# How to add public setURI on ERC1155? **URL:** \ **Category:** Contracts\ **Created:** [November 19, 2020, 2:19pm UTC](https://forum.openzeppelin.com/t/how-to-add-public-seturi-on-erc1155/4675 "2020-11-19T14:19:58Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Eibriel](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/eibriel/32/3597_2.png) [@Eibriel](https://forum.openzeppelin.com/u/Eibriel)\ **Post date:** [November 19, 2020, 2:19pm UTC](https://forum.openzeppelin.com/t/how-to-add-public-seturi-on-erc1155/4675/1 "2020-11-19T14:19:58Z")
Hi! I would like to have `setURI` public on my ERC1155, I’m using `ERC1155PresetMinterPauserUpgradeable`. I added the following function, but not sure if something is missing, and what to do with the emit requiring an additional parameter for the ID. ```auto function setURI(string memory newuri) public { require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "SoapPunkCollectibles: must have admin role to change uri"); emit URI(newuri, 0); _setURI(newuri); } ``` Doing something like this, adding the ID parameter to setURI just for the emit would be fine? ```auto function setURI(string memory newuri, uint256 id) public { require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "SoapPunkCollectibles: must have admin role to change uri"); emit URI(newuri, id); _setURI(newuri); } ``` Thank you! ---
**Author:** ![abcoathup](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/abcoathup/32/415_2.png) [@abcoathup](https://forum.openzeppelin.com/u/abcoathup)\ **Post date:** [November 20, 2020, 8:20am UTC](https://forum.openzeppelin.com/t/how-to-add-public-seturi-on-erc1155/4675/2 "2020-11-20T08:20:21Z")
Hi @Eibriel, Welcome to the community 👋 The OpenZeppelin Contracts ERC1155 implementation uses a single `URI` for the entire contract. See the following example: [Create an ERC1155](https://forum.openzeppelin.com/t/create-an-erc1155/4433). According to the EIP (see: [https://eips.ethereum.org/EIPS/eip-1155#metadata](https://eips.ethereum.org/EIPS/eip-1155#metadata)): > - _Changes_ to the URI MUST emit the `URI` event if the change can be expressed with an event (i.e. it isn’t dynamic/programmatic). > - An implementation MAY emit the `URI` event during a mint operation but it is NOT mandatory. An observer MAY fetch the metadata uri at mint time from the `uri` function if it was not emitted. > - The `uri` function SHOULD be used to retrieve values if no event was emitted. > - The `uri` function MUST return the same value as the latest event for an `_id` if it was emitted. I interpret this as changing the `uri` for the contract would require emitting the event for each token ID. Though I recommend reading the EIP on this detail. ```auto event URI(string _value, uint256 indexed _id); ``` Do you want to use a different `uri` per token ID? Under what circumstances would you want to change the `uri`? ---
**Author:** ![Eibriel](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/eibriel/32/3597_2.png) [@Eibriel](https://forum.openzeppelin.com/u/Eibriel)\ **Post date:** [November 20, 2020, 1:58pm UTC](https://forum.openzeppelin.com/t/how-to-add-public-seturi-on-erc1155/4675/3 "2020-11-20T13:58:20Z")
Thank you for the response. Then the second version, the one that requires a call to `setURI` for each ID seems appropriate for my project (maybe I could add an extra function allowing to set the `uri` for an array of IDs, emitting several events in one call). I’m building a small game that will have an organic growth, instead of having a predefined clear roadmap. Server migrations and web domain changes are a possibility in the future and I would like to avoid having to upgrade the contract. ---
**Author:** ![abcoathup](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/abcoathup/32/415_2.png) [@abcoathup](https://forum.openzeppelin.com/u/abcoathup)\ **Post date:** [November 20, 2020, 7:55pm UTC](https://forum.openzeppelin.com/t/how-to-add-public-seturi-on-erc1155/4675/4 "2020-11-20T19:55:57Z")
Hi @Eibriel, My thoughts would be to keep it simple. Use a domain name that is future proof and update the DNS if you need to change servers/hosts/implementation. That way you don’t need to change the URI and emit events when you do so. ---
**Author:** ![dagr](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/dagr/32/8188_2.png) [@dagr](https://forum.openzeppelin.com/u/dagr)\ **Post date:** [August 12, 2021, 5:17pm UTC](https://forum.openzeppelin.com/t/how-to-add-public-seturi-on-erc1155/4675/5 "2021-08-12T17:17:59Z")
What would you suggest when using IPFS? If I have a directory that contains all token metadata and a new token id is added later on, the hash of the directory would change. I could publish an IPNS entry and set it as the URI once, but the IPNS entry is created using a centralized private key. You could also use a mutable file storage with IPFS, but I feel like this is even more centralized. ---
**Author:** ![skyone.nanshan](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/skyone.nanshan/32/12224_2.png) [@skyone.nanshan](https://forum.openzeppelin.com/u/skyone.nanshan)\ **Post date:** [January 13, 2022, 7:47am UTC](https://forum.openzeppelin.com/t/how-to-add-public-seturi-on-erc1155/4675/6 "2022-01-13T07:47:05Z")
Yep, I want to ask Can I set a URL for a specific ID? For example , this? make sense? ```auto function setURI(string memory newuri, uint256 id) public { require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "SoapPunkCollectibles: must have admin role to change uri"); emit URI(newuri, id); _setURI(newuri,id); } ``` ---
**Author:** ![Amxx](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/amxx/32/668_2.png) [@Amxx](https://forum.openzeppelin.com/u/Amxx)\ **Post date:** [January 13, 2022, 9:06am UTC](https://forum.openzeppelin.com/t/how-to-add-public-seturi-on-erc1155/4675/7 "2022-01-13T09:06:42Z")
The ERC1155 standard is designed with only one URI for all token ids. See [the "metadata" section](https://eips.ethereum.org/EIPS/eip-1155#metadata) of reference document ---
**Author:** ![skyone.nanshan](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/skyone.nanshan/32/12224_2.png) [@skyone.nanshan](https://forum.openzeppelin.com/u/skyone.nanshan)\ **Post date:** [January 14, 2022, 8:35am UTC](https://forum.openzeppelin.com/t/how-to-add-public-seturi-on-erc1155/4675/8 "2022-01-14T08:35:16Z")
So,,, there is no way to set single ID for now , right?