Is there a way right now to validate or ensure a version of a canister being called? I was thinking about a scenario where I ONLY want to call the canister that has a specific binary running, not any ‘updated’ versions, or just fail/error. In other blockchains, the immutability allows for the use …

Even users can’t be sure. Because code hash could have changed between the time you checked it (via dfx canister info) and the time you make the call. Even if you check after you make the call, and see the code hash was the same, it still can’t prove anything – because some one could have done an up…

Currently this is only possible for external users (i.e not inter-canister calls) as far as I know. As an external user you can access public metadata via the read_state API . This includes the module hash.

That solves most of the problems but in theory, the time between accessing the module_hash and making an external api call to a function, the module could change right? Very unlikely but just thinking out loud

[image] Gekctek: I was just wondering if there was a way now/in the future to restrict a canister call based on canister version/canister binary hash. You could add an explicit argument for version number or binary hash to your functions. The caller would supply the argument and the canister …

Fair point, but a use case I’m trying to figure out if if the canister is not trusted. In theory the canister can be updated to not have that check or it might not be there at all. It would probably have to be an IC protocol check which sounds like doesn’t exist

Maybe CanisterStatus ? [image] Agent-JS 0.11.2 JavaScript Hey everyone, wanted to share that a new version of agent-js is out! This includes an update to the default behavior of the authClient, so that it logs out and reloads the page by default. There’s a flag to overrid…

[image] Gekctek: That solves most of the problems but in theory, the time between accessing the module_hash and making an external api call to a function, the module could change right? Very unlikely but just thinking out loud Yes, I think you’re right. Although unlikely, you’re not guarantee…

There is a ‘black hole’ canister at e3mmv-5qaaa-aaaah-aadma-cai. If it reports that it is the only controller of a canister, then that canister is immutable. You can use that as a programmatic constraint.

I would just like to say I LOVE the Internet Computer community. Everyone is working on something. Essentially everything is open source. There is always something new to learn This is great. Thank you

[image] Gekctek: I would just like to say I LOVE the Internet Computer community. I could not agree more!

Just came across this discussion which is very much related: System API: Introduce a canister generation counter by nomeata · Pull Request #19 · dfinity/interface-spec · GitHub

Canister version validation when making an api call

Developers

paulyoung May 31, 2022, 3:47am 6

Maybe CanisterStatus?

Topic		Replies	Views
Any way to know if a canister was updated? Developers	15	1772	January 15, 2022
Canister_info canister_version skips numbers when receiving update method calls Developers	1	175	December 15, 2023
Feature suggestion: Validate module hash Developers Discussing , community-consideration	19	271	July 4, 2024
Sender_canister_version Language Support	6	67	May 5, 2025
Canister integrity verification on chain is missing Developers	17	1595	January 19, 2022

Canister version validation when making an api call

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