Analytics Engine Configuration
Setup
- Add binding to
wrangler.jsonc - Deploy Worker
- Dataset created automatically on first write
- Query via SQL API
wrangler.jsonc
{
"name": "my-worker",
"analytics_engine_datasets": [
{ "binding": "ANALYTICS", "dataset": "my_events" }
]
}Multiple datasets for separate concerns:
{
"analytics_engine_datasets": [
{ "binding": "API_ANALYTICS", "dataset": "api_requests" },
{ "binding": "USER_EVENTS", "dataset": "user_activity" }
]
}TypeScript
interface Env {
ANALYTICS: AnalyticsEngineDataset;
}
export default {
async fetch(request: Request, env: Env) {
// No await - returns void, fire-and-forget
env.ANALYTICS.writeDataPoint({
blobs: [pathname, method, status], // String dimensions (max 20)
doubles: [latency, 1], // Numeric metrics (max 20)
indexes: [apiKey] // High-cardinality filter (max 1)
});
return response;
}
};Data Point Limits
| Field | Limit | SQL Access |
|---|---|---|
| blobs | 20 strings, 16KB each | blob1...blob20 |
| doubles | 20 numbers | double1...double20 |
| indexes | 1 string, 16KB | index1 |
Write Behavior
| Scenario | Behavior |
|---|---|
| <1M writes/min | All accepted |
| >1M writes/min | Automatic sampling |
| Invalid data | Silent failure (check tail logs) |
Mitigate sampling: Pre-aggregate, use multiple datasets, write only critical metrics.
Query Limits
| Resource | Limit |
|---|---|
| Query timeout | 30 seconds |
| Data retention | 90 days (default) |
| Result size | ~10MB |
Cost
Free tier: 10M writes/month, 1M reads/month
Paid: $0.05 per 1M writes, $1.00 per 1M reads
Environment-Specific
{
"analytics_engine_datasets": [
{ "binding": "ANALYTICS", "dataset": "prod_events" }
],
"env": {
"staging": {
"analytics_engine_datasets": [
{ "binding": "ANALYTICS", "dataset": "staging_events" }
]
}
}
}Monitoring
npx wrangler tail # Check for sampling/write errors-- Check write activity
SELECT DATE_TRUNC('hour', timestamp) AS hour, COUNT(*) AS writes
FROM my_dataset
WHERE timestamp >= NOW() - INTERVAL '24' HOUR
GROUP BY hour