# 🛠️ Builders **URL:** https://forum.flow.com/c/builders/37.md [Latest](https://forum.flow.com/latest.md) · [Categories](https://forum.flow.com/categories.md) · [Tags](https://forum.flow.com/tags.md) --- ## [About the 🛠️ Builders category](https://forum.flow.com/t/about-the-builders-category/2875)
**Author:** [@pgpg](https://forum.flow.com/u/pgpg)\ **Replies:** 0
Builders is for anyone who wants to build on Flow, contribute to building Flow, discuss features of Cadence, the Flow Blockchain and its libraries, or generally just lurke and follow what’s going on at a technical level! … --- ## [Upgrade coming soon to FungibleToken on Mainnet](https://forum.flow.com/t/upgrade-coming-soon-to-fungibletoken-on-mainnet/7594)
**Author:** [@flowjosh](https://forum.flow.com/u/flowjosh)\ **Replies:** 1\ **Last updated:** [May 6, 2025, 6:13pm UTC](https://forum.flow.com/t/upgrade-coming-soon-to-fungibletoken-on-mainnet/7594 "2025-05-06T18:13:26Z")
The Flow team has a tentative plan to upgrade the FungibleToken smart contract on mainnet on May 6th, 2025. This is a non-breaking change to restore minor functionality that was lost after a recent Cadence upgrade. More … --- ## [Cadence Compilation](https://forum.flow.com/t/cadence-compilation/7060)
**Author:** [@supun](https://forum.flow.com/u/supun)\ **Replies:** 12\ **Last updated:** [February 11, 2025, 10:08pm UTC](https://forum.flow.com/t/cadence-compilation/7060 "2025-02-11T22:08:20Z")
Background Since its inception, Cadence language has come a long way, getting richer in features, safety, and usability day by day. The reference implementation of Cadence has been using an interpreter to execute program… --- ## [Updates to Cadence 1.0 Contract Staging](https://forum.flow.com/t/updates-to-cadence-1-0-contract-staging/5642)
**Author:** [@gio\_on\_flow](https://forum.flow.com/u/gio_on_flow)\ **Replies:** 6\ **Last updated:** [February 22, 2024, 6:33pm UTC](https://forum.flow.com/t/updates-to-cadence-1-0-contract-staging/5642 "2024-02-22T18:33:13Z")
Overview This post relates to the changes to the staging contract outlined in FLIP 179. While the mechanism outlined in that FLIP may be useful for the general purpose of coordinating contract updates, it was decided tha… --- ## [Accessing Collections in Cadence 1.0](https://forum.flow.com/t/accessing-collections-in-cadence-1-0/6485)
**Author:** [@rgne](https://forum.flow.com/u/rgne)\ **Replies:** 6\ **Last updated:** [September 30, 2024, 5:13pm UTC](https://forum.flow.com/t/accessing-collections-in-cadence-1-0/6485 "2024-09-30T17:13:59Z")
Hey Guys, I am trying to get the NFT data after the Cadence 1.0 upgrade. In Cadence 0.42 I could use the getCapability.borrow method to get a collection, and use that collection’s .borrowMomentNFT(id) to get the NFT, a… --- ## [How to create a verifiable signature](https://forum.flow.com/t/how-to-create-a-verifiable-signature/1552)
**Author:** [@avcd](https://forum.flow.com/u/avcd)\ **Replies:** 5\ **Last updated:** [September 16, 2024, 8:20pm UTC](https://forum.flow.com/t/how-to-create-a-verifiable-signature/1552 "2024-09-16T20:20:11Z")
I would like to create an ECDSA\_P256 signature in offchain and verify it in Cadence. So I have tried the following code using Node.js, but the result fails (false returns). Can you please tell me what is wrong with thi… --- ## [Programmable Oracle Infrastructure On Flow](https://forum.flow.com/t/programmable-oracle-infrastructure-on-flow/6465)
**Author:** [@Matt-SEDA](https://forum.flow.com/u/Matt-SEDA)\ **Replies:** 0\ **Last updated:** [September 5, 2024, 8:53am UTC](https://forum.flow.com/t/programmable-oracle-infrastructure-on-flow/6465 "2024-09-05T08:53:57Z")
To discuss development of Programmable Oracle programs on Flow. Using SEDA’s SDK, Flow devs can access any data type (public & private or any other network data sources) and deploy custom oracle feeds to suit any use ca… --- ## [Optimize Your Flow Development with GetBlock's Shared and Dedicated RPC Full Nodes](https://forum.flow.com/t/optimize-your-flow-development-with-getblocks-shared-and-dedicated-rpc-full-nodes/6118)
**Author:** [@0xpcGB](https://forum.flow.com/u/0xpcGB)\ **Replies:** 1\ **Last updated:** [June 25, 2024, 4:09am UTC](https://forum.flow.com/t/optimize-your-flow-development-with-getblocks-shared-and-dedicated-rpc-full-nodes/6118 "2024-06-25T04:09:49Z")
Hello Flow Developers! :wave: Wish to start building on Flow or enhance your Flow dApps but don’t want to waste your time and funds on running and maintaining your own Flow full node? We have the solution! GetBlock is h… --- ## [Upgrade coming to Flow Service Account Smart contract to track non-updated Cadence 1.0 user contracts](https://forum.flow.com/t/upgrade-coming-to-flow-service-account-smart-contract-to-track-non-updated-cadence-1-0-user-contracts/6131)
**Author:** [@vishal](https://forum.flow.com/u/vishal)\ **Replies:** 0\ **Last updated:** [June 3, 2024, 9:56pm UTC](https://forum.flow.com/t/upgrade-coming-to-flow-service-account-smart-contract-to-track-non-updated-cadence-1-0-user-contracts/6131 "2024-06-03T21:56:48Z")
The Service Account smart contract on mainnet will be updated next week on Tuesday, June 11th by the service account committee. The update will add the checkDependencies function to the contract in preparation for the C… --- ## [Reducing the default maximum script execution effort on the execution node to 9999 computation units](https://forum.flow.com/t/reducing-the-default-maximum-script-execution-effort-on-the-execution-node-to-9999-computation-units/6130)
**Author:** [@vishal](https://forum.flow.com/u/vishal)\ **Replies:** 2\ **Last updated:** [June 3, 2024, 7:34am UTC](https://forum.flow.com/t/reducing-the-default-maximum-script-execution-effort-on-the-execution-node-to-9999-computation-units/6130 "2024-06-03T07:34:14Z")
Scripts are a light-weight method to query chain data. Scripts, unlike transactions, can only read chain data and not modify it. Also unlike a transaction, script do not require any transaction fees. For more information… --- ## [Protocol Version Upgrade Mechanisms Discussion](https://forum.flow.com/t/protocol-version-upgrade-mechanisms-discussion/5717)
**Author:** [@flowjordan](https://forum.flow.com/u/flowjordan)\ **Replies:** 4\ **Last updated:** [May 24, 2024, 6:55pm UTC](https://forum.flow.com/t/protocol-version-upgrade-mechanisms-discussion/5717 "2024-05-24T18:55:26Z")
Context The Core Protocol BFT team is working on a mechanism to upgrade the Protocol State without requiring a spork. The goal of this post is to briefly describe Flow’s existing version upgrade systems (spork, height-co… --- ## [Dynamic Protocol State as building block for Byzantine Fault Tolerance \[BFT\] and an autonomously-operating Flow-network](https://forum.flow.com/t/dynamic-protocol-state-as-building-block-for-byzantine-fault-tolerance-bft-and-an-autonomously-operating-flow-network/4906)
**Author:** [@AlexTheArchitect](https://forum.flow.com/u/AlexTheArchitect)\ **Replies:** 3\ **Last updated:** [January 12, 2024, 12:48am UTC](https://forum.flow.com/t/dynamic-protocol-state-as-building-block-for-byzantine-fault-tolerance-bft-and-an-autonomously-operating-flow-network/4906 "2024-01-12T00:48:16Z")
The core-protocol team is starting the work on ‘Flow’s Dynamic Protocol State’. In a nutshell, this work is a necessary premise for the Flow network to autonomously defend itself against malicious nodes within the networ… --- ## [EVM Equivalence on Flow: Proposal and Path Forward](https://forum.flow.com/t/evm-equivalence-on-flow-proposal-and-path-forward/5478)
**Author:** [@jeromep](https://forum.flow.com/u/jeromep)\ **Replies:** 3\ **Last updated:** [May 8, 2024, 10:08pm UTC](https://forum.flow.com/t/evm-equivalence-on-flow-proposal-and-path-forward/5478 "2024-05-08T22:08:26Z")
As we continue the effort to bring EVM Equivalence to Flow, we must discuss why this is important to the Flow network. Flow has a novel approach to many core aspects of a blockchain, the multi-node architecture, state st… --- ## [Update on Cadence 1.0](https://forum.flow.com/t/update-on-cadence-1-0/5197)
**Author:** [@bastian](https://forum.flow.com/u/bastian)\ **Replies:** 9\ **Last updated:** [May 6, 2024, 10:16pm UTC](https://forum.flow.com/t/update-on-cadence-1-0/5197 "2024-05-06T22:16:28Z")
Updates Dec 13th, 2023: We have now published the plan to release Cadence 1.0 - please have a look at this forum post: Cadence 1.0 Upgrade Plan Dec 20th, 2023: We have released preview release. Find the updated install… --- ## [Upgrade coming to the Randomness History Smart contract](https://forum.flow.com/t/upgrade-coming-to-the-randomness-history-smart-contract/5903)
**Author:** [@tarak.by](https://forum.flow.com/u/tarak.by)\ **Replies:** 2\ **Last updated:** [April 24, 2024, 3:41pm UTC](https://forum.flow.com/t/upgrade-coming-to-the-randomness-history-smart-contract/5903 "2024-04-24T15:41:03Z")
The Flow team has a tentative plan to upgrade the epoch smart contracts on mainnet on April 22nd. This is an upgrade that will not break any smart contracts or node software, and will fix an issue where past randomness s… --- ## [Questions about flow-EVM -- full EVM equivalence](https://forum.flow.com/t/questions-about-flow-evm-full-evm-equivalence/5784)
**Author:** [@michael](https://forum.flow.com/u/michael)\ **Replies:** 1\ **Last updated:** [April 1, 2024, 7:02pm UTC](https://forum.flow.com/t/questions-about-flow-evm-full-evm-equivalence/5784 "2024-04-01T19:02:12Z")
I read the following introduction about flow-EVM from here (Crescendo: Open for Builders). ======================================================================== EVM compatibility is not enough – achieve full EVM eq… --- ## [Flow DeFI does not support any cold wallet (ledger)](https://forum.flow.com/t/flow-defi-does-not-support-any-cold-wallet-ledger/5755)
**Author:** [@pwnage](https://forum.flow.com/u/pwnage)\ **Replies:** 0\ **Last updated:** [March 11, 2024, 11:15pm UTC](https://forum.flow.com/t/flow-defi-does-not-support-any-cold-wallet-ledger/5755 "2024-03-11T23:15:00Z")
There’s a significant issue stemming from Ledger’s lack of support for Flow arbitrary transactions. This limitation prevents us from utilizing Ledger outside of onFlow. Essentially, it means that whales, or large investo… --- ## [Streamlined Token Standards Proposal](https://forum.flow.com/t/streamlined-token-standards-proposal/3075)
**Author:** [@flowjosh](https://forum.flow.com/u/flowjosh)\ **Replies:** 55\ **Last updated:** [March 8, 2024, 7:10pm UTC](https://forum.flow.com/t/streamlined-token-standards-proposal/3075 "2024-03-08T19:10:23Z")
NOTE: The designs of the new standards have evolved significantly since this was originally posted, so many of the discussion points and code samples are out-of-date. Please refer to the FLIPs and PRs for the latest vers… --- ## [Is there a way to tell the difference between a EOA and a Dapp address based on the address (via any http methods)?](https://forum.flow.com/t/is-there-a-way-to-tell-the-difference-between-a-eoa-and-a-dapp-address-based-on-the-address-via-any-http-methods/5735)
**Author:** [@kaijiel24](https://forum.flow.com/u/kaijiel24)\ **Replies:** 0\ **Last updated:** [March 7, 2024, 3:55am UTC](https://forum.flow.com/t/is-there-a-way-to-tell-the-difference-between-a-eoa-and-a-dapp-address-based-on-the-address-via-any-http-methods/5735 "2024-03-07T03:55:46Z")
Is there a way to tell the difference between a EOA and a Dapp address based on the address (via any http methods)? --- ## [Breaking change coming to Flow Epoch Smart Contracts for Automatic Rewards](https://forum.flow.com/t/breaking-change-coming-to-flow-epoch-smart-contracts-for-automatic-rewards/4516)
**Author:** [@vishal](https://forum.flow.com/u/vishal)\ **Replies:** 9\ **Last updated:** [February 26, 2024, 4:28pm UTC](https://forum.flow.com/t/breaking-change-coming-to-flow-epoch-smart-contracts-for-automatic-rewards/4516 "2024-02-26T16:28:45Z")
The Flow team has tentative plans to enable automatic staking rewards payments on mainnet on April 27th after the next network spork on Wednesday, April 26, 2023. This will not break any smart contracts, but any software… --- ## [EVM on Flow – Beyond Solidity](https://forum.flow.com/t/evm-on-flow-beyond-solidity/5260)
**Author:** [@dete](https://forum.flow.com/u/dete)\ **Replies:** 7\ **Last updated:** [February 5, 2024, 9:14pm UTC](https://forum.flow.com/t/evm-on-flow-beyond-solidity/5260 "2024-02-05T21:14:37Z")
Flow was built from the ground up for mainstream-scale decentralized applications, and introduced a novel multirole architecture as well as Cadence, a resource-oriented programming language designed specifically for smar… --- ## [Cadence 1.0 Upgrade Plan](https://forum.flow.com/t/cadence-1-0-upgrade-plan/5477)
**Author:** [@Jan](https://forum.flow.com/u/Jan)\ **Replies:** 10\ **Last updated:** [January 26, 2024, 7:11pm UTC](https://forum.flow.com/t/cadence-1-0-upgrade-plan/5477 "2024-01-26T19:11:16Z")
Jan 19 2024: We have published an update to this post, please take a look here: Update on Cadence 1.0 Upgrade Plan Flow is releasing the biggest upgrade of Cadence since it launched in 2020 and this post explains ever… --- ## [Update on Cadence 1.0 Upgrade Plan](https://forum.flow.com/t/update-on-cadence-1-0-upgrade-plan/5597)
**Author:** [@Jan](https://forum.flow.com/u/Jan)\ **Replies:** 2\ **Last updated:** [January 22, 2024, 8:53am UTC](https://forum.flow.com/t/update-on-cadence-1-0-upgrade-plan/5597 "2024-01-22T08:53:41Z")
We have 2 updates to share with you and are looking for your thoughts and feedback. Update 1 Sumary The existing Crescendo test network will be used as the stable environment for new app development and general experime… --- ## [\[Cadence\] How to enforce that a user cannot own more than 1 resource](https://forum.flow.com/t/cadence-how-to-enforce-that-a-user-cannot-own-more-than-1-resource/5594)
**Author:** [@vali](https://forum.flow.com/u/vali)\ **Replies:** 0\ **Last updated:** [January 18, 2024, 8:36am UTC](https://forum.flow.com/t/cadence-how-to-enforce-that-a-user-cannot-own-more-than-1-resource/5594 "2024-01-18T08:36:25Z")
Hi, My contract C defines a resource of type T. Is there any design pattern to enforce the following requirement: An account cannot own more than 1 resource of type T from my contract C ? Specifically, I want to a… --- ## [Upgrade coming to Flow Epoch Smart contracts for security improvement](https://forum.flow.com/t/upgrade-coming-to-flow-epoch-smart-contracts-for-security-improvement/5443)
**Author:** [@tarak.by](https://forum.flow.com/u/tarak.by)\ **Replies:** 5\ **Last updated:** [January 10, 2024, 4:27pm UTC](https://forum.flow.com/t/upgrade-coming-to-flow-epoch-smart-contracts-for-security-improvement/5443 "2024-01-10T16:27:33Z")
The Flow team has a tentative plan to upgrade the epoch smart contracts on mainnet on Januray 3rd. This is a security improvement upgrade so it will not break any smart contracts, node software, but may cause a minor cha… --- ## [\[Cadence\] Storefront contract, and NFT data](https://forum.flow.com/t/cadence-storefront-contract-and-nft-data/5544)
**Author:** [@rgne](https://forum.flow.com/u/rgne)\ **Replies:** 2\ **Last updated:** [January 5, 2024, 5:28pm UTC](https://forum.flow.com/t/cadence-storefront-contract-and-nft-data/5544 "2024-01-05T17:28:47Z")
Hey guys, I am looking into NFTStorefront, and listing events (ListingAvailable, ListingCompleted). I can get the return values of the ListingAvailable event, for example. It contains the ListingResourceID, and the nftI… --- ## [Upgrade coming to Flow Epoch Smart contracts for performance and Access Node Slots](https://forum.flow.com/t/upgrade-coming-to-flow-epoch-smart-contracts-for-performance-and-access-node-slots/5397)
**Author:** [@flowjosh](https://forum.flow.com/u/flowjosh)\ **Replies:** 4\ **Last updated:** [December 7, 2023, 4:19pm UTC](https://forum.flow.com/t/upgrade-coming-to-flow-epoch-smart-contracts-for-performance-and-access-node-slots/5397 "2023-12-07T16:19:57Z")
The Flow team has tentative plans to upgrade the epoch smart contracts on mainnet on December 6th. This is mostly a performance upgrade so it will not break any smart contracts, node software, or event listeners, but the… --- ## [Why Cadence Only provide UnsafeRandom function instead of using random number generated by threshold signature?](https://forum.flow.com/t/why-cadence-only-provide-unsaferandom-function-instead-of-using-random-number-generated-by-threshold-signature/2009)
**Author:** [@lightningli](https://forum.flow.com/u/lightningli)\ **Replies:** 3\ **Last updated:** [November 4, 2023, 4:22am UTC](https://forum.flow.com/t/why-cadence-only-provide-unsaferandom-function-instead-of-using-random-number-generated-by-threshold-signature/2009 "2023-11-04T04:22:31Z")
Flow utilize threshold signature to generate random number used to pick random committee, why not expose this randomness to smart contract? Is there any considerations? --- ## [Building an Account Linking App with Magic Link](https://forum.flow.com/t/building-an-account-linking-app-with-magic-link/5307)
**Author:** [@jribbink](https://forum.flow.com/u/jribbink)\ **Replies:** 0\ **Last updated:** [October 20, 2023, 3:04pm UTC](https://forum.flow.com/t/building-an-account-linking-app-with-magic-link/5307 "2023-10-20T15:04:36Z")
One of the greatest challenges faced throughout the Web3 ecosystem is striking a balance between real ownership of digital assets and a seamless user experience. Historically, two main custodial models for private keys … --- ## [FLIP for Staged Contract Updates](https://forum.flow.com/t/flip-for-staged-contract-updates/5301)
**Author:** [@gio\_on\_flow](https://forum.flow.com/u/gio_on_flow)\ **Replies:** 0\ **Last updated:** [October 19, 2023, 7:26pm UTC](https://forum.flow.com/t/flip-for-staged-contract-updates/5301 "2023-10-19T19:26:45Z")
Quick last call for feedback on the Staged Contract Update FLIP. In case you’ve missed this proposal, here’s a TL;DR: This proposal outlines a mechanism for automated and efficient contract updates to take effect at or… [Next page](https://forum.flow.com/c/builders/37.md?page=1)