Suggesting content items to be accessed by a user

1. A computing system comprising:

at least one processor; and

at least one non-transitory computer-readable storage medium storing instructions that, when executed by the at least one processor, cause the computing system to:

receive, from an application associated with a first system that is separate from a content management system, an application programming interface (API) call generated during user activity within the application, the user activity comprising a user input to be used within the first system, the API call specifying content item search criteria generated based on the user input to be used within the first system;

based on the content item search criteria specified in the API call, perform a lookup in a user-specific content item index within the content management system associated with a user account to identify at least one content item that satisfies the content item search criteria generated based on the user activity, wherein the user-specific content item index references content items associated with the user account; and

provide, to the application, a suggestion to access the at least one content item from the content management system using the application associated with the first system.

2. The computing system of claim 1 , wherein the application is a client application installed on a client device.

3. The computing system of claim 1 , wherein the application comprises at least one of a web browser, an email application, an electronic messaging application, a text application, or a document editing application.

4. The computing system of claim 1 , wherein the user activity within the application comprises text composition within the application.

5. The computing system of claim 1 , wherein the user activity within the application comprises saving one or more content items to the content management system.

6. The computing system of claim 1 , further comprising instructions that, when executed by the at least one processor, cause the computing system to:

identify a plurality of content items that satisfy the content item search criteria, the plurality of content items comprising the at least one content item; and

wherein providing the suggestion to access the at least one content item comprises providing a list of the plurality of content items.

7. The computing system of claim 1 , wherein the user-specific content item index comprises one or more shared folders that are shared among a group of collaborating users.

8. A computer-implemented method comprising:

receiving, from an application associated with a first system that is separate from a content management system, an application programming interface (API) call generated during user activity within the application, the user activity comprising a user input to be used within the first system, the API call specifying content item search criteria generated based on the user input to be used within the first system;

based on the content item search criteria specified in the API call, performing a lookup in a user-specific content item index within the content management system associated with a user account to identify at least one content item that satisfies the content item search criteria generated based on the user activity, wherein the user-specific content item index references content items associated with the user account; and

providing, to the application, a suggestion to access the at least one content item from the content management system using the application associated with the first system.

9. The computer-implemented method of claim 8 , wherein the application is a client application installed on a client device.

10. The computer-implemented method of claim 8 , wherein the application comprises at least one of a web browser, an email application, an electronic messaging application, a text application, or a document editing application.

11. The computer-implemented method of claim 8 , wherein the user activity within the application comprises actions with respect to content items associated with the user account.

12. The computer-implemented method of claim 8 , wherein the user-specific content item index comprises one or more shared folders that are shared among a group of collaborating users.

13. The computer-implemented method of claim 8 , wherein:

based on the user activity within the application, the content item search criteria comprise a user tag; and

the at least one content item is associated with the user tag.

14. The computer-implemented method of claim 8 , further comprising:

identifying a plurality of content items that satisfy the content item search criteria, the plurality of content items comprising the at least one content item; and

wherein providing the suggestion to access the at least one content item comprises providing a list of the plurality of content items for display within a graphical user interface corresponding to the application.

15. The computer-implemented method of claim 8 , wherein providing the suggestion to access the at least one content item comprises providing an option to attach the at least one content item to a message being composed within the application.

16. A non-transitory computer-readable medium storing instructions thereon that, when executed by at least one processor, cause a computing device to:

receive, from an application associated with a first system that is separate from a content management system, an application programming interface (API) call generated during user activity within the application, the user activity comprising a user input to be used within the first system, the API call specifying content item search criteria generated based on the user input to be used within the first system;

based on the content item search criteria specified in the API call, perform a lookup in a user-specific content item index within the content management system associated with a user account to identify at least one content item that satisfies the content item search criteria generated based on the user activity, wherein the user-specific content item index references content items associated with the user account; and

provide, to the application, a suggestion to access the at least one content item from the content management system using the application associated with the first system.

17. The non-transitory computer-readable medium of claim 16 , wherein the application is a client application installed on a client device.

18. The non-transitory computer-readable medium of claim 16 , wherein the user activity within the application comprises actions with respect to content items associated with the user account.

19. The non-transitory computer-readable medium of claim 18 , wherein:

based on the user activity within the application, the content item search criteria comprise a user tag; and

the at least one content item is associated with the user tag.

20. The non-transitory computer-readable medium of claim 16 , further comprising instructions that, when executed by the at least one processor, cause the computing device to:

identify a plurality of content items that satisfy the content item search criteria, the plurality of content items comprising the at least one content item; and

wherein providing the suggestion to access the at least one content item comprises providing a list of the plurality of content items for display within a graphical user interface corresponding to the application.