> For the complete documentation index, see [llms.txt](https://docs.space.id/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.space.id/developer-guide/web3-name-api-and-sdk/faq.md). # FAQ ### 1. What is the SPACE ID Web3 Name API? The Web3 Name API is a free HTTP API that helps developers integrate Web3 domains to their apps, efficiently and securely. The API provides: * Domain resolution: convert Web3 Domains into crypto addresses. * Reverse resolution: retrieve the primary Web3 Domain uniquely linked to the crypto address. ### 2. How do I access the API? You can access the API simply by sending requests to the endpoint URLs (as stated below) using the HTTP method GET. ### 3. How do I resolve a domain to an address using the API? Send a GET request: `https://nameapi.space.id/getAddress?domain=spaceid.bnb` Response: { "address": "0xb5932a6B7d50A966AEC6C74C97385412Fb497540"} ### 4. How do I reverse resolve an address to a domain? Send a GET request: `https://nameapi.space.id/getName?chainid=56&address=0xb5932a6B7d50A966AEC6C74C97385412Fb497540` Response: {"name": "spaceid.bnb"} ### 5. What is the SPACE ID Web3 Name SDK, and what's the difference between SDK and API? The SDK is a JavaScript/TypeScript library designed for client-side and backend integrations, allowing developers to directly query on-chain domain records inside their apps instead of handling API calls. Conversely, the API is a RESTful service that enables developers to access SPACE ID’s domain name resolution via HTTP requests, making it ideal for server-side applications and large-scale integrations. ### 6. How do I install the SDK and resolve domain names? Developers can install the Web3 Name SDK via: `npm install @web3-name-sdk/core viem@^1.20` And check the complete SDK documents here: