---
id: 'logs-field-reference'
title: 'Log sources and fields'
description: 'Log sources, ClickHouse fields, and event capture limits'
---

Each event is a row in the ClickHouse `logs` table. Filter the `source` column to select a service. The tables below list its fields; a field is not necessarily populated on every event.

`id`, `timestamp`, `event_message`, `severity_text`, and `source` are top-level columns. Service fields are string values in `log_attributes`, even when the original event contains a number or boolean. Use the **ClickHouse query field** column directly. See [Query logs with SQL](/docs/guides/observability/advanced-log-filtering) for casting and field discovery.

## Sources

| `source`             | Events                                                            |
| -------------------- | ----------------------------------------------------------------- |
| `edge_logs`          | HTTP requests through the API gateway, including REST and GraphQL |
| `postgres_logs`      | Database activity, statements, and errors                         |
| `postgrest_logs`     | PostgREST server logs                                             |
| `auth_logs`          | Auth server: login, JWT, OAuth, email                             |
| `auth_audit_logs`    | Auth audit events                                                 |
| `storage_logs`       | Storage API: uploads and object access                            |
| `realtime_logs`      | Realtime server: channels, presence, broadcast                    |
| `function_edge_logs` | HTTP request and response for an Edge Function invocation         |
| `function_logs`      | `console` output from inside an Edge Function                     |
| `supavisor_logs`     | Shared pooler: pooling and timeouts                               |
| `pgbouncer_logs`     | Dedicated pooler                                                  |
| `pg_upgrade_logs`    | Database version upgrade                                          |

For `postgres_logs`, statement text and error details can appear in `event_message`. A missing structured field does not mean the event has no detail.

## Captured HTTP headers

API Gateway logs capture only the headers below. Other headers still reach the application and client but are omitted from these logs.

Request headers:

- `accept`
- `cf-connecting-ip`
- `cf-ipcountry`
- `host`
- `user-agent`
- `x-forwarded-proto`
- `referer`
- `content-length`
- `x-real-ip`
- `x-client-info`
- `x-forwarded-user-agent`
- `range`
- `prefer`

Response headers:

- `cf-cache-status`
- `cf-ray`
- `content-location`
- `content-range`
- `content-type`
- `content-length`
- `date`
- `transfer-encoding`
- `x-kong-proxy-latency`
- `x-kong-upstream-latency`
- `sb-gateway-mode`
- `sb-gateway-version`

## Capture limits

- Hosted Postgres events longer than 100,000 characters and Edge Function log messages longer than 10,000 characters are truncated.
- Internal Supabase service connection events are not recorded in hosted Postgres logs.
- An Edge Function invocation uses `function_edge_logs`; its console output uses `function_logs`.
- For [API Load Balancer](/docs/guides/platform/read-replicas#api-load-balancer) traffic, `log_attributes['load_balancer_redirect_identifier']` identifies the upstream database.

## Fields by source

<SharedData data="logConstants">
  {(logConstants) => (
    <Tabs scrollable size="small" type="underlined" defaultActiveId="edge_logs" queryGroup="source">
      {logConstants.schemas.map((schema) => (
        <TabPanel id={schema.reference} key={schema.reference} label={schema.name}>
          <p>
            Source: <code>{schema.reference}</code>
          </p>
          <div className="border rounded-md divide-y overflow-hidden">
            {schema.fields
              .sort((a, b) => a.path.localeCompare(b.path))
              .map((field) => {
                const shortName = field.path.replace(/^metadata\./, '')
                const isTopLevel = field.queryField === field.path
                return (
                  <div key={field.path} className="px-4 py-3">
                    <div className="flex items-center gap-2 flex-wrap">
                      <code className="text-sm">{shortName}</code>
                      <span className="text-xs font-mono text-foreground-lighter bg-surface-200 px-1.5 py-0.5 rounded">
                        {field.type}
                      </span>
                    </div>
                    {!isTopLevel && (
                      <div className="mt-2 flex flex-col gap-1">
                        <div className="flex items-baseline gap-2">
                          <span className="text-[10px] font-medium uppercase tracking-wide text-foreground-lighter border rounded px-1.5 py-px shrink-0">
                            schema
                          </span>
                          <code className="text-xs text-foreground-lighter break-all">
                            {field.path}
                          </code>
                        </div>
                        <div className="flex items-baseline gap-2">
                          <span className="text-[10px] font-medium uppercase tracking-wide text-foreground-lighter border rounded px-1.5 py-px shrink-0">
                            clickhouse
                          </span>
                          <code className="text-xs text-foreground-lighter break-all">
                            {field.queryField}
                          </code>
                        </div>
                      </div>
                    )}
                  </div>
                )
              })}
          </div>
        </TabPanel>
      ))}
    </Tabs>
  )}
</SharedData>