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

# Introduction to Zuddl APIs

> Learn the basic details about Zuddl's open APIs 

Zuddl RESTful APIs let you interact with the Zuddl platform and take action for your event or webinar. They let you add attendees, get attendee details, get event details, and more.

The API response is returned in JSON, which your systems can easily consume.

The API parameters allow you to customize the response using filters, sorting, pagination, and other parameters. Parameter values should be percent-encoded (URL-encoded) to ensure correct transmission, especially if they contain special characters such as spaces, semi-colons, or slashes.

# API Base URL

Zuddl hosts APIs in multiple regions. Use the base URL for the region your Zuddl account is hosted in — an API key issued in one region is not valid in another.

**US region (default)**

```
https://api.zuddl.com/
```

**EU region**

```
https://api.eu.zuddl.com/
```

<Note>
  To find your region, look at the domain you use to sign in to the Zuddl dashboard. If it contains `eu`, use the EU base URL. Otherwise, use the US base URL. Learn more about the [EU region](/getting-started/eu-region).
</Note>

# API key

An API key is a token that you provide when making API calls. You must provide your API key in a header parameter called `Authorization`. For example: `Authorization: 123`

You can access your API keys from the **Settings** > **API Access Key** on the dashboard home page. [Learn how to access/generate your API key](https://support.zuddl.com/kb/article/1008/how-to-access-your-api-keys).

# Rate limits

| Metrics                                 | Value             |
| --------------------------------------- | ----------------- |
| Request/second                          | 10                |
| Burst (no. of concurrect calls allowed) | 100 requests      |
| Total quota                             | 10000requests/day |

## Error codes

| Code                           | Trigger                                                                                                                                                                                                                                                                      |
| ------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **400** Bad Request            | Bad param type, malformed JSON, invalid filter/sort/path/query params.                                                                                                                                                                                                       |
| **401** Unauthorized           | Missing `Authorization` header; invalid/unknown API key; **API-key scope mismatch also returns 401, not 403**.                                                                                                                                                               |
| **403** Forbidden              | Authenticated, but context is not an API-key user hitting an API-key-only endpoint.                                                                                                                                                                                          |
| **404** Not Found              | Referenced resource doesn't exist / not in your org (event, session, speaker, sponsor, location, attendee); unmatched route.                                                                                                                                                 |
| **405** Method Not Allowed     | Right path, wrong HTTP verb (e.g. `POST` to a read-only endpoint).                                                                                                                                                                                                           |
| **406** Not Acceptable         | `Accept` header requests a media type the endpoint can't produce. All `/v1/**` endpoints produce only `application/json` — `Accept: application/xml`, `text/html`, `text/csv`, or a malformed `Accept` triggers it. Fix: send `Accept: application/json`, `*/*`, or omit it. |
| **409** Conflict               | Duplicate/conflicting resource state (e.g. creating something that already exists).                                                                                                                                                                                          |
| **415** Unsupported Media Type | On POST/PUT, `Content-Type` isn't `application/json`.                                                                                                                                                                                                                        |
| **422** Unprocessable Entity   | Well-formed, syntactically valid request that violates a business rule.                                                                                                                                                                                                      |
| **429** Too Many Requests      | Exceeding published limits: 10 req/sec, 100 concurrent, 10,000 req/day.                                                                                                                                                                                                      |
| **500** Internal Server Error  | Unhandled server error.                                                                                                                                                                                                                                                      |
| **503** Service Unavailable    | Transient dependency/infra unavailability.                                                                                                                                                                                                                                   |