--- eip: 831 title: URI Format for Ethereum description: A way of creating Ethereum URIs for various use-cases. author: ligi (@ligi) discussions-to: https://ethereum-magicians.org/t/eip-831-uri-format-for-ethereum/10105 status: Stagnant type: Standards Track category: ERC created: 2018-01-15 requires: 67, 681 --- ## Abstract URIs embedded in QR-codes, hyperlinks in web-pages, emails or chat messages provide for robust cross-application signaling between very loosely coupled applications. A standardized URI format allows for instant invocation of the user's preferred wallet application. ## Specification ### Syntax Ethereum URIs contain "ethereum" or "eth" in their schema (protocol) part and are constructed as follows: request = "eth" [ "ereum" ] ":" [ prefix "-" ] payload prefix = STRING payload = STRING ### Semantics `prefix` is optional and defines the use-case for this URI. If no prefix is given: "pay-" is assumed to be concise and ensure backward compatibility to [EIP-67](./eip-67.md). When the prefix is omitted, the payload must start with `0x`. Also prefixes must not start with `0x`. So starting with `0x` can be used as a clear signal that there is no prefix. `payload` is mandatory and the content depends on the prefix. Structuring of the content is defined in the ERC for the specific use-case and not in the scope of this document. One example is [EIP-681](./eip-681) for the pay- prefix. ## Rationale The need for this ERC emerged when refining EIP-681. We need a container that does not carry the weight of the use-cases. EIP-67 was the first attempt on defining Ethereum-URIs. This ERC tries to keep backward compatibility and not break existing things. This means EIP-67 URIs should still be valid and readable. Only if the prefix feature is used, EIP-67 parsers might break. No way was seen to avoid this and innovate on the same time. This is also the reason this open prefix approach was chosen to being able to adopt to future use-cases and not block the whole "ethereum:" scheme for a limited set of use-cases that existed at the time of writing this. ## Security Considerations There are no known security considerations at this time. ## Copyright Copyright and related rights waived via [CC0](../LICENSE.md).