# Developers **URL:** https://forum.klever.org/c/kleverchain/developers/9.md [Latest](https://forum.klever.org/latest.md) · [Categories](https://forum.klever.org/categories.md) · [Tags](https://forum.klever.org/tags.md) --- ## [About the Developers category](https://forum.klever.org/t/about-the-developers-category/19)
**Author:** [@Duka](https://forum.klever.org/u/Duka)\ **Replies:** 0
This category is for developers and anyone interested in the more technical / code aspect of KleverChain. Dive into the world of Web 3 with KleverChain! Learn how to use, develop, deploy, and optimize Klever Smart Contr… --- ## [How to fetch a contract's current WASM code by address?](https://forum.klever.org/t/how-to-fetch-a-contracts-current-wasm-code-by-address/4501)
**Author:** [@janill](https://forum.klever.org/u/janill)\ **Replies:** 2\ **Last updated:** [August 5, 2026, 9:27pm UTC](https://forum.klever.org/t/how-to-fetch-a-contracts-current-wasm-code-by-address/4501 "2026-08-05T21:27:33Z")
Hey everyone! I’m building a smart contract on Klever and want to let users verify that the deployed bytecode matches the open-source repository. My plan is straightforward: rebuild the contract reproducibly, hash the r… --- ## [Burning a Token by Sending It to a Dead Wallet Address](https://forum.klever.org/t/burning-a-token-by-sending-it-to-a-dead-wallet-address/4253)
**Author:** [@luistorres](https://forum.klever.org/u/luistorres)\ **Replies:** 4\ **Last updated:** [August 3, 2026, 1:26pm UTC](https://forum.klever.org/t/burning-a-token-by-sending-it-to-a-dead-wallet-address/4253 "2026-08-03T13:26:08Z")
Is it possible to burn a token via a smart contract by sending it to an invalid wallet, for example: klv0000000000000burn0000000000 ? For tokens with a mint function that cannot be changed, is there any risk that tokens… --- ## [Wallet Connect for Klever DApps](https://forum.klever.org/t/wallet-connect-for-klever-dapps/3301)
**Author:** [@XPort\_App](https://forum.klever.org/u/XPort_App)\ **Replies:** 4\ **Last updated:** [July 14, 2026, 6:15pm UTC](https://forum.klever.org/t/wallet-connect-for-klever-dapps/3301 "2026-07-14T18:15:59Z")
Hey KleverWallet Team! I previously asked @Bruno\_Campos about the possibility of implementing a Wallet Connect feature similar to TON Connect, enabling Klever transactions to be approved directly within a web app withou… --- ## [I built a Klever balance lookup from a single prompt using the Connect MCP](https://forum.klever.org/t/i-built-a-klever-balance-lookup-from-a-single-prompt-using-the-connect-mcp/4443)
**Author:** [@Nicollas](https://forum.klever.org/u/Nicollas)\ **Replies:** 0\ **Last updated:** [June 3, 2026, 12:32pm UTC](https://forum.klever.org/t/i-built-a-klever-balance-lookup-from-a-single-prompt-using-the-connect-mcp/4443 "2026-06-03T12:32:30Z")
I’ve been using the Klever Connect MCP — the AI knowledge server for the @klever/connect JS/TS SDK — and wanted to share a small demo, because the result was cleaner than I expected. Briefly, what it is: it’s not for wr… --- ## [Kleverscan Token Descriptions](https://forum.klever.org/t/kleverscan-token-descriptions/3930)
**Author:** [@XPort\_App](https://forum.klever.org/u/XPort_App)\ **Replies:** 21\ **Last updated:** [May 14, 2026, 8:52pm UTC](https://forum.klever.org/t/kleverscan-token-descriptions/3930 "2026-05-14T20:52:37Z")
Hey KleverScan team! We’d like to use the token descriptions shown on KleverScan, but currently CORS restrictions are preventing us from accessing that data programmatically. Is there any way around this? Would really… --- ## [About events and logs in Smart Contracts](https://forum.klever.org/t/about-events-and-logs-in-smart-contracts/4370)
**Author:** [@janill](https://forum.klever.org/u/janill)\ **Replies:** 1\ **Last updated:** [April 20, 2026, 6:23pm UTC](https://forum.klever.org/t/about-events-and-logs-in-smart-contracts/4370 "2026-04-20T18:23:27Z")
Hey everyone! I’m currently trying out the KVM capabilities and I can’t have a grasp on one topic. What are indexed arguments in events? And why can’t I add more than one non-indexed data-argument to my event? Explaina… --- ## [How to Set Up Klever Smart Contracts on Windows (Step-by-Step Guide)](https://forum.klever.org/t/how-to-set-up-klever-smart-contracts-on-windows-step-by-step-guide/3657)
**Author:** [@Nicollas](https://forum.klever.org/u/Nicollas)\ **Replies:** 10\ **Last updated:** [April 15, 2026, 3:30pm UTC](https://forum.klever.org/t/how-to-set-up-klever-smart-contracts-on-windows-step-by-step-guide/3657 "2026-04-15T15:30:44Z")
Hello, dear Windows users! It’s finally time to start developing Smart Contracts right from your Windows machine! :tada: This tutorial is designed to help you set up your development environment. After following these s… --- ## [Trading Bot / Klever Wallet & Blockchain](https://forum.klever.org/t/trading-bot-klever-wallet-blockchain/4367)
**Author:** [@Peter\_Shaw](https://forum.klever.org/u/Peter_Shaw)\ **Replies:** 3\ **Last updated:** [April 13, 2026, 6:55pm UTC](https://forum.klever.org/t/trading-bot-klever-wallet-blockchain/4367 "2026-04-13T18:55:19Z")
l was trying to create a trading bot that interacts with DEX’s. Quite good progress - but is there a recommended transaction structure that will accept and recognise the request, as l have quite a few failed transactions… --- ## [KleverChain IDE Extension for Visual Studio Code: Installation Guide](https://forum.klever.org/t/kleverchain-ide-extension-for-visual-studio-code-installation-guide/1093)
**Author:** [@Duka](https://forum.klever.org/u/Duka)\ **Replies:** 81\ **Last updated:** [April 13, 2026, 6:06pm UTC](https://forum.klever.org/t/kleverchain-ide-extension-for-visual-studio-code-installation-guide/1093 "2026-04-13T18:06:47Z")
The Kleverchain IDE Extension for Visual Studio Code is a powerful tool that allows developers to write, build, and debug smart contracts for the Klever blockchain. The extension provides a comprehensive development e… --- ## [How to build and broadcast a SmartContract (type 63) transaction using @klever/sdk-node?](https://forum.klever.org/t/how-to-build-and-broadcast-a-smartcontract-type-63-transaction-using-klever-sdk-node/4296)
**Author:** [@Jose\_Luis\_Latas](https://forum.klever.org/u/Jose_Luis_Latas)\ **Replies:** 2\ **Last updated:** [February 23, 2026, 1:08pm UTC](https://forum.klever.org/t/how-to-build-and-broadcast-a-smartcontract-type-63-transaction-using-klever-sdk-node/4296 "2026-02-23T13:08:43Z")
Hello, I’m using @klever/sdk-node to build transactions in a Node.js backend. Transfer transactions (type 0) work perfectly with account.buildTransaction(): const unsignedTx = await account.buildTransaction(\[{ payloa… --- ## ["invalid receiver address" error when using buildTransaction with extension v1.0](https://forum.klever.org/t/invalid-receiver-address-error-when-using-buildtransaction-with-extension-v1-0/4239)
**Author:** [@Jose\_Luis\_Latas](https://forum.klever.org/u/Jose_Luis_Latas)\ **Replies:** 1\ **Last updated:** [February 3, 2026, 10:23pm UTC](https://forum.klever.org/t/invalid-receiver-address-error-when-using-buildtransaction-with-extension-v1-0/4239 "2026-02-03T22:23:23Z")
Hi, I’m trying to create transactions from a web app using window.kleverWeb.buildTransaction() on Testnet, but I always get the error “invalid receiver address”. Setup: Extension version: 1.0 Provider: { api: 'ht… --- ## [From Congestion to Scale: Extending Ethereum’s Horizon with the Klever Bridge & KVM](https://forum.klever.org/t/from-congestion-to-scale-extending-ethereum-s-horizon-with-the-klever-bridge-kvm/4207)
**Author:** [@Duka](https://forum.klever.org/u/Duka)\ **Replies:** 1\ **Last updated:** [January 27, 2026, 6:43am UTC](https://forum.klever.org/t/from-congestion-to-scale-extending-ethereum-s-horizon-with-the-klever-bridge-kvm/4207 "2026-01-27T06:43:42Z")
The Multi-Chain Reality We live in a multi-chain world. While Ethereum has undeniably established itself as the global settlement layer and the home of smart contract innovation, it faces the well-known trilemma of s… --- ## [Smart Contract Function Executes Successfully But Does Not Transfer Tokens](https://forum.klever.org/t/smart-contract-function-executes-successfully-but-does-not-transfer-tokens/4155)
**Author:** [@luistorres](https://forum.klever.org/u/luistorres)\ **Replies:** 4\ **Last updated:** [December 5, 2025, 9:23am UTC](https://forum.klever.org/t/smart-contract-function-executes-successfully-but-does-not-transfer-tokens/4155 "2025-12-05T09:23:48Z")
Hello, this is Luis from Digiko! I am experiencing an issue with a smart contract function on Klever mainnet and need assistance understanding what might be wrong. Background I have deployed a DEX contract at address:… --- ## [How to update swagger at our own Indexer](https://forum.klever.org/t/how-to-update-swagger-at-our-own-indexer/4146)
**Author:** [@Maik](https://forum.klever.org/u/Maik)\ **Replies:** 2\ **Last updated:** [November 27, 2025, 12:09pm UTC](https://forum.klever.org/t/how-to-update-swagger-at-our-own-indexer/4146 "2025-11-27T12:09:42Z")
There are 2 points in question, which we would like to adjust to our needs. Update of the server URL adjusting of the präfix in front of the parameters to get “/v1.0/” like at the official proxy Swagger --- ## [Error including metadata in an SFT (testnet)](https://forum.klever.org/t/error-including-metadata-in-an-sft-testnet/4143)
**Author:** [@Jose\_Luis\_Latas](https://forum.klever.org/u/Jose_Luis_Latas)\ **Replies:** 4\ **Last updated:** [November 25, 2025, 8:46pm UTC](https://forum.klever.org/t/error-including-metadata-in-an-sft-testnet/4143 "2025-11-25T20:46:12Z")
Hello, On TestNet, I created an SFT ( Asset - PUKR-30R2 | Klever Explorer ), and when I try to add the metadata, I’m getting the error “AssetTypeInvalid” ( Transaction - fe68a...390b5 | Klever Explorer ). I’m not sure … --- ## [Rest API output "code: "internal\_issue""](https://forum.klever.org/t/rest-api-output-code-internal-issue/4144)
**Author:** [@Maik](https://forum.klever.org/u/Maik)\ **Replies:** 4\ **Last updated:** [November 25, 2025, 7:47pm UTC](https://forum.klever.org/t/rest-api-output-code-internal-issue/4144 "2025-11-25T19:47:57Z")
The indexer produces an error message while retrieving data. Maybe someone can point out how to check such issues and how to fix this, besides, why this error happens. https://api.mainnet.klever.org/v1.0/address/klv1py… --- ## [How to test and use the websocket on Indexer?](https://forum.klever.org/t/how-to-test-and-use-the-websocket-on-indexer/4140)
**Author:** [@Maik](https://forum.klever.org/u/Maik)\ **Replies:** 5\ **Last updated:** [November 25, 2025, 3:08pm UTC](https://forum.klever.org/t/how-to-test-and-use-the-websocket-on-indexer/4140 "2025-11-25T15:08:10Z")
I’ve just set up an Indexer, which is running fine and Kibana shows that data getting collected. Now I wanted to test the websocket with Postman via ws://MY\_IP:8080/subscribe Connection is successfully in Postman, but … --- ## [Websocket/Rest API via SSL?](https://forum.klever.org/t/websocket-rest-api-via-ssl/4141)
**Author:** [@Maik](https://forum.klever.org/u/Maik)\ **Replies:** 0\ **Last updated:** [November 22, 2025, 11:38am UTC](https://forum.klever.org/t/websocket-rest-api-via-ssl/4141 "2025-11-22T11:38:55Z")
The Klever documention just describes the “standard” setup to run the Indexer and to get the websocket running. This all happens with insecure connections, without SSL. I just wanted to start the Node with certificates,… --- ## [Bug or Feature?: Peerlist contains different blskeys for master and fallback nodes](https://forum.klever.org/t/bug-or-feature-peerlist-contains-different-blskeys-for-master-and-fallback-nodes/4045)
**Author:** [@CryptoJaeger](https://forum.klever.org/u/CryptoJaeger)\ **Replies:** 3\ **Last updated:** [November 7, 2025, 11:58am UTC](https://forum.klever.org/t/bug-or-feature-peerlist-contains-different-blskeys-for-master-and-fallback-nodes/4045 "2025-11-07T11:58:20Z")
Hello @fbsobreira @blockchain guys @Duka I have another question. I’ve been trying to fix my node registration over the last few days and have come across a strange phenomenon. The BLSKey of the masternode and the BLSK… --- ## [Testnet back-up](https://forum.klever.org/t/testnet-back-up/4047)
**Author:** [@SAME1](https://forum.klever.org/u/SAME1)\ **Replies:** 7\ **Last updated:** [October 15, 2025, 1:42pm UTC](https://forum.klever.org/t/testnet-back-up/4047 "2025-10-15T13:42:09Z")
Hi team, I’m trying to use my own indexer node with elastic search on testnet. Everything is running fine but the back-up mentioned in the documentation is not working. Can you provide a new one? This is the doc: https:… --- ## [Klever Web SDK ESM blocked by CORS — we’re self-hosting now. Did the CDN/config change?](https://forum.klever.org/t/klever-web-sdk-esm-blocked-by-cors-we-re-self-hosting-now-did-the-cdn-config-change/4034)
**Author:** [@Andreas\_Hennersdorf](https://forum.klever.org/u/Andreas_Hennersdorf)\ **Replies:** 4\ **Last updated:** [September 23, 2025, 3:00pm UTC](https://forum.klever.org/t/klever-web-sdk-esm-blocked-by-cors-we-re-self-hosting-now-did-the-cdn-config-change/4034 "2025-09-23T15:00:42Z")
Hi Klever team, we’ve been loading the ESM build of the Klever Web SDK from sdk.kleverscan.org for a while. Starting today, browsers began blocking it with a CORS error, even though nothing changed on our side. Our sit… --- ## [Peerslist elected validators, displayed as jailed](https://forum.klever.org/t/peerslist-elected-validators-displayed-as-jailed/4030)
**Author:** [@CryptoJaeger](https://forum.klever.org/u/CryptoJaeger)\ **Replies:** 2\ **Last updated:** [September 16, 2025, 6:58pm UTC](https://forum.klever.org/t/peerslist-elected-validators-displayed-as-jailed/4030 "2025-09-16T18:58:28Z")
@fbsobreira @Maik @MathijsBok We both recently discussed that Klever Radar sometimes provides incorrect information about missing blocks for jailed validators. (This is not the case for every jail.) My question is: Wi… --- ## [Klever Unveils API Access to Crucial KDA Metrics](https://forum.klever.org/t/klever-unveils-api-access-to-crucial-kda-metrics/1100)
**Author:** [@Duka](https://forum.klever.org/u/Duka)\ **Replies:** 4\ **Last updated:** [September 16, 2025, 6:51pm UTC](https://forum.klever.org/t/klever-unveils-api-access-to-crucial-kda-metrics/1100 "2025-09-16T18:51:30Z")
Attention Developers! We are thrilled to announce the release of an API that provides individual access to key KDA metrics, including: Total Supply: https://klever-stats.services.klever.io/api.dws?q=totalcoins&kda=… --- ## [I have a question about the smart contract on the testnet](https://forum.klever.org/t/i-have-a-question-about-the-smart-contract-on-the-testnet/4015)
**Author:** [@YusaAung](https://forum.klever.org/u/YusaAung)\ **Replies:** 4\ **Last updated:** [September 12, 2025, 11:23am UTC](https://forum.klever.org/t/i-have-a-question-about-the-smart-contract-on-the-testnet/4015 "2025-09-12T11:23:30Z")
I’m currently building a testnet to introduce KVM, but I am having trouble with the deployment page from Smart Contract. I’m currently trying to deploy using the Chrome browser on MacOS, and after dragging a WASM fil… --- ## [First outgoing transaction from SDK-created account fails until activated in Wallet](https://forum.klever.org/t/first-outgoing-transaction-from-sdk-created-account-fails-until-activated-in-wallet/4011)
**Author:** [@Sovkosov\_Ignat](https://forum.klever.org/u/Sovkosov_Ignat)\ **Replies:** 13\ **Last updated:** [September 9, 2025, 12:40am UTC](https://forum.klever.org/t/first-outgoing-transaction-from-sdk-created-account-fails-until-activated-in-wallet/4011 "2025-09-09T00:40:06Z")
Hi Klever Team, We’ve encountered an issue with new accounts created via @klever/sdk-node. Symptom: Addresses created with new Account() can successfully receive incoming transactions, but the first outgoing transacti… --- ## [Incorrect links in swagger ui](https://forum.klever.org/t/incorrect-links-in-swagger-ui/3992)
**Author:** [@CryptoJaeger](https://forum.klever.org/u/CryptoJaeger)\ **Replies:** 2\ **Last updated:** [August 18, 2025, 1:35pm UTC](https://forum.klever.org/t/incorrect-links-in-swagger-ui/3992 "2025-08-18T13:35:45Z")
In the Swagger UI of the NODE API, the links still point to klever.finance and not to klever.org. @Duka --- ## [Clarification on Current API Rate Limits](https://forum.klever.org/t/clarification-on-current-api-rate-limits/3978)
**Author:** [@XPort\_App](https://forum.klever.org/u/XPort_App)\ **Replies:** 1\ **Last updated:** [August 8, 2025, 2:31pm UTC](https://forum.klever.org/t/clarification-on-current-api-rate-limits/3978 "2025-08-08T14:31:26Z")
Hey Klever Team, I’ve noticed a recent change in API behavior, potentially indicating a reduction in request limits or the application of IP-based restrictions. Could you please clarify the current rate limits and any … --- ## [PendingTxs testnet](https://forum.klever.org/t/pendingtxs-testnet/3962)
**Author:** [@SAME1](https://forum.klever.org/u/SAME1)\ **Replies:** 3\ **Last updated:** [July 30, 2025, 5:26pm UTC](https://forum.klever.org/t/pendingtxs-testnet/3962 "2025-07-30T17:26:01Z")
When using the klever websdk it seems my txs aren’t boardcasted to the testnet anymore. Can someone help me with this? { “data”: { “firstPendingNonce”: 409, “nonce”: 388, “txPending”: 25 }, “error”: “”, “code”: “… --- ## [Token data and kleverscan API issue](https://forum.klever.org/t/token-data-and-kleverscan-api-issue/3933)
**Author:** [@C\_K](https://forum.klever.org/u/C_K)\ **Replies:** 7\ **Last updated:** [July 22, 2025, 6:21pm UTC](https://forum.klever.org/t/token-data-and-kleverscan-api-issue/3933 "2025-07-22T18:21:14Z")
below are my console logs when my app try’s connecting to the kleverscan API this is recent I had it working without issue not to long ago. Am i missing something Extension availability check: {hasKleverWeb: false, win… [Next page](https://forum.klever.org/c/kleverchain/developers/9.md?page=1)