If you are building an end-user application, you can use the `/autocomplete` endpoint alongside `/search` to enable real-time feedback. This type-ahead functionality helps users find what they are looking for, without requiring them to fully specify their search term. Typically, the user starts typing and a drop-down list appears where they can choose the term from the list below.
To build a query with autocomplete, you need a `text` parameter, representing what a user has typed into your application so far. Optionally, you can specify a geographic point where the search is focused, this will allow users to see more local places in the results.
**Requests must be throttled.** Since autocomplete requests generally correspond directly to user input, it's important to account for fast typers and throttle requests when using the autocomplete endpoint. Mapzen Search has a per second rate limit (that defaults to 6 requests per second), but some devices and networks (for example, mobile phones on a slow connection) may also respond poorly when too many requests are sent too quickly, so be sure to do some testing on your own. [Learn more in this interactive demo.](http://jsfiddle.net/missinglink/19e2r2we/)
**Responses are asynchronous.** This means you cannot be sure responses will be returned in the same order they were requested. If you were to send two queries synchronously, first `'Lo'` then `'London'`, you may find the `'London'` response would arrive before the `'Lo'` response. This will result in a quick flash of `'London'` results followed by the results for `'Lo'`, which can confuse the user.
To focus your search based upon a geographical area, such as the center of the user's map or at the device's GPS location, supply the parameters `focus.point.lat` and `focus.point.lon`. This boosts locally relevant results higher. For example, if you search for `Union Square`:
The `/autocomplete` endpoint can promote nearby results to the top of the list, while still allowing important matches from farther away to be visible. For example, searching `hard rock cafe` with a focus on Berlin:
> [/v1/autocomplete?api_key=your-mapzen-api-key&__focus.point.lat=52.5&focus.point.lon=13.3&text=hard rock cafe__](https://search.mapzen.com/v1/autocomplete?focus.point.lat=52.5&focus.point.lon=13.3&text=hard rock cafe)
Sometimes your work might require that all the search results be from a particular country. To do this, you can set the `boundary.country` parameter value to the alpha-2 or alpha-3 [ISO-3166 country code](https://en.wikipedia.org/wiki/ISO_3166-1).
