# JavaScript **URL:** https://forum.dfinity.org/c/developers/javascript/31.md [Latest](https://forum.dfinity.org/latest.md) · [Categories](https://forum.dfinity.org/categories.md) · [Tags](https://forum.dfinity.org/tags.md) --- ## [About the JavaScript category](https://forum.dfinity.org/t/about-the-javascript-category/9487)
**Author:** [@anon74414410](https://forum.dfinity.org/u/anon74414410)\ **Replies:** 1\ **Last updated:** [July 1, 2022, 9:17pm UTC](https://forum.dfinity.org/t/about-the-javascript-category/9487 "2022-07-01T21:17:10Z")
This is a topic to help people tag and identify discussions about JavaScript and TypeScript development. Feel free to discuss general JS/TS development questions, or topics specific to the Internet Computer JavaScript ag… --- ## [🚀 IC Reactor v3: The Production-Ready Data Fetching Library for the Internet Computer](https://forum.dfinity.org/t/ic-reactor-v3-the-production-ready-data-fetching-library-for-the-internet-computer/64034)
**Author:** [@b3hr4d](https://forum.dfinity.org/u/b3hr4d)\ **Replies:** 4\ **Last updated:** [February 25, 2026, 10:02am UTC](https://forum.dfinity.org/t/ic-reactor-v3-the-production-ready-data-fetching-library-for-the-internet-computer/64034 "2026-02-25T10:02:05Z")
Hi everyone! :waving\_hand: Following our beta announcement, I am thrilled to announce that IC Reactor v3 is now officially stable and released! :rocket: If you are building frontends on the Internet Computer, you know … --- ## [SSL certificate for www.mobilebloodtest.com not issuing after multiple weeks](https://forum.dfinity.org/t/ssl-certificate-for-www-mobilebloodtest-com-not-issuing-after-multiple-weeks/63622)
**Author:** [@AIisKillingMe](https://forum.dfinity.org/u/AIisKillingMe)\ **Replies:** 1\ **Last updated:** [January 30, 2026, 10:12pm UTC](https://forum.dfinity.org/t/ssl-certificate-for-www-mobilebloodtest-com-not-issuing-after-multiple-weeks/63622 "2026-01-30T22:12:01Z")
What type of topic is this? Support Discussion | Support | Bug Report Hello team the caffeine AI told me to ask this, My domain “www mobilebloodtest com” is using a CNAME to “ic0 app”. DNS is stable but the SSL certif… --- ## [ICP JavaScript SDK Core v5.0.0 is released!](https://forum.dfinity.org/t/icp-javascript-sdk-core-v5-0-0-is-released/61675)
**Author:** [@ilbert](https://forum.dfinity.org/u/ilbert)\ **Replies:** 9\ **Last updated:** [January 12, 2026, 4:56pm UTC](https://forum.dfinity.org/t/icp-javascript-sdk-core-v5-0-0-is-released/61675 "2026-01-12T16:56:48Z")
We have released v5.0.0 of the ICP JavaScript SDK Core library. This major release focuses on consolidating the @icp-sdk/core package and improving it. For detailed upgrading instructions and information about the new f… --- ## [\[v3 Beta Announcement\] IC Reactor: The "Missing" Data-Fetching Library for Internet Computer](https://forum.dfinity.org/t/v3-beta-announcement-ic-reactor-the-missing-data-fetching-library-for-internet-computer/62164)
**Author:** [@b3hr4d](https://forum.dfinity.org/u/b3hr4d)\ **Replies:** 11\ **Last updated:** [January 7, 2026, 4:46pm UTC](https://forum.dfinity.org/t/v3-beta-announcement-ic-reactor-the-missing-data-fetching-library-for-internet-computer/62164 "2026-01-07T16:46:16Z")
Hi everyone! :waving\_hand: I’m excited to announce the v3 Beta of IC Reactor — a modern, type-safe library designed to solve the “frontend boilerplate” when building on the Internet Computer. If you’ve ever found yours… --- ## [ICP JavaScript SDK v4.0.0 is released!](https://forum.dfinity.org/t/icp-javascript-sdk-v4-0-0-is-released/55915)
**Author:** [@ilbert](https://forum.dfinity.org/u/ilbert)\ **Replies:** 21\ **Last updated:** [November 24, 2025, 10:09am UTC](https://forum.dfinity.org/t/icp-javascript-sdk-v4-0-0-is-released/55915 "2025-11-24T10:09:14Z")
We have released v4.0.0 of the ICP JavaScript SDK libraries. This major release introduces the new unified @icp-sdk/core package, consolidating multiple @dfinity/\* packages into a single solution. What’s New The only ch… --- ## [Error: The certificate contains a delegation that does not include the canister aaaaa-aa in the canister\_ranges field](https://forum.dfinity.org/t/error-the-certificate-contains-a-delegation-that-does-not-include-the-canister-aaaaa-aa-in-the-canister-ranges-field/57766)
**Author:** [@Huygon764](https://forum.dfinity.org/u/Huygon764)\ **Replies:** 26\ **Last updated:** [November 18, 2025, 2:51am UTC](https://forum.dfinity.org/t/error-the-certificate-contains-a-delegation-that-does-not-include-the-canister-aaaaa-aa-in-the-canister-ranges-field/57766 "2025-11-18T02:51:48Z")
Hi guys, I’m trying to create a canister from the backend (NestJS) and install\_code into it. But I’m getting this error: The certificate contains a delegation that does not include the canister aaaaa-aa in the canister\_… --- ## [Cannot find module '@icp-sdk/core/principal' or its corresponding type declarations](https://forum.dfinity.org/t/cannot-find-module-icp-sdk-core-principal-or-its-corresponding-type-declarations/59759)
**Author:** [@peterparker](https://forum.dfinity.org/u/peterparker)\ **Replies:** 3\ **Last updated:** [November 12, 2025, 9:19am UTC](https://forum.dfinity.org/t/cannot-find-module-icp-sdk-core-principal-or-its-corresponding-type-declarations/59759 "2025-11-12T09:19:07Z")
No stress, I know the answer! :wink: I’m sharing this post for “documentation” purposes, as I faced it again and, in case any developers in the ecosystem encounter the following error on the forum after migrating to @ic… --- ## [ICP JavaScript SDK v3.0.0 is released!](https://forum.dfinity.org/t/icp-javascript-sdk-v3-0-0-is-released/53679)
**Author:** [@ilbert](https://forum.dfinity.org/u/ilbert)\ **Replies:** 10\ **Last updated:** [November 5, 2025, 4:04pm UTC](https://forum.dfinity.org/t/icp-javascript-sdk-v3-0-0-is-released/53679 "2025-11-05T16:04:14Z")
We have released v3.0.0 of the ICP JavaScript SDK libraries. This is a major release that introduces significant refactoring, API improvements, and breaking changes. Among the key improvements, this release eliminates B… --- ## [Issues with @dfinity/agent polling](https://forum.dfinity.org/t/issues-with-dfinity-agent-polling/59177)
**Author:** [@mzibara](https://forum.dfinity.org/u/mzibara)\ **Replies:** 1\ **Last updated:** [October 21, 2025, 10:33am UTC](https://forum.dfinity.org/t/issues-with-dfinity-agent-polling/59177 "2025-10-21T10:33:41Z")
Hey! Plug Team has encountered issue with @dfinity/agent: 3.2.0 Most of the requests via Actor.createActor fail with Request timed out after 30000msec, however this is error thrown much faster than 30 seconds. Interes… --- ## [ICP JS SDK Bindgen is released!](https://forum.dfinity.org/t/icp-js-sdk-bindgen-is-released/58712)
**Author:** [@ilbert](https://forum.dfinity.org/u/ilbert)\ **Replies:** 0\ **Last updated:** [October 9, 2025, 10:26am UTC](https://forum.dfinity.org/t/icp-js-sdk-bindgen-is-released/58712 "2025-10-09T10:26:38Z")
We have released the new @icp-sdk/bindgen package, which allows you to generate modern and idiomatic TypeScript bindings for Candid canister interfaces. Today we released v0.1. There can be breaking changes even in futu… --- ## [🧪 Announcing PicJS: TypeScript/JavaScript support for PocketIC!](https://forum.dfinity.org/t/announcing-picjs-typescript-javascript-support-for-pocketic/24479)
**Author:** [@NathanosDev](https://forum.dfinity.org/u/NathanosDev)\ **Replies:** 167\ **Last updated:** [September 15, 2025, 5:22pm UTC](https://forum.dfinity.org/t/announcing-picjs-typescript-javascript-support-for-pocketic/24479 "2025-09-15T17:22:12Z")
I’m happy to announce PicJS, a canister testing library with TypeScript/JavaScript support for PocketIC! PicJS allows you to write integration tests for your canisters using your favorite JavaScript test runners and run… --- ## [Error while trying to run IDL.encode on values around 1.8×10^308 or larger](https://forum.dfinity.org/t/error-while-trying-to-run-idl-encode-on-values-around-1-8x10-308-or-larger/32924)
**Author:** [@bdemann](https://forum.dfinity.org/u/bdemann)\ **Replies:** 3\ **Last updated:** [July 29, 2025, 4:28pm UTC](https://forum.dfinity.org/t/error-while-trying-to-run-idl-encode-on-values-around-1-8x10-308-or-larger/32924 "2025-07-29T16:28:48Z")
What type of topic is this? Bug Report I am having some problems encoding large bigints This works IDL.encode( \[IDL.Nat\], \[ 170\_000\_000\_000\_000\_000\_000\_000\_000\_000\_000\_000\_000\_000\_000\_000\_000\_000\_000\_… --- ## [Agent-JS Beta Release - v3.0.0-beta.0](https://forum.dfinity.org/t/agent-js-beta-release-v3-0-0-beta-0/50854)
**Author:** [@anon74414410](https://forum.dfinity.org/u/anon74414410)\ **Replies:** 7\ **Last updated:** [July 22, 2025, 12:02pm UTC](https://forum.dfinity.org/t/agent-js-beta-release-v3-0-0-beta-0/50854 "2025-07-22T12:02:00Z")
Big changes coming to Agent JS! We’d love for you to test them out before they go live. You can install and test the beta versions with npm install --save @dfinity/agent@beta or npm install --save @dfinity/agent@3.0.… --- ## [Callback on every block](https://forum.dfinity.org/t/callback-on-every-block/51804)
**Author:** [@qwertytrewq](https://forum.dfinity.org/u/qwertytrewq)\ **Replies:** 0\ **Last updated:** [June 29, 2025, 9:07am UTC](https://forum.dfinity.org/t/callback-on-every-block/51804 "2025-06-29T09:07:48Z")
I want a JavaScript callback to be called every time when a new block is produced. How? --- ## [Create Identity from Principal ID or \_delegations](https://forum.dfinity.org/t/create-identity-from-principal-id-or-delegations/33977)
**Author:** [@putuwaw](https://forum.dfinity.org/u/putuwaw)\ **Replies:** 2\ **Last updated:** [June 26, 2025, 2:48am UTC](https://forum.dfinity.org/t/create-identity-from-principal-id-or-delegations/33977 "2025-06-26T02:48:32Z")
Support | Question I’m trying to call a canister from my backend using the identity that the user obtained from the frontend. Is it possible to recreate this identity using the principal ID or from a \_delegation by stri… --- ## [vetKeys BLS12-381 G2 transport\_public\_key](https://forum.dfinity.org/t/vetkeys-bls12-381-g2-transport-public-key/48526)
**Author:** [@dev88](https://forum.dfinity.org/u/dev88)\ **Replies:** 6\ **Last updated:** [June 9, 2025, 1:22pm UTC](https://forum.dfinity.org/t/vetkeys-bls12-381-g2-transport-public-key/48526 "2025-06-09T13:22:16Z")
Guys I would appreciate some help. I have wasted days trying everything to implement the .wasm thing for the vetkd to create transport key to pass to rust canister for encrypted generation. I am in creactjs with craco. I… --- ## [Insufficient balance when pushing a tx signed by a canister - ETH](https://forum.dfinity.org/t/insufficient-balance-when-pushing-a-tx-signed-by-a-canister-eth/45947)
**Author:** [@andredevjs](https://forum.dfinity.org/u/andredevjs)\ **Replies:** 4\ **Last updated:** [May 8, 2025, 4:20pm UTC](https://forum.dfinity.org/t/insufficient-balance-when-pushing-a-tx-signed-by-a-canister-eth/45947 "2025-05-08T16:20:30Z")
What type of topic is this? Support Hello everyone, I’m working on a larger project and need to get this piece working. Specifically, I’m retrieving the public key from the canister, deriving the corresponding Ethereu… --- ## [📢 pic-js has moved to the DFINITY GitHub organization!](https://forum.dfinity.org/t/pic-js-has-moved-to-the-dfinity-github-organization/43792)
**Author:** [@NathanosDev](https://forum.dfinity.org/u/NathanosDev)\ **Replies:** 3\ **Last updated:** [April 15, 2025, 12:27pm UTC](https://forum.dfinity.org/t/pic-js-has-moved-to-the-dfinity-github-organization/43792 "2025-04-15T12:27:59Z")
Nathan from the SDK Team here and today I’m excited to announce that pic-js has officially migrated to the DFINITY GitHub organization! :tada: This means that going forward, pic-js will be maintained by the SDK team in D… --- ## [Watermark error when trying to access the canister via agent-js](https://forum.dfinity.org/t/watermark-error-when-trying-to-access-the-canister-via-agent-js/43821)
**Author:** [@let4be](https://forum.dfinity.org/u/let4be)\ **Replies:** 9\ **Last updated:** [April 15, 2025, 9:44am UTC](https://forum.dfinity.org/t/watermark-error-when-trying-to-access-the-canister-via-agent-js/43821 "2025-04-15T09:44:21Z")
Constant error when using agent-js, canister inaccessible with 75% of calls failing with Error while making call: Timestamp failed to pass the watermark after retrying the configured 3 times. We cannot guarantee the int… --- ## [Frontend canister deployment error](https://forum.dfinity.org/t/frontend-canister-deployment-error/43642)
**Author:** [@sam-thetutor](https://forum.dfinity.org/u/sam-thetutor)\ **Replies:** 5\ **Last updated:** [April 11, 2025, 9:14am UTC](https://forum.dfinity.org/t/frontend-canister-deployment-error/43642 "2025-04-11T09:14:44Z")
I have a frontend canister that is already deployed on the mainnet. When I try to deploy it again after making changes, I get the following error. What could be the issue? --- ## [Registered Custom Domain Not Available](https://forum.dfinity.org/t/registered-custom-domain-not-available/43482)
**Author:** [@Delpen9](https://forum.dfinity.org/u/Delpen9)\ **Replies:** 10\ **Last updated:** [April 11, 2025, 8:08am UTC](https://forum.dfinity.org/t/registered-custom-domain-not-available/43482 "2025-04-11T08:08:33Z")
I am trying to setup my custom domain for my website. I followed all the steps necessary to get my custom domain registered: {“name”:“idmempres.info”,“canister”:“ctyk5-niaaa-aaaan-qzwza-cai”,“state”:“Available”} To ge… --- ## [Automatic ii login](https://forum.dfinity.org/t/automatic-ii-login/43319)
**Author:** [@shreyamahajan456](https://forum.dfinity.org/u/shreyamahajan456)\ **Replies:** 11\ **Last updated:** [April 3, 2025, 10:24am UTC](https://forum.dfinity.org/t/automatic-ii-login/43319 "2025-04-03T10:24:23Z")
can we do like automatic ii login ? Like if i have deployed two links one for mainnet one for other mainnet . i want when i first login in mainnet link and when i click on toggle it show some thing in url , as in when w… --- ## [Hosting Node.js backend using Fastify and Typescript on ICP](https://forum.dfinity.org/t/hosting-node-js-backend-using-fastify-and-typescript-on-icp/43300)
**Author:** [@kaumudisoman](https://forum.dfinity.org/u/kaumudisoman)\ **Replies:** 1\ **Last updated:** [April 3, 2025, 6:28am UTC](https://forum.dfinity.org/t/hosting-node-js-backend-using-fastify-and-typescript-on-icp/43300 "2025-04-03T06:28:38Z")
Our company’s website is currently hosted on AWS, with the backend built using Node.js, Fastify, and TypeScript. We are planning to migrate our backend to the Internet Computer (ICP) and would appreciate guidance on the … --- ## [Convert IDL classes (RecClass VariantClass RecordClass etc) into candid](https://forum.dfinity.org/t/convert-idl-classes-recclass-variantclass-recordclass-etc-into-candid/23006)
**Author:** [@bdemann](https://forum.dfinity.org/u/bdemann)\ **Replies:** 11\ **Last updated:** [March 31, 2025, 11:40pm UTC](https://forum.dfinity.org/t/convert-idl-classes-recclass-variantclass-recordclass-etc-into-candid/23006 "2025-03-31T23:40:42Z")
What type of topic is this? Support I have been using the @dfinity/candid npm package to encode and decode javascript values into candid values for Azle. It’s going great! From here I want to be able to convert those c… --- ## [Transaction id generation](https://forum.dfinity.org/t/transaction-id-generation/43130)
**Author:** [@adarsh312](https://forum.dfinity.org/u/adarsh312)\ **Replies:** 0\ **Last updated:** [March 29, 2025, 9:59am UTC](https://forum.dfinity.org/t/transaction-id-generation/43130 "2025-03-29T09:59:05Z")
What type of topic is this? Discussion | Support I want to create a transaction id for the given transaction, i am getting 3f41f7df29fe43812ac704e4c09c9bc4fd08944f35cdbe4eb6a626bc140dc0af but the actual tx id is f8d31… --- ## [Wasm problem for vetkeys usage](https://forum.dfinity.org/t/wasm-problem-for-vetkeys-usage/43050)
**Author:** [@MykhailoIvchenko](https://forum.dfinity.org/u/MykhailoIvchenko)\ **Replies:** 0\ **Last updated:** [March 27, 2025, 4:39pm UTC](https://forum.dfinity.org/t/wasm-problem-for-vetkeys-usage/43050 "2025-03-27T16:39:49Z")
Hi guys! I’ve implemented an application with vetKeys usage. Here is GitHub repository: MykhailoIvchenko/password-manager-dapp The application uses React + Vite for the frontend part. I copied the files from the vetkd… --- ## [How to validate a Principal build with fromUint8Array is legit?](https://forum.dfinity.org/t/how-to-validate-a-principal-build-with-fromuint8array-is-legit/42335)
**Author:** [@peterparker](https://forum.dfinity.org/u/peterparker)\ **Replies:** 4\ **Last updated:** [March 17, 2025, 10:11am UTC](https://forum.dfinity.org/t/how-to-validate-a-principal-build-with-fromuint8array-is-legit/42335 "2025-03-17T10:11:01Z")
I either forgot about it or never had to do it before, but how do you validate that a Principal created using Principal.fromUint8Array is actually a valid Principal? Asking because, for example, Principal.fromUint8Array… --- ## [vetKD: loading WASM failed](https://forum.dfinity.org/t/vetkd-loading-wasm-failed/42058)
**Author:** [@Baiumka](https://forum.dfinity.org/u/Baiumka)\ **Replies:** 1\ **Last updated:** [March 10, 2025, 10:02am UTC](https://forum.dfinity.org/t/vetkd-loading-wasm-failed/42058 "2025-03-10T10:02:47Z")
Hi! I am learning VetKD module now. I have trouble with using it. When i try to get key const tsk = new vetkd.TransportSecretKey(seed); i got error smth like “vetkd is not inited”. According to example i try to init mo… --- ## [ICP-ChainVault: Unlock Bitcoin Liquidity on Internet Computer](https://forum.dfinity.org/t/icp-chainvault-unlock-bitcoin-liquidity-on-internet-computer/41810)
**Author:** [@samarabdelhameed](https://forum.dfinity.org/u/samarabdelhameed)\ **Replies:** 0\ **Last updated:** [March 3, 2025, 7:51am UTC](https://forum.dfinity.org/t/icp-chainvault-unlock-bitcoin-liquidity-on-internet-computer/41810 "2025-03-03T07:51:38Z")
ICP-ChainVault: Unlocking Bitcoin Liquidity on Internet Computer :gem\_stone: :rocket: Project Highlights ICP-ChainVault is a DeFi platform built on the Internet Computer (ICP) that enables Bitcoin holders to unlock insta… [Next page](https://forum.dfinity.org/c/developers/javascript/31.md?page=1)