diff --git a/.github/assets/example/feeds.toml b/.github/assets/example/feeds.toml
index f241297..211bee9 100644
--- a/.github/assets/example/feeds.toml
+++ b/.github/assets/example/feeds.toml
@@ -13,8 +13,18 @@ xmlUrl = "https://feed2.com/rss"
 name = "list 2"
 
 [[lists.feeds]]
-title = "feed 1"
-xmlUrl = "https://feed1.com/rss"
+title = "bluesky"
+type = "bluesky"
+id = "username"
 [[lists.feeds]]
-title = "feed 2"
-xmlUrl = "https://feed2.com/rss"
+title = "note"
+type = "note"
+id = "username"
+[[lists.feeds]]
+title = "reddit"
+type = "reddit"
+id = "subreddit-name"
+[[lists.feeds]]
+title = "sizu.me"
+type = "sizu.me"
+id = "username"
diff --git a/.github/workflows/deps-update.yml b/.github/workflows/deps-update.yml
index b9f427c..13ddf87 100644
--- a/.github/workflows/deps-update.yml
+++ b/.github/workflows/deps-update.yml
@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: 🚚 Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29 # v4.1.6
         with:
           ref: dev
 
diff --git a/.github/workflows/gist-update.yml b/.github/workflows/gist-update.yml
index fd55f4b..d25e983 100644
--- a/.github/workflows/gist-update.yml
+++ b/.github/workflows/gist-update.yml
@@ -11,10 +11,10 @@ jobs:
 
     steps:
       - name: 🚚 Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29 # v4.1.6
 
       - name: 🦕 Setup Deno
-        uses: denoland/setup-deno@v1
+        uses: denoland/setup-deno@041b854f97b325bd60e53e9dc2de9cb9f9ac0cba # v1.1.4
         with:
           deno-version: v1.x
 
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1a6f646..289b65e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -21,10 +21,10 @@ jobs:
 
     steps:
       - name: 🚚 Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29 # v4.1.6
 
       - name: 🦕 Setup Deno
-        uses: denoland/setup-deno@v1
+        uses: denoland/setup-deno@041b854f97b325bd60e53e9dc2de9cb9f9ac0cba # v1.1.4
         with:
           deno-version: v1.x
 
@@ -41,6 +41,6 @@ jobs:
         run: deno check ./**/*.ts
 
       - name: ☂️ Upload Coverage
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@e28ff129e5465c2c0dcc6f003fc735cb6ae0c673 # v4.5.0
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
diff --git a/.gitignore b/.gitignore
index 0f06f34..c57ccee 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,4 @@
+/feeds.toml
+/outputs/
 /coverage
 /coverage.lcov
diff --git a/src/libs/convert.ts b/src/libs/convert.ts
index 3c59a27..485cac1 100644
--- a/src/libs/convert.ts
+++ b/src/libs/convert.ts
@@ -1,12 +1,15 @@
 import { stringify } from "@libs/xml";
 import { parse } from "@std/toml";
+import { transcodeXmlUrl } from "./sites.ts";
 import type { Feed, List, Lists, OPMLOutline } from "../types/mod.ts";
 
-export function convertToTOML(data: string): Lists {
+export function convertFromTOML(data: string): Lists {
   const lists: Lists = parse(data) as Lists;
   lists.lists.map((list: List) => {
     list.feeds.map((feed: Feed) => {
-      feed.xmlUrl = new URL(feed.xmlUrl);
+      feed.xmlUrl = feed.xmlUrl
+        ? new URL(feed.xmlUrl)
+        : transcodeXmlUrl(feed.title, feed.type, feed.id);
     });
   });
   return lists;
@@ -18,7 +21,9 @@ export function convertToOPML(list: List): string {
       return {
         "@title": feed.title,
         "@text": feed.title,
-        "@xmlUrl": feed.xmlUrl,
+        "@xmlUrl": feed.xmlUrl
+          ? new URL(feed.xmlUrl)
+          : transcodeXmlUrl(feed.title, feed.type, feed.id),
         "@type": "rss",
       };
     }),
diff --git a/src/libs/io.ts b/src/libs/io.ts
index 1edb027..cd4176c 100644
--- a/src/libs/io.ts
+++ b/src/libs/io.ts
@@ -1,12 +1,12 @@
 import { paramCase } from "@wok/case";
 import { format } from "@std/path";
-import { convertToOPML, convertToTOML } from "./convert.ts";
+import { convertFromTOML, convertToOPML } from "./convert.ts";
 import type { List, Lists } from "../types/mod.ts";
 
 export async function readTOML(file: string): Promise<Lists> {
   try {
     const data: string = await Deno.readTextFile(file);
-    return convertToTOML(data);
+    return convertFromTOML(data);
   } catch (error) {
     if (error instanceof Deno.errors.NotFound) {
       throw new Error(`File not found: "${file}"`);
diff --git a/src/libs/sites.ts b/src/libs/sites.ts
new file mode 100644
index 0000000..311b1a8
--- /dev/null
+++ b/src/libs/sites.ts
@@ -0,0 +1,23 @@
+import type { site } from "../types/mod.ts";
+
+const sites: site[] = [
+  { type: "bluesky", url: new URL("https://bsky.app/profile/{id}/rss") },
+  { type: "note", url: new URL("https://note.com/{id}/rss") },
+  { type: "reddit", url: new URL("https://www.reddit.com/r/{id}/.rss") },
+  { type: "sizu.me", url: new URL("https://sizu.me/{id}/rss") },
+];
+
+export function transcodeXmlUrl(
+  title: string,
+  type: string | undefined,
+  id: string | undefined,
+): URL {
+  if (!type) throw new Error(`Parameter not set: "type" of "${title}"`);
+  if (!id) throw new Error(`Parameter not set: "id" of "${title}"`);
+
+  const url: URL | undefined = sites
+    .find((site: site) => site.type === type)?.url;
+  if (!url) throw new Error(`Site not found: "${type}" of "${title}"`);
+
+  return new URL(url.href.replace(encodeURI("{id}"), id));
+}
diff --git a/src/types/toml.ts b/src/types/feed.ts
similarity index 74%
rename from src/types/toml.ts
rename to src/types/feed.ts
index 881c0f4..d185870 100644
--- a/src/types/toml.ts
+++ b/src/types/feed.ts
@@ -7,6 +7,7 @@ export type List = {
 };
 export type Feed = {
   title: string;
-  text: string;
-  xmlUrl: URL;
+  type?: string;
+  id?: string;
+  xmlUrl?: URL;
 };
diff --git a/src/types/mod.ts b/src/types/mod.ts
index 9de745d..e4ab14f 100644
--- a/src/types/mod.ts
+++ b/src/types/mod.ts
@@ -1,2 +1,3 @@
-export * from "./toml.ts";
 export * from "./opml.ts";
+export * from "./feed.ts";
+export * from "./sites.ts";
diff --git a/src/types/sites.ts b/src/types/sites.ts
new file mode 100644
index 0000000..3b4381b
--- /dev/null
+++ b/src/types/sites.ts
@@ -0,0 +1,4 @@
+export type site = {
+  type: string;
+  url: URL;
+};
diff --git a/test/libs/convert_test.ts b/test/libs/convert_test.ts
index 4540fb2..32a0c0e 100644
--- a/test/libs/convert_test.ts
+++ b/test/libs/convert_test.ts
@@ -1,37 +1,57 @@
 import { assertEquals } from "@std/assert";
-import { convertToOPML, convertToTOML } from "../../src/libs/convert.ts";
+import { convertFromTOML, convertToOPML } from "../../src/libs/convert.ts";
 import type { List, Lists } from "../../src/types/mod.ts";
 
-Deno.test("Parse TOML", () => {
+Deno.test("Parse TOML (RSS)", () => {
+  const toml = `
+[[lists]]
+name = "list name"
+
+[[lists.feeds]]
+title = "feed title"
+xmlUrl = "https://example.com/feed"
+`;
+
   const feeds: Lists = {
-    lists: [
-      {
-        name: "list name",
-        feeds: [
-          {
-            title: "feed title",
-            text: "feed title",
-            xmlUrl: new URL("https://example.com/feed"),
-          },
-        ],
-      },
-    ],
+    lists: [{
+      name: "list name",
+      feeds: [{
+        title: "feed title",
+        xmlUrl: new URL("https://example.com/feed"),
+      }],
+    }],
   };
 
+  assertEquals(convertFromTOML(toml), feeds);
+});
+
+Deno.test("Parse TOML (Site)", () => {
   const toml = `
 [[lists]]
 name = "list name"
 
 [[lists.feeds]]
 title = "feed title"
-text = "feed title"
-xmlUrl = "https://example.com/feed"
+type = "bluesky"
+id = "username"
 `;
 
-  assertEquals(convertToTOML(toml), feeds);
+  const feeds: Lists = {
+    lists: [{
+      name: "list name",
+      feeds: [{
+        title: "feed title",
+        type: "bluesky",
+        id: "username",
+        xmlUrl: new URL("https://bsky.app/profile/username/rss"),
+      }],
+    }],
+  };
+
+  assertEquals(convertFromTOML(toml), feeds);
 });
 
-Deno.test("Convert Lists to OPML", () => {
+Deno.test("Convert Lists to OPML (RSS)", () => {
   const xml = `\
 <?xml version="1.0" encoding="UTF-8"?>
 <opml version="2.0">
@@ -43,14 +63,33 @@ Deno.test("Convert Lists to OPML", () => {
 
   const list: List = {
     name: "list name",
-    feeds: [
-      {
-        title: "feed title",
-        text: "feed title",
-        xmlUrl: new URL("https://example.com/feed"),
-      },
-    ],
+    feeds: [{
+      title: "feed title",
+      xmlUrl: new URL("https://example.com/feed"),
+    }],
+  };
+
+  assertEquals(convertToOPML(list), xml);
+});
+
+Deno.test("Convert Lists to OPML (Site)", () => {
+  const xml = `\
+<?xml version="1.0" encoding="UTF-8"?>
+<opml version="2.0">
+  <body>
+    <outline title="feed title" text="feed title" xmlUrl="https://bsky.app/profile/username/rss" type="rss"/>
+  </body>
+</opml>
+`;
+
+  const list: List = {
+    name: "list name",
+    feeds: [{
+      title: "feed title",
+      type: "bluesky",
+      id: "username",
+    }],
   };
 
-  assertEquals(xml, convertToOPML(list));
+  assertEquals(convertToOPML(list), xml);
 });
diff --git a/test/libs/io_test.ts b/test/libs/io_test.ts
index a0ec944..9f4ba99 100644
--- a/test/libs/io_test.ts
+++ b/test/libs/io_test.ts
@@ -1,7 +1,7 @@
 import { assertEquals, assertIsError } from "@std/assert";
 import { join } from "@std/path";
 import { readTOML, writeXML } from "../../src/libs/io.ts";
-import { convertToOPML, convertToTOML } from "../../src/libs/convert.ts";
+import { convertFromTOML, convertToOPML } from "../../src/libs/convert.ts";
 import type { Lists } from "../../src/types/mod.ts";
 
 Deno.test("Read TOML", async () => {
@@ -18,7 +18,7 @@ xmlUrl = "https://example.com/feed"
   await Deno.writeTextFile(file, toml);
   const lists: Lists = await readTOML(file);
 
-  assertEquals(convertToTOML(toml), lists);
+  assertEquals(convertFromTOML(toml), lists);
 });
 
 Deno.test("Read TOML (File not found)", async () => {
@@ -55,7 +55,6 @@ Deno.test("Write XML", async () => {
         feeds: [
           {
             title: "feed title",
-            text: "feed title",
             xmlUrl: new URL("https://example.com/feed"),
           },
         ],
diff --git a/test/libs/sites_test.ts b/test/libs/sites_test.ts
new file mode 100644
index 0000000..cd2f1a9
--- /dev/null
+++ b/test/libs/sites_test.ts
@@ -0,0 +1,45 @@
+import { assertEquals } from "@std/assert";
+import { transcodeXmlUrl } from "../../src/libs/sites.ts";
+import type { Feed } from "../../src/types/mod.ts";
+
+Deno.test("Get XML URL (Site)", () => {
+  const feed: Feed = {
+    title: "feed title",
+    type: "bluesky",
+    id: "username",
+  };
+  assertEquals(
+    transcodeXmlUrl(feed.title, feed.type, feed.id),
+    new URL("https://bsky.app/profile/username/rss"),
+  );
+});
+
+Deno.test("Get XML URL (type not set)", () => {
+  const feed: Feed = { title: "feed title", id: "username" };
+  try {
+    transcodeXmlUrl(feed.title, undefined, feed.id);
+  } catch (error) {
+    assertEquals(error.message, `Parameter not set: "type" of "${feed.title}"`);
+  }
+});
+
+Deno.test("Get XML URL (id not set)", () => {
+  const feed: Feed = { title: "feed title", type: "bluesky" };
+  try {
+    transcodeXmlUrl(feed.title, feed.type, undefined);
+  } catch (error) {
+    assertEquals(error.message, `Parameter not set: "id" of "${feed.title}"`);
+  }
+});
+
+Deno.test("Get XML URL (Site not found)", () => {
+  const feed: Feed = { title: "feed title", type: "unknown", id: "username" };
+  try {
+    transcodeXmlUrl(feed.title, feed.type, feed.id);
+  } catch (error) {
+    assertEquals(
+      error.message,
+      `Site not found: "${feed.type}" of "${feed.title}"`,
+    );
+  }
+});