OpenAPI copy. The live service's
OpenAPI output is useful for operator verification because it reports the
active service plane.

## Correlate requests

Responses include an `x-request-id` header. Keep it with support reports:

```bash
curl -i https://api.instantml.ai/healthz
```

Hosted origin logs use this request ID as the primary application correlation
key. Cloudflare Ray IDs can help correlate edge logs, but they are not a
replacement for `x-request-id`.

## Next steps

- [Authenticate API calls](/docs/api/authentication.md)
- [Handle errors, pagination, and limits](/docs/api/errors-and-limits.md)
- [Monitor InstantML in production](/docs/guides/observability.md)
- [Understand the service-plane split](/docs/architecture/service-planes.md)

## Agent navigation

- [Docs index](/llms.txt)
- [Full docs bundle](/llms-full.txt)

### Get Started

- [Overview](/docs/index.md)
- [Quickstart](/docs/quickstart.md)
- [Core Concepts](/docs/concepts/core-concepts.md)
- [Pricing](/docs/pricing.md)
- [Benchmarks](/docs/benchmarks.md)
- [Examples](/docs/guides/examples.md)
- [Troubleshooting](/docs/troubleshooting.md)

### SDK

- [Installation Auth](/docs/sdk/installation-auth.md)
- [Logging](/docs/sdk/logging.md)
- [Tracing](/docs/sdk/tracing.md)
- [Metrics Steps](/docs/sdk/metrics-steps.md)
- [Config Tags Notes](/docs/sdk/config-tags-notes.md)
- [Artifacts Checkpoints](/docs/sdk/artifacts-checkpoints.md)
- [Rich Objects](/docs/sdk/rich-objects.md)
- [Distributed Training](/docs/sdk/distributed-training.md)
- [Console System Integrations](/docs/sdk/console-system-integrations.md)
- [Reliability](/docs/sdk/reliability.md)
- [Cli Login](/docs/sdk/cli-login.md)
- [Querying Data](/docs/sdk/querying-data.md)
- [Agent Mcp](/docs/sdk/agent-mcp.md)
- [Examples Patterns](/docs/sdk/examples-patterns.md)

### Integrations

- [Overview](/docs/integrations/overview.md)
- [Pytorch Lightning](/docs/integrations/pytorch-lightning.md)
- [Huggingface Transformers](/docs/integrations/huggingface-transformers.md)
- [Keras](/docs/integrations/keras.md)
- [Wandb](/docs/integrations/wandb.md)

### Dashboard

- [Tour](/docs/dashboard/tour.md)
- [Organizations Workspaces](/docs/dashboard/organizations-workspaces.md)
- [Runs Workspace](/docs/dashboard/runs-workspace.md)
- [Metrics Charts](/docs/dashboard/metrics-charts.md)
- [Run Detail](/docs/dashboard/run-detail.md)
- [Traces](/docs/dashboard/traces.md)
- [Compare Runs](/docs/dashboard/compare-runs.md)
- [Research Dashboards](/docs/dashboard/research-dashboards.md)
- [Artifacts Files](/docs/dashboard/artifacts-files.md)
- [Run Health](/docs/dashboard/alerts.md)
- [Datasets](/docs/dashboard/datasets.md)
- [Checkpoints](/docs/dashboard/checkpoints.md)
- [Reports](/docs/dashboard/reports.md)
- [Settings Api Keys](/docs/dashboard/settings-api-keys.md)
- [Api Tab](/docs/dashboard/api-tab.md)
- [Onboarding Team Billing](/docs/dashboard/onboarding-team-billing.md)

### Data

- [Imports](/docs/guides/imports.md)
- [W&B alternative](/docs/guides/wandb-alternative.md)
- [InstantML vs MLflow](/docs/guides/instantml-vs-mlflow.md)
- [W&B import guide](/docs/guides/wandb-import-guide.md)
- [W&B and Neptune imports](/docs/guides/wandb-neptune-imports.md)
- [Export Usage Limits](/docs/guides/export-usage-limits.md)
- [Pricing Limits Billing](/docs/guides/pricing-limits-billing.md)
- [Auth Billing Storage](/docs/guides/auth-billing-storage.md)
- [Customer Owned Clickhouse](/docs/guides/customer-owned-clickhouse.md)
- [Observability](/docs/guides/observability.md)

### API

**Practical API guides**

- [Authentication](/docs/api/authentication.md)
- [Errors And Limits](/docs/api/errors-and-limits.md)
- [Health Observability](/docs/api/health-observability.md) (current page)
- [Projects Runs](/docs/api/projects-runs.md)
- [Metrics Series](/docs/api/metrics-series.md)
- [Attributes Objects](/docs/api/attributes-objects.md)
- [Artifacts](/docs/api/artifacts.md)
- [Reports](/docs/api/reports.md)
- [Iframe Embeds](/docs/api/iframe-embeds.md)
- [Import Export Usage](/docs/api/import-export-usage.md)
- [Dashboard Control State](/docs/api/dashboard-control-state.md)
**Architecture**

- [System Overview](/docs/architecture/system-overview.md)
- [Service Planes](/docs/architecture/service-planes.md)
- [Storage Model](/docs/architecture/storage-model.md)
- [Google Clickhouse](/docs/architecture/google-clickhouse.md)
- [Auth Tenancy](/docs/architecture/auth-tenancy.md)
- [Schema Reference](/docs/architecture/schema-reference.md)

### API Reference

- [API Reference](/docs/api-reference.md)