Update README.md

README.md

@@ -1,2 +1,83 @@
-# IP-to-ASN-and-Whois
+# IP-to-ASN Lookup API (fast hehe)
-IP to ASN and Basic Whois with Country APi without Rate Limits
+
+This API allows you to lookup the **ASN**, **country**, and **provider name** for a given IPv4 or IPv6 address.
+
+## Base URL
+
+```
+https://cdn.t-w.dev/whois?ip={IP}
+```
+
+---
+
+## Request
+
+### Method
+
+* **GET** or **POST**
+
+### Parameters
+
+| Name | Type   | Required | Description                   |
+| ---- | ------ | -------- | ----------------------------- |
+| ip   | string | Yes      | IPv4 or IPv6 address to query |
+
+---
+
+## Response
+
+### Success (200)
+
+| Field       | Type   | Description                        |
+| ----------- | ------ | ---------------------------------- |
+| ip          | string | The queried IP address             |
+| asn         | string | Autonomous System Number           |
+| country     | string | 2-letter country code of the ASN   |
+| description | string | Cleaned provider name (normalized) |
+
+**Example:**
+
+```json
+{
+  "ip": "8.8.8.8",
+  "asn": "15169",
+  "country": "US",
+  "description": "Google"
+}
+```
+
+### Error (400+)
+
+| Field | Type   | Description                |
+| ----- | ------ | -------------------------- |
+| error | string | Description of the problem |
+
+**Examples:**
+
+```json
+{ "error": "Missing 'ip' parameter" }
+```
+
+```json
+{ "error": "Invalid IP address" }
+```
+
+```json
+{ "error": "ASN not found for given IP" }
+```
+
+---
+
+## API Flow
+
+```mermaid
+flowchart TD
+    A[Client Request] --> B{IP parameter provided?}
+    B -- No --> C[Return Error: Missing 'ip' parameter]
+    B -- Yes --> D{IP valid?}
+    D -- No --> E[Return Error: Invalid IP address]
+    D -- Yes --> F[Lookup IP in ASN database]
+    F --> G{ASN found?}
+    G -- Yes --> H[Return JSON with ip, asn, country, description]
+    G -- No --> I[Return Error: ASN not found]
+```