No
Full text of the AGPL 3.0 is here
Below is just a paraphrased summary
IANAL & IANYL but as I understand it:
There are 2 times that the AGPL makes people release code.
- Section 10: If you convey a modified or unmodified version of the work it will be under the this (AGPL) license.
- Section 13: If if you modify the Program, your modified version must offer all users interacting with it remotely an opportunity to receive (have conveyed) the source code, which will be licensed AGPL (by the above)
The normal GPL only triggers on the first of these. Which mean people could create a derivative work, but never actually convey it to the user -- just expose it as a networked service. The AGPL is suppose to fix that case.
So section 10 applies to both modified and unmodified versions. But section 13 only to modified versions.
Since you built a client, and not a server, It is clear that section 13 does not apply to you, since you are not providing any one access to you're a modified version of the work over the network.
Unless you did something like copy paste a bunch of code from the servers source into your client (which you might have done, I can think of a few reasons.). At that point your client might actually be considered as being derived from the server, and someone might argue that being a client is kinda giving people access, since HTTP is a two way protocol. I think it is a stretch though. But in that case, if you convey your work, you would certainly have to worry about Section 10.