> ## Documentation Index
> Fetch the complete documentation index at: https://docs.radarboard.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Caching

> How API responses are cached to reduce external API calls and improve performance.

# Caching

All external API calls go through a cache-first strategy to minimize rate limit hits and improve response times.

## How it works

```
Request arrives
      │
      ▼
  Is forceRefresh set? ──Yes──▶ Call external API
      │No                              │
      ▼                                ▼
  Check cache                    Write to cache
      │                                │
      ▼                                ▼
  Fresh? (within TTL) ──Yes──▶ Return cached data
      │No
      ▼
  Call external API
      │
      ├── Success ──▶ Write to cache ──▶ Return fresh data
      │
      └── Failure ──▶ Return stale cache (with _stale: true)
```

## Cache TTLs per service

| Service               | Cache TTL  | Notes                     |
| --------------------- | ---------- | ------------------------- |
| OpenPanel             | 60 seconds | Live visitors: 15 seconds |
| BetterStack           | 1 minute   | --                        |
| Sentry                | 2 minutes  | Projects: 10 minutes      |
| Linear                | 2 minutes  | Teams: 1 hour             |
| GitHub                | 2 minutes  | --                        |
| Vercel                | 2 minutes  | Domains: 5 minutes        |
| RevenueCat            | 5 minutes  | Rate limited: 5 req/min   |
| Google Search Console | 5 minutes  | --                        |
| Open Collective       | 5 minutes  | --                        |
| App Store Connect     | 15 minutes | Rate limited: 200 req/min |

## Stale fallback

When an external API call fails (network error, rate limit, etc.), the system falls back to the most recent cached data, even if it's past its TTL. The response includes a `_stale: true` flag so the UI can indicate the data may not be current.

## Cache storage

Cache is stored in the `api_cache` table of your configured database provider. See [Database Providers](/developer-guide/database-providers).

## Force refresh

Pass `forceRefresh: true` to bypass the cache and fetch fresh data. This is used by the [Backup System](/developer-guide/backup-system) to proactively warm the cache.