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

# Errors

> Status codes and the error response shape returned by the Nowadays REST API.

The REST API uses standard HTTP status codes. A `2xx` means success; a `4xx`
means the request was rejected; a `5xx` means something failed on our side.

## Error response shape

Every error returns the same JSON body:

```json theme={null}
{
  "success": false,
  "error": "Event not found"
}
```

The `error` string is a human-readable description of what went wrong. Successful
responses do not include the `success` field — they return the resource directly.

Write endpoints add detail where it helps you fix the request. A rejected
`PATCH` lists every problem at once rather than the first:

```json theme={null}
{
  "message": "Some fields could not be accepted.",
  "errors": [
    "numPeople: must be a number of 0 or more.",
    "decisionFactors: 'Vibes' is not a recognized value. Valid: …"
  ]
}
```

A conflict that would drop agenda sessions names them in `orphanedSessions` —
see [Writing events](/api/writing-events).

## Status codes

| Status | Meaning               | When                                                                                                                                                                  |
| ------ | --------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `400`  | Bad Request           | A path or query parameter is malformed (e.g. an event `id` that isn't a valid UUID), or a write was rejected. Nothing is written on a `400`.                          |
| `401`  | Unauthorized          | The `x-api-key` header is missing or invalid. See [Authentication](/api/authentication).                                                                              |
| `403`  | Forbidden             | The key's user does not belong to the organization the write targets.                                                                                                 |
| `404`  | Not Found             | The resource doesn't exist **or** isn't accessible to your key's user — the two are indistinguishable, so you never learn whether another organization's data exists. |
| `409`  | Conflict              | The event is cancelled, or the change would drop agenda sessions. Nothing is written. See [Writing events](/api/writing-events).                                      |
| `429`  | Too Many Requests     | You've exceeded the rate limit. See [Rate limits](/api/rate-limits).                                                                                                  |
| `500`  | Internal Server Error | An unexpected error on our side. Retry; if it persists, [contact us](mailto:support@nowadays.ai).                                                                     |

<Note>
  A `404` is returned for both missing and inaccessible resources by design.
  Don't treat it as proof that an `id` is invalid — only that it isn't readable
  with your key.

  Every `4xx` on a write means **nothing was written**, so it is always safe to
  correct the request and retry without first checking what partially landed.
</Note>