Add-ons Manager API

This API is primarily used to service the about:addons page in clients like Thunderbird and Firefox. This API is deprecated and we do not recommend projects use this API.

Add-ons using the techniques described in this document are considered a legacy technology in Firefox. Don't use these techniques to develop new add-ons. Use WebExtensions instead. If you maintain an add-on which uses the techniques described here, consider migrating it to use WebExtensions.

Starting from Firefox 53, no new legacy add-ons will be accepted on (AMO) for desktop Firefox and Firefox for Android.

Starting from Firefox 57, only extensions developed using WebExtensions APIs will be supported on Desktop Firefox and Firefox for Android.

Even before Firefox 57, changes coming up in the Firefox platform will break many legacy extensions. These changes include multiprocess Firefox (e10s), sandboxing, and multiple content processes. Legacy extensions that are affected by these changes should migrate to use WebExtensions APIs if they can. See the "Compatibility Milestones" document for more information.

A wiki page containing resources, migration paths, office hours, and more, is available to help developers transition to the new technologies.

URL Format

API calls are served by accessing

You may localize the returned content by adding a locale string to this URL as follows:[locale]/api

For example:

The API is versioned. For all calls, the first parameter is the API version. This is optional, and if it's not supplied, the version defaults to 0. This is maintained for compatibility with older versions of Firefox, but may give you some unexpected behavior, so be sure to specify the current API version. The current API version is 1.5.

All API calls only return public add-ons at present.

Available Methods


Returns details of a particular add-on.



The id of the desired add-on, as per AMO.


Requesting returns the information for addon 1865, Adblock Plus.

See the output from this request.

Returns add-ons that match a specified search term. This uses the same search engine as the rest of the site, so only exact matches are supported. The returned searchresults element has up to 10 addon elements describing each individual search result.

Prototype[version]/search/[searchterm]/[optional:searchtype]/[optional:maxresults]/[optional:search_os /[optional:search_version]


The term to match.
The type of results to return. The default, all, requests that only matching extensions and themes be considered. You may also specify extension, theme, plugin, dictionary, or searchengine.
The maximum number of results to return. This is pegged to no more than 30; specifying a larger number will still return no more than 30 results. The total number of available results will be returned in the total_results attribute of the searchresults element. For example:
<searchresults total_results="196">
Specifies the operating system for which to return results; only add-ons compatible with the specified operating system will be returned. The default value is all; other possible values are winnt, darwin, and linux.
Specifies the application version with which the returned add-ons must be compatible.


Searches for add-ons matching "popup". See the output from this request.

Searches for themes matching "nasa". See the output from this request.

Searches for add-ons of any type that match "blue", returning no more than 10 results. Only add-ons that are compatible with the Windows version of Firefox 3 are considered.

See the output from this request.


Returns a randomly ordered and selected list of add-ons.



The type of list to return. The default is recommended; the only other possible value is new. Recommended add-ons are those recommended by AMO editors, while new add-ons are those posted in the last ten days.
The types of add-on to return. The default value is all, but you may specify extension, theme, plugin, directory, or searchengine.
The maximum number of results to return; the default value is 3. This value is capped at 10; if you specify a higher value than 10, no more than ten results are returned.
The operating system for which compatible add-ons should be returned. By default, this is all. You may also specify winnt, darwin, or linux.
The application version with which the returned add-ons must be compatible.


Returns a list of new add-ons. See the output from this request.

Document Tags and Contributors

Last updated by: andymckay-github,