I’ve deployed my backend canister in Motoko to the IC mainnet, and I’d like to call some of its functions using Candid UI without deploying or using a frontend canister. Just like in ICP Ninja, I’d like to authenticate with Internet Identity using the button on the right side of the Candid UI interface.
My question is: do I need to configure anything to authenticate with Internet Identity directly when interacting with the backend canister on the IC using CandidUI?
This seems to work on ICP Ninja, so I assumed it would also be possible when deploying with icp-cli 1.0.2, even without a frontend canister.
Sorry if this is a basic question or if I’m missing something obvious.
Yes, this is possible, but Internet Identity authentication is handled by the UI/agent you use, not automatically by icp-cli or just by deploying the backend canister.
If you want a simple way to test your mainnet canister without deploying a frontend canister, you can also try B3Forge:
You can search your own mainnet canister ID in B3Forge, load its Candid methods, and interact with them directly.
It also supports workflows, so if you have repeated calls, you can build a reusable flow around your own canister or even across other canisters as well.
So in short: no special backend configuration is needed just for II login in the UI — the important part is whether the tool you use supports authentication and agent identity management. B3Forge is worth trying for that.
Hey, thanks!
This looks like a really great tool, and it actually allows me to call canister methods after signing in with Internet Identity.
Thank you very much for such a detailed explanation and for sharing the link.
And please feel free to share any feedback or issues you run into — B3Forge is still evolving, and real use cases like yours are really helpful.
You can also try the new AI Workflow builder. A simple way to test it with your own canister is to open this link and replace <CanisterID> with your canister ID:
actually the Candid UI deployed on mainnet supports sign-in via II and interact with the backend, too. there is an option to do that on the top right of the UI after you provide the canister id of the backend and it successfully loads.
after having a short DM conversation with @KryL I noticed that the issue is that icp-cli meanwhile advertises the icp.net domain for Candid UI which isn’t supported for II login right now.
