Errors & Rate Limits

HTTP status codes

Code	Meaning	Action
`200`	Event accepted	No action needed
`400`	Bad request — missing field, invalid format, or inactive `site_id`	Fix the request payload
`401`	Missing `X-API-Key` header	Add the `X-API-Key` header
`403`	Invalid key, revoked key, or `site_id`/key mismatch	Check your API key and `site_id`
`413`	Payload too large	Reduce payload size or split into smaller batches
`422`	Validation error — see response body for details	Fix the specific field error
`429`	Rate limit exceeded	Back off and retry after the `Retry-After` header value
`500` / `502` / `503`	Server error	Retry with exponential backoff

Error response format

All error responses return a JSON body with details:

{
  "detail": [
    {
      "loc": ["body", "scan_session_id"],
      "msg": "field required",
      "type": "value_error.missing"
    }
  ]
}

For 400 errors with a single message:

{
  "detail": "site_id not found or inactive"
}

Rate limits

Endpoint	Limit	Scope
`POST /ct` (browser events)	100 requests / min	Per IP address
`POST /collect/batch`	100 requests / min	Per IP address
`POST /server-events`	1,000 requests / min	Per API key
`POST /server-events/batch`	1,000 requests / min	Per API key

Short bursts above the limit are handled with a small grace window. Design your clients to back off on 429 rather than relying on burst tolerance.

Error handling pattern

For server events

async function sendEvent(payload) {
  const response = await fetch('https://track.scanova.io/server-events', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'X-API-Key': process.env.SCANOVA_API_KEY,
    },
    body: JSON.stringify(payload),
  });

  if (response.ok) return await response.json();

  const error = await response.json().catch(() => null);

  if (response.status === 429) {
    const retryAfter = parseInt(response.headers.get('Retry-After') ?? '60', 10);
    throw new RetryableError(`Rate limited — retry after ${retryAfter}s`, retryAfter);
  }

  if (response.status >= 500) {
    throw new RetryableError(`Server error ${response.status}`);
  }

  // 400, 401, 403, 422 — do not retry, fix the request
  throw new PermanentError(`Request failed ${response.status}: ${JSON.stringify(error)}`);
}

Retry logic

Only retry on transient errors. Stop immediately on permanent errors.

Retry?	Status codes
Yes — retry with backoff	`429`, `500`, `502`, `503`, `504`, network timeout
No — fix the request	`400`, `401`, `403`, `413`, `422`

See Idempotency & Retries for a full retry implementation with exponential backoff.

Common `422` causes

Error	Fix
`scan_session_id` invalid format	Must be a valid UUID (e.g. `7ad26d4f-3181-4ef8-b6ca-b8f59499dd43`)
`event_name` missing	Required for server events
`conversion_value.currency` invalid	Must be a 3-letter ISO 4217 code (e.g. `USD`, `EUR`, `GBP`)
`properties` too large	Keep under 10 KB
Raw email in `properties`	Use `user_identifiers.email_hash` with a SHA-256 hash instead

Overview

Browser SDK

Server-Side

API Reference

Resources

HTTP status codes

Error response format

Rate limits

Error handling pattern

For server events

Retry logic

Common `422` causes

​HTTP status codes

​Error response format

​Rate limits

​Error handling pattern

​For server events

​Retry logic

​Common 422 causes

HTTP status codes

Error response format

Rate limits

Error handling pattern

For server events

Retry logic

Common `422` causes