# CDK **URL:** https://forum.dfinity.org/c/developers/cdk/36.md [Latest](https://forum.dfinity.org/latest.md) · [Categories](https://forum.dfinity.org/categories.md) · [Tags](https://forum.dfinity.org/tags.md) --- ## [About the CDK category](https://forum.dfinity.org/t/about-the-cdk-category/16191)
**Author:** [@anon74414410](https://forum.dfinity.org/u/anon74414410)\ **Replies:** 0
This category is intended to aggregate posts, questions, and discussion of Canister Development Kits for the Internet Computer --- ## [Writing Smart Contracts on ICP in Go – A First Step](https://forum.dfinity.org/t/writing-smart-contracts-on-icp-in-go-a-first-step/42909)
**Author:** [@quint](https://forum.dfinity.org/u/quint)\ **Replies:** 14\ **Last updated:** [May 11, 2026, 3:34pm UTC](https://forum.dfinity.org/t/writing-smart-contracts-on-icp-in-go-a-first-step/42909 "2026-05-11T15:34:05Z")
The Internet Computer has officially supported writing canisters in Rust and Motoko for a while now. But the ecosystem has been expanding, with community efforts enabling smart contract development in other languages lik… --- ## [Idea Discussion:: On-Chain AI Red-Teaming Sandbox for DeAI Models](https://forum.dfinity.org/t/idea-discussion-on-chain-ai-red-teaming-sandbox-for-deai-models/60222)
**Author:** [@Jaydev](https://forum.dfinity.org/u/Jaydev)\ **Replies:** 0\ **Last updated:** [November 22, 2025, 1:45pm UTC](https://forum.dfinity.org/t/idea-discussion-on-chain-ai-red-teaming-sandbox-for-deai-models/60222 "2025-11-22T13:45:38Z")
Hi ICP Community! I was wondering that, even though the IC enables AI inference to run directly inside tamper-evident canisters, I felt that it still lacks a controlled execution environment where developers can run har… --- ## [Running dfx on my public ip address](https://forum.dfinity.org/t/running-dfx-on-my-public-ip-address/34430)
**Author:** [@AkshitV](https://forum.dfinity.org/u/AkshitV)\ **Replies:** 2\ **Last updated:** [November 5, 2025, 8:26am UTC](https://forum.dfinity.org/t/running-dfx-on-my-public-ip-address/34430 "2025-11-05T08:26:32Z")
I am trying to run dfx on my public ip using this command : dfx start --host ‘publicIp:port’ The error i am getting: Error: Failed to get frontend address. Caused by: Failed to find reusable socket address Caused by… --- ## [Testing evm\_rpc with dfx](https://forum.dfinity.org/t/testing-evm-rpc-with-dfx/59228)
**Author:** [@skilesare](https://forum.dfinity.org/u/skilesare)\ **Replies:** 3\ **Last updated:** [October 23, 2025, 11:50am UTC](https://forum.dfinity.org/t/testing-evm-rpc-with-dfx/59228 "2025-10-23T11:50:01Z")
I’m having some issue with evm\_rpc when testing locally. 2025-10-22 16:46:52.956405 UTC: \[Canister uzt4z-lp777-77774-qaabq-cai\] ("Cycles to Add", 1\_780\_784\_000) 2025-10-22 16:46:52.956405 UTC: \[Canister uzt4z-lp777-7777… --- ## [Open Call to Review Azle's Security](https://forum.dfinity.org/t/open-call-to-review-azles-security/55791)
**Author:** [@lastmjs](https://forum.dfinity.org/u/lastmjs)\ **Replies:** 9\ **Last updated:** [October 3, 2025, 3:49pm UTC](https://forum.dfinity.org/t/open-call-to-review-azles-security/55791 "2025-10-03T15:49:25Z")
Hello ICP developer community! My name is Jordan Last, the leader of Demergent Labs, an independent company and DFINITY grantee which has been developing the Azle (TypeScript/JavaScript) and Kybra (Python) CDKs since 20… --- ## [Http Calls not working](https://forum.dfinity.org/t/http-calls-not-working/54005)
**Author:** [@shashikant](https://forum.dfinity.org/u/shashikant)\ **Replies:** 1\ **Last updated:** [July 28, 2025, 2:10pm UTC](https://forum.dfinity.org/t/http-calls-not-working/54005 "2025-07-28T14:10:00Z")
I want to use the http calls to connect with offchain data but the latest cdk version has depricated it and i need to use the latest version how can i resolve it or any alternative --- ## [Deploying Solidity Contracts from Hardhat to ICP](https://forum.dfinity.org/t/deploying-solidity-contracts-from-hardhat-to-icp/53842)
**Author:** [@telasius](https://forum.dfinity.org/u/telasius)\ **Replies:** 2\ **Last updated:** [July 25, 2025, 6:34pm UTC](https://forum.dfinity.org/t/deploying-solidity-contracts-from-hardhat-to-icp/53842 "2025-07-25T18:34:56Z")
Hello, I’m posting this question on behalf of my developer. We want to deploy Solidity contracts to the Internet Computer Protocol (ICP) using Hardhat. The goal is to simply add a private key and the correct RPC endpoi… --- ## [Deployment error with dfx](https://forum.dfinity.org/t/deployment-error-with-dfx/53717)
**Author:** [@shaker100](https://forum.dfinity.org/u/shaker100)\ **Replies:** 2\ **Last updated:** [July 24, 2025, 10:08am UTC](https://forum.dfinity.org/t/deployment-error-with-dfx/53717 "2025-07-24T10:08:59Z")
Hello, I created a new project with: dfx new hello --type motoko --frontend react and I get an error after trying to deploy the hello project by the command: dfx deploy --playground. The error: Error: The frontend ca… --- ## [Canister Dapps: A brief introduction](https://forum.dfinity.org/t/canister-dapps-a-brief-introduction/53650)
**Author:** [@Samer](https://forum.dfinity.org/u/Samer)\ **Replies:** 3\ **Last updated:** [July 21, 2025, 10:27pm UTC](https://forum.dfinity.org/t/canister-dapps-a-brief-introduction/53650 "2025-07-21T22:27:39Z")
Hello all, In short: This year I started working on My Canister Dapp, a toolchain to develop single canister decentralized applications that are created and controlled by only using Internet Identity. There’s a FAQ on… --- ## [Something wrong with dfx version 0.26.0](https://forum.dfinity.org/t/something-wrong-with-dfx-version-0-26-0/47517)
**Author:** [@Guangxin](https://forum.dfinity.org/u/Guangxin)\ **Replies:** 12\ **Last updated:** [July 9, 2025, 3:51am UTC](https://forum.dfinity.org/t/something-wrong-with-dfx-version-0-26-0/47517 "2025-07-09T03:51:58Z")
I upgrade my dfx from 0.24.0 to 0.26.0, then i keep getting error said CanisterIdNotFound Also, when run ‘dfx start --clean --background’, it looks like not actually running at background, i can’t keep typing any other … --- ## [Ic-cdk v0.18.2 Release: Important Update on Version Compatibility](https://forum.dfinity.org/t/ic-cdk-v0-18-2-release-important-update-on-version-compatibility/47963)
**Author:** [@AdamS](https://forum.dfinity.org/u/AdamS)\ **Replies:** 13\ **Last updated:** [June 18, 2025, 1:01pm UTC](https://forum.dfinity.org/t/ic-cdk-v0-18-2-release-important-update-on-version-compatibility/47963 "2025-06-18T13:01:56Z")
Update: Out of an abundance of caution, we yanked 0.18.2 pending internal security review. To reiterate, we do not believe the issues reported about 0.18.1 are caused by any internal bugs, but the seriousness of those re… --- ## [Ic-cdk 0.18.3 released](https://forum.dfinity.org/t/ic-cdk-0-18-3-released/49637)
**Author:** [@AdamS](https://forum.dfinity.org/u/AdamS)\ **Replies:** 1\ **Last updated:** [June 5, 2025, 3:33pm UTC](https://forum.dfinity.org/t/ic-cdk-0-18-3-released/49637 "2025-06-05T15:33:26Z")
Hi everyone, We’ve released ic-cdk v0.18.3. This release brings the removal of a few edge cases from v0.18.2, as well as support for the new root\_key API and mirroring mainnet parameters for Bitcoin regtest. If you are… --- ## [🚀 Introducing Second Mountain: Decentralized Portfolio Management on ICP](https://forum.dfinity.org/t/introducing-second-mountain-decentralized-portfolio-management-on-icp/44600)
**Author:** [@Hanu](https://forum.dfinity.org/u/Hanu)\ **Replies:** 0\ **Last updated:** [April 23, 2025, 7:13pm UTC](https://forum.dfinity.org/t/introducing-second-mountain-decentralized-portfolio-management-on-icp/44600 "2025-04-23T19:13:34Z")
Title: :rocket: Introducing Second Mountain: Decentralized Portfolio Management on ICP Body: Hello ICP community, I’m excited to share our latest project, Second Mountain—a fully permissionless portfolio management pl… --- ## [Bridging BTC to a canister with post execution](https://forum.dfinity.org/t/bridging-btc-to-a-canister-with-post-execution/42702)
**Author:** [@Norfolks](https://forum.dfinity.org/u/Norfolks)\ **Replies:** 8\ **Last updated:** [April 10, 2025, 10:17am UTC](https://forum.dfinity.org/t/bridging-btc-to-a-canister-with-post-execution/42702 "2025-04-10T10:17:10Z")
Hi, I am currently building a pool staking application for native bitcoin users, so users are not expected to use any ICP wallets. Each pool has several locktime options: 90, 180, and 360 days. The ideal user flow should… --- ## [Cross canister query calls](https://forum.dfinity.org/t/cross-canister-query-calls/41138)
**Author:** [@aligatorr89](https://forum.dfinity.org/u/aligatorr89)\ **Replies:** 16\ **Last updated:** [April 1, 2025, 7:02am UTC](https://forum.dfinity.org/t/cross-canister-query-calls/41138 "2025-04-01T07:02:10Z")
How to do a cross canister query call ? For example I would like to check icrc1\_balance\_of to ledger canister from my canister. I tried to use ic\_cdk::call but it doesn’t work for normal queries, only for composite que… --- ## [Title: Error 503 When Deploying Canister – Asset Sync Failure](https://forum.dfinity.org/t/title-error-503-when-deploying-canister-asset-sync-failure/42174)
**Author:** [@herbertzap](https://forum.dfinity.org/u/herbertzap)\ **Replies:** 2\ **Last updated:** [March 13, 2025, 3:40pm UTC](https://forum.dfinity.org/t/title-error-503-when-deploying-canister-asset-sync-failure/42174 "2025-03-13T15:40:58Z")
Question: Hi everyone, I’m encountering an issue when trying to deploy my canister on the Internet Computer. The deployment fails with a 503 Service Unavailable error during the asset synchronization process. Here’s th… --- ## [Icrc metadata inconsistency](https://forum.dfinity.org/t/icrc-metadata-inconsistency/40793)
**Author:** [@aligatorr89](https://forum.dfinity.org/u/aligatorr89)\ **Replies:** 9\ **Last updated:** [February 13, 2025, 10:13am UTC](https://forum.dfinity.org/t/icrc-metadata-inconsistency/40793 "2025-02-13T10:13:54Z")
Hi community! We are trying to integrate ICRC wallets on Taggr. Recently icrc1\_metadata has been changed on some ledger canisters. It’s missing logo parameter. Do you know how to find logo, for example on CHAT ledger c… --- ## [Call\_with\_payment in Pocket IC](https://forum.dfinity.org/t/call-with-payment-in-pocket-ic/40652)
**Author:** [@AlexEmets](https://forum.dfinity.org/u/AlexEmets)\ **Replies:** 8\ **Last updated:** [January 30, 2025, 7:35am UTC](https://forum.dfinity.org/t/call-with-payment-in-pocket-ic/40652 "2025-01-30T07:35:35Z")
Using call\_with\_payment in Pocket IC Integration Tests I have a canister with a subscribe method (Candid update call) that requires payment from subscribers to top up their balances and access the canister’s functionalit… --- ## [Some questions about the timer in ic-cdk](https://forum.dfinity.org/t/some-questions-about-the-timer-in-ic-cdk/17475)
**Author:** [@flyq](https://forum.dfinity.org/u/flyq)\ **Replies:** 2\ **Last updated:** [December 24, 2024, 2:33am UTC](https://forum.dfinity.org/t/some-questions-about-the-timer-in-ic-cdk/17475 "2024-12-24T02:33:57Z")
I found that there are three main functions in the timer mod, set\_timer, set\_timer\_interval, clear\_timer. Among them, set\_timer is used to set a one-time task, set\_timer\_interval is used to set a periodic task, and clear… --- ## [How to create a CDK for Pharo Smalltalk?](https://forum.dfinity.org/t/how-to-create-a-cdk-for-pharo-smalltalk/38634)
**Author:** [@chicoary](https://forum.dfinity.org/u/chicoary)\ **Replies:** 1\ **Last updated:** [December 9, 2024, 11:21am UTC](https://forum.dfinity.org/t/how-to-create-a-cdk-for-pharo-smalltalk/38634 "2024-12-09T11:21:56Z")
I’ve seen that dynamic languages like Javascript and Python already have a CDK. Where can I find the instructions to do the same for Pharo Smalltalk? I thought about a transpiler (See link below) for Motoko but I don’t k… --- ## [VS Code ICP Extension](https://forum.dfinity.org/t/vs-code-icp-extension/34747)
**Author:** [@SE7EN](https://forum.dfinity.org/u/SE7EN)\ **Replies:** 28\ **Last updated:** [November 26, 2024, 12:32pm UTC](https://forum.dfinity.org/t/vs-code-icp-extension/34747 "2024-11-26T12:32:22Z")
Hi, We received funding from the Dfinity Foundation to develop a VS Code extension for ICP. One of the deliverables for Milestone 2 is to publish the extension on the VS Code Marketplace. Before doing so, however, we w… --- ## [JWS validation in the VC flow (prepare\_credential function)](https://forum.dfinity.org/t/jws-validation-in-the-vc-flow-prepare-credential-function/34613)
**Author:** [@Jonath-z](https://forum.dfinity.org/u/Jonath-z)\ **Replies:** 13\ **Last updated:** [September 10, 2024, 5:28pm UTC](https://forum.dfinity.org/t/jws-validation-in-the-vc-flow-prepare-credential-function/34613 "2024-09-10T17:28:29Z")
Hi all, In the VC specification; prepare\_credential should validate the JWS, I’m using JavaScript/TypeScript; so far I can decode the JWS; and have access to all the component inside: the signature; the headers, etc. Ho… --- ## [Javascript/Typescript vc\_utils package](https://forum.dfinity.org/t/javascript-typescript-vc-utils-package/34525)
**Author:** [@Jonath-z](https://forum.dfinity.org/u/Jonath-z)\ **Replies:** 5\ **Last updated:** [August 29, 2024, 9:29am UTC](https://forum.dfinity.org/t/javascript-typescript-vc-utils-package/34525 "2024-08-29T09:29:00Z")
Is is possible to have vc\_utils as JS/TS lib? The one for only verifying the age is not really usefull --- ## [@dfinity/verifiable-credentials SDK](https://forum.dfinity.org/t/dfinity-verifiable-credentials-sdk/34486)
**Author:** [@Jonath-z](https://forum.dfinity.org/u/Jonath-z)\ **Replies:** 3\ **Last updated:** [August 26, 2024, 2:39pm UTC](https://forum.dfinity.org/t/dfinity-verifiable-credentials-sdk/34486 "2024-08-26T14:39:57Z")
Hi, I’m trying to test my VC issuer using @dfinity/verifiable-credentials on frontend, however the SDK does not seem to sends request on localhost, instead it’s sending the request to the ICP mainnet. This is my how … --- ## [I keep getting this error when i try to start the replica, tried to kill the instance several times but to no avail](https://forum.dfinity.org/t/i-keep-getting-this-error-when-i-try-to-start-the-replica-tried-to-kill-the-instance-several-times-but-to-no-avail/33799)
**Author:** [@Pgabby97](https://forum.dfinity.org/u/Pgabby97)\ **Replies:** 0\ **Last updated:** [August 1, 2024, 9:14pm UTC](https://forum.dfinity.org/t/i-keep-getting-this-error-when-i-try-to-start-the-replica-tried-to-kill-the-instance-several-times-but-to-no-avail/33799 "2024-08-01T21:14:59Z")
pgabby@DESKTOP-VEHTE9C:~/medcare$ dfx start Running dfx start for version 0.22.0 Using the default configuration for the local shared network. Error: Failed to get frontend address. Caused by: Failed to find reusable… --- ## [Common pip packages on the python CDK](https://forum.dfinity.org/t/common-pip-packages-on-the-python-cdk/33201)
**Author:** [@pdutra145](https://forum.dfinity.org/u/pdutra145)\ **Replies:** 5\ **Last updated:** [July 17, 2024, 8:36pm UTC](https://forum.dfinity.org/t/common-pip-packages-on-the-python-cdk/33201 "2024-07-17T20:36:18Z")
Is it possible to develop canisters that are able to use pandas dataframes that have the values fetched through some API and make some computations with the dataframe values (even though the canister public shared functi… --- ## [Websocket set up error(Witness != Tree in ic-certification)](https://forum.dfinity.org/t/websocket-set-up-error-witness-tree-in-ic-certification/33162)
**Author:** [@krunal](https://forum.dfinity.org/u/krunal)\ **Replies:** 3\ **Last updated:** [July 16, 2024, 12:36pm UTC](https://forum.dfinity.org/t/websocket-set-up-error-witness-tree-in-ic-certification/33162 "2024-07-16T12:36:49Z")
I am trying to use websocket in my website. I referred ic-websocket-cdk-mo and ic-websockets-chat-mo. But getting error. My code : class wsServices { constructor() { this.ws = null; } init({ \_i… --- ## [Error in websocket setup on ic](https://forum.dfinity.org/t/error-in-websocket-setup-on-ic/32551)
**Author:** [@Peacexoom](https://forum.dfinity.org/u/Peacexoom)\ **Replies:** 0\ **Last updated:** [July 1, 2024, 8:22am UTC](https://forum.dfinity.org/t/error-in-websocket-setup-on-ic/32551 "2024-07-01T08:22:48Z")
Hi all, I’m currently working with WebSocket and encountering an issue. The error I’m receiving is: \[certification\] Witness != Tree passed in ic-certification Error: \[onWsMessage\] Certificate validation failed at Rk.… --- ## [Problem in Websocket set up](https://forum.dfinity.org/t/problem-in-websocket-set-up/31403)
**Author:** [@krunal](https://forum.dfinity.org/u/krunal)\ **Replies:** 9\ **Last updated:** [June 19, 2024, 6:59pm UTC](https://forum.dfinity.org/t/problem-in-websocket-set-up/31403 "2024-06-19T18:59:41Z")
I am trying to implement authenticated call in websocket. I referred the ic-websocket-cdk-mo repo. import IcWebSocket, { generateRandomIdentity } from "ic-websocket-js"; import { canisterId, pingpong\_backend } from "..… [Next page](https://forum.dfinity.org/c/developers/cdk/36.md?page=1)