Universal Resolution

ensips/x.md

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+---
+description: A universal entrypoint for resolving ENS names.
+contributors:
+  - taytems.eth
+ensip:
+  created: "2024-10-14"
+  status: draft
+---
+
+# ENSIP-X: Universal Resolution
+
+## Abstract
+
+This ENSIP defines a universal entrypoint for resolving ENS names, via an interface (i.e the UniversalResolver).
+
+## Motivation
+
+The process of resolving ENS names traditionally requires multiple onchain calls, and that an implementing developer has in-depth knowledge of ENS.
+This is becoming more prevalent over time, especially with the introduction of wildcard resolution (ENSIP-10), and more recently cross-chain reverse resolution (ENSIP-19).
+These factors mean there is a relatively high burden to implement ENS, with high latency, and a large amount of developer hours to spend to understand and implement the correct resolution process.
+
+Given these factors, there are significant incentives for incorrect/incomplete ENS implementations, or implementations that do not rely on Ethereum as the source of truth.
+
+Beyond the implementation burdens, maintaining many resolution implementations means that any change to ENS resolution that an ENSIP might provide becomes a challenging task to propagate amongst the ecosystem, and as such significantly limits the growth of the ENS protocol with novel concepts.
+
+As a solution for these challenges, this specification proposes an interface that allows universally resolving any ENS name, or any reverse name.
+
+## Specification
+
+A compliant implementation of the UniversalResolver must implement the following interface:
+
+```solidity
+interface IUniversalResolver {
+  function resolve(bytes calldata name, bytes calldata data) external view returns (bytes memory result, address resolver);
+  function reverse(bytes calldata lookupAddress, uint256 coinType) external view returns (string memory name, address resolver, address reverseResolver);
+}
+```
+
+### resolve
+
+The `resolve` function should be used by any ENS client as a complete replacement for offchain resolution methods.
+
+Similar to that of ENSIP-10, this function takes two parameters:
+
+- `name`: The DNS-encoded name to resolve
+- `data`: The encoded calldata for a resolver function
+
+If intending to resolve multiple requests, the `data` parameter can be encoded via the following multicall interface:
+
+```solidity
+interface IMulticallable {
+  function multicall(bytes[] calldata data) external view returns (bytes[] memory results);
+}
+```
+
+Decoding the result of a multicall should be done by using the output of the same interface.
+Errors are returned in the results array of a multicall, and can be checked with `len(result) % 32 == 4`.
+
+Example of a multicall:
+
+```typescript
+function getData(name: string) {
+  const encodedMulticallData = encodeFunctionData({
+    name: "multicall",
+    args: [
+      [
+        encodeFunctionData({
+          name: "addr",
+          args: [namehash(name)],
+        }),
+        encodeFunctionData({
+          name: "text",
+          args: [namehash(name), "url"],
+        }),
+      ],
+    ],
+  });
+  const [encodedMulticallResult, resolverAddress] =
+    await universalResolver.resolve(dnsEncodeName(name), encodedMulticallData);
+  const decodedMulticallResults = decodeFunctionResult({
+    name: "multicall",
+    data: encodedMulticallResult,
+  });
+
+  decodedMulticallResults.forEach((result) => {
+    if (result.length % 32 === 4) {
+      throw new Error("Error in result");
+    }
+  });
+
+  return {
+    results: decodedMulticallResults,
+    resolverAddress,
+  };
+}
+```
+
+The output of this function is:
+
+- `bytes`: The data returned by the resolver
+- `address`: The address of the resolver that resolved the name
+
+### reverse
+
+The `reverse` function can be used by any ENS client as a complete replacement for offchain reverse name resolution methods.
+
+This function takes two parameters:
+
+- `lookupAddress`: The address to resolve the name for, in **encoded** form.
+- `coinType`: The coin type to resolve the name for, as defined by ENSIP-9 and ENSIP-11.
+
+The output of this function is:
+
+- `name`: The verified reverse resolved name.
+- `resolver`: The address of the resolver that resolved the `addr` record for the name (i.e. forward verification).
+- `reverseResolver`: The address of the resolver that resolved the `name` record.
+
+## Backwards Compatibility
+
+The UniversalResolver is intended to be a complete replacement for offchain resolution methods, and should be used as such.
+
+## Security Considerations
+
+None.
+
+## Copyright
+
+Copyright and related rights waived via [CC0](https://creativecommons.org/publicdomain/zero/1.0/).