diff --git a/CHANGELOG b/CHANGELOG
index f4561be..5b01b20 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,33 @@
+0.1.12
+
+feat: add rank tracker
+
+0.1.11
+
+feat: use s3s' namespace. (see https://github.com/frozenpandaman/s3s/issues/65 for detail)
+refactor: remove `_bid` in exported file
+
+0.1.10
+
+fix: missing draw judgement
+
+0.1.9
+
+update WEB_VIEW_VERSION
+
+0.1.8
+
+feat: add coop export
+
+0.1.7
+
+feat: refetch token when 401 close #5
+feat: add github link to UA
+
+0.1.6
+
+fix: wrong base64 encode/decode. (#4)
+
 0.1.5
 
 fix: rank_up sent on last battle of challenge
diff --git a/README.md b/README.md
index 641a3d3..a59a50e 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,18 @@ Options:
 - If you want to use a different profile, use `-p` to specify the path to the
   profile file.
 
+### Track your rank
+
+- Run
+  `deno run -Ar https://raw.githubusercontent.com/spacemeowx2/s3si.ts/main/initRank.ts`
+  to initialize your rank data. (You can also use `-p` to specify the path to
+  the profile file.)
+
+- Then enter your current rank and rank point. For example: `S+0,300`. And the
+  rank will be saved in the `profile.json`.
+
+- After that, run `s3si.ts`, the rank point will be reported to `stat.ink`.
+
 ### profile.json
 
 ```js
diff --git a/dev_deps.ts b/dev_deps.ts
new file mode 100644
index 0000000..d68d3be
--- /dev/null
+++ b/dev_deps.ts
@@ -0,0 +1 @@
+export { assertEquals } from "https://deno.land/std@0.160.0/testing/asserts.ts";
diff --git a/initRank.ts b/initRank.ts
new file mode 100644
index 0000000..57d13ff
--- /dev/null
+++ b/initRank.ts
@@ -0,0 +1,112 @@
+/**
+ * If rankState in profile.json is not defined, it will be initialized.
+ */
+import { flags } from "./deps.ts";
+import { getBulletToken, getGToken } from "./src/iksm.ts";
+import { checkToken, getBattleDetail, getBattleList } from "./src/splatnet3.ts";
+import { gameId, readline } from "./src/utils.ts";
+import { FileStateBackend } from "./src/state.ts";
+import { BattleListType } from "./src/types.ts";
+import { RANK_PARAMS } from "./src/RankTracker.ts";
+
+const parseArgs = (args: string[]) => {
+  const parsed = flags.parse(args, {
+    string: ["profilePath"],
+    alias: {
+      "help": "h",
+      "profilePath": ["p", "profile-path"],
+    },
+  });
+  return parsed;
+};
+
+const opts = parseArgs(Deno.args);
+if (opts.help) {
+  console.log(
+    `Usage: deno run -A ${Deno.mainModule} [options]
+  
+  Options:
+      --profile-path <path>, -p    Path to config file (default: ./profile.json)
+      --help                       Show this help message and exit`,
+  );
+  Deno.exit(0);
+}
+
+const stateBackend = new FileStateBackend(opts.profilePath ?? "./profile.json");
+let state = await stateBackend.read();
+
+if (state.rankState) {
+  console.log("rankState is already initialized.");
+  Deno.exit(0);
+}
+
+if (!await checkToken(state)) {
+  const sessionToken = state.loginState?.sessionToken;
+
+  if (!sessionToken) {
+    throw new Error("Session token is not set.");
+  }
+
+  const { webServiceToken, userCountry, userLang } = await getGToken({
+    fApi: state.fGen,
+    sessionToken,
+  });
+
+  const bulletToken = await getBulletToken({
+    webServiceToken,
+    userLang,
+    userCountry,
+    appUserAgent: state.appUserAgent,
+  });
+
+  state = {
+    ...state,
+    loginState: {
+      ...state.loginState,
+      gToken: webServiceToken,
+      bulletToken,
+    },
+    userLang: state.userLang ?? userLang,
+    userCountry: state.userCountry ?? userCountry,
+  };
+  await stateBackend.write(state);
+}
+
+const battleList = await getBattleList(state, BattleListType.Bankara);
+if (battleList.length === 0) {
+  console.log("No anarchy battle found. Did you play anarchy?");
+  Deno.exit(0);
+}
+const { vsHistoryDetail: detail } = await getBattleDetail(state, battleList[0]);
+
+console.log(
+  `Your latest anarchy battle is played at ${
+    new Date(detail.playedTime).toLocaleString()
+  }. Please enter your rank after this battle(format: RANK,POINT. S+0,300):`,
+);
+
+while (true) {
+  const userInput = await readline();
+  const [rank, point] = userInput.split(",");
+  const pointNumber = parseInt(point);
+
+  if (!RANK_PARAMS.find((i) => i.rank === rank)) {
+    console.log("Invalid rank. Please enter again:");
+  } else if (isNaN(pointNumber)) {
+    console.log("Invalid point. Please enter again:");
+  } else {
+    state = {
+      ...state,
+      rankState: {
+        gameId: await gameId(detail.id),
+        rank,
+        rankPoint: pointNumber,
+      },
+    };
+
+    break;
+  }
+}
+
+await stateBackend.write(state);
+console.log("rankState is initialized.");
diff --git a/src/GameFetcher.ts b/src/GameFetcher.ts
new file mode 100644
index 0000000..e20ab83
--- /dev/null
+++ b/src/GameFetcher.ts
@@ -0,0 +1,236 @@
+import { Mutex } from "../deps.ts";
+import { RankState, State } from "./state.ts";
+import {
+  getBankaraBattleHistories,
+  getBattleDetail,
+  getCoopDetail,
+  getCoopHistories,
+} from "./splatnet3.ts";
+import {
+  BattleListNode,
+  ChallengeProgress,
+  CoopInfo,
+  CoopListNode,
+  Game,
+  HistoryGroups,
+  VsInfo,
+} from "./types.ts";
+import { Cache, MemoryCache } from "./cache.ts";
+import { gameId } from "./utils.ts";
+import { RankTracker } from "./RankTracker.ts";
+
+/**
+ * Fetch game and cache it. It also fetches bankara match challenge info.
+ */
+export class GameFetcher {
+  state: State;
+  cache: Cache;
+  rankTracker: RankTracker;
+
+  lock: Record<string, Mutex | undefined> = {};
+  bankaraLock = new Mutex();
+  bankaraHistory?: HistoryGroups<BattleListNode>["nodes"];
+  coopLock = new Mutex();
+  coopHistory?: HistoryGroups<CoopListNode>["nodes"];
+
+  constructor(
+    { cache = new MemoryCache(), state }: { state: State; cache?: Cache },
+  ) {
+    this.state = state;
+    this.cache = cache;
+    this.rankTracker = new RankTracker(state.rankState);
+  }
+  private getLock(id: string): Mutex {
+    let cur = this.lock[id];
+
+    if (!cur) {
+      cur = new Mutex();
+      this.lock[id] = cur;
+    }
+
+    return cur;
+  }
+
+  setRankState(state: RankState | undefined) {
+    this.rankTracker.setState(state);
+  }
+
+  async updateRank(): Promise<RankState | undefined> {
+    const finalState = await this.rankTracker.updateState(
+      await this.getBankaraHistory(),
+    );
+    return finalState;
+  }
+
+  getRankStateById(id: string) {
+    return this.rankTracker.getRankStateById(id);
+  }
+
+  getBankaraHistory() {
+    return this.bankaraLock.use(async () => {
+      if (this.bankaraHistory) {
+        return this.bankaraHistory;
+      }
+
+      const { bankaraBattleHistories: { historyGroups } } =
+        await getBankaraBattleHistories(
+          this.state,
+        );
+
+      this.bankaraHistory = historyGroups.nodes;
+
+      return this.bankaraHistory;
+    });
+  }
+  getCoopHistory() {
+    return this.coopLock.use(async () => {
+      if (this.coopHistory) {
+        return this.coopHistory;
+      }
+
+      const { coopResult: { historyGroups } } = await getCoopHistories(
+        this.state,
+      );
+
+      this.coopHistory = historyGroups.nodes;
+
+      return this.coopHistory;
+    });
+  }
+  async getCoopMetaById(id: string): Promise<Omit<CoopInfo, "detail">> {
+    const coopHistory = await this.getCoopHistory();
+    const group = coopHistory.find((i) =>
+      i.historyDetails.nodes.some((i) => i.id === id)
+    );
+
+    if (!group) {
+      return {
+        type: "CoopInfo",
+        listNode: null,
+      };
+    }
+
+    const listNode = group.historyDetails.nodes.find((i) => i.id === id) ??
+      null;
+
+    return {
+      type: "CoopInfo",
+      listNode,
+    };
+  }
+  async getBattleMetaById(id: string): Promise<Omit<VsInfo, "detail">> {
+    const gid = await gameId(id);
+    const bankaraHistory = await this.getBankaraHistory();
+    const gameIdMap = new Map<BattleListNode, string>();
+
+    for (const i of bankaraHistory) {
+      for (const j of i.historyDetails.nodes) {
+        gameIdMap.set(j, await gameId(j.id));
+      }
+    }
+
+    const group = bankaraHistory.find((i) =>
+      i.historyDetails.nodes.some((i) => gameIdMap.get(i) === gid)
+    );
+
+    if (!group) {
+      return {
+        type: "VsInfo",
+        challengeProgress: null,
+        bankaraMatchChallenge: null,
+        listNode: null,
+        rankState: null,
+        rankBeforeState: null,
+      };
+    }
+
+    const { bankaraMatchChallenge } = group;
+    const listNode =
+      group.historyDetails.nodes.find((i) => gameIdMap.get(i) === gid) ??
+        null;
+    const index = group.historyDetails.nodes.indexOf(listNode!);
+
+    let challengeProgress: null | ChallengeProgress = null;
+    if (bankaraMatchChallenge) {
+      const pastBattles = group.historyDetails.nodes.slice(0, index);
+      const { winCount, loseCount } = bankaraMatchChallenge;
+      challengeProgress = {
+        index,
+        winCount: winCount -
+          pastBattles.filter((i) => i.judgement == "WIN").length,
+        loseCount: loseCount -
+          pastBattles.filter((i) =>
+            ["LOSE", "DEEMED_LOSE"].includes(i.judgement)
+          ).length,
+      };
+    }
+
+    const { before, after } = await this.rankTracker.getRankStateById(id) ?? {};
+
+    return {
+      type: "VsInfo",
+      bankaraMatchChallenge,
+      listNode,
+      challengeProgress,
+      rankState: after ?? null,
+      rankBeforeState: before ?? null,
+    };
+  }
+  cacheDetail<T>(
+    id: string,
+    getter: () => Promise<T>,
+  ): Promise<T> {
+    const lock = this.getLock(id);
+
+    return lock.use(async () => {
+      const cached = await this.cache.read<T>(id);
+      if (cached) {
+        return cached;
+      }
+
+      const detail = await getter();
+
+      await this.cache.write(id, detail);
+
+      return detail;
+    });
+  }
+  fetch(type: Game["type"], id: string): Promise<Game> {
+    switch (type) {
+      case "VsInfo":
+        return this.fetchBattle(id);
+      case "CoopInfo":
+        return this.fetchCoop(id);
+      default:
+        throw new Error(`Unknown game type: ${type}`);
+    }
+  }
+  async fetchBattle(id: string): Promise<VsInfo> {
+    const detail = await this.cacheDetail(
+      id,
+      () => getBattleDetail(this.state, id).then((r) => r.vsHistoryDetail),
+    );
+    const metadata = await this.getBattleMetaById(id);
+
+    const game: VsInfo = {
+      ...metadata,
+      detail,
+    };
+
+    return game;
+  }
+  async fetchCoop(id: string): Promise<CoopInfo> {
+    const detail = await this.cacheDetail(
+      id,
+      () => getCoopDetail(this.state, id).then((r) => r.coopHistoryDetail),
+    );
+    const metadata = await this.getCoopMetaById(id);
+
+    const game: CoopInfo = {
+      ...metadata,
+      detail,
+    };
+
+    return game;
+  }
+}
diff --git a/src/RankTracker.test.ts b/src/RankTracker.test.ts
new file mode 100644
index 0000000..36b32e7
--- /dev/null
+++ b/src/RankTracker.test.ts
@@ -0,0 +1,287 @@
+import { RankTracker } from "./RankTracker.ts";
+import { assertEquals } from "../dev_deps.ts";
+import { BattleListNode } from "./types.ts";
+import { base64 } from "../deps.ts";
+import { gameId } from "./utils.ts";
+
+const INIT_STATE = {
+  gameId: await gameId(genId(0)),
+  rank: "B-",
+  rankPoint: 100,
+};
+
+class TestRankTracker extends RankTracker {
+  testGet() {
+    const { state, deltaMap } = this;
+    return {
+      state,
+      deltaMap,
+    };
+  }
+}
+
+function genId(id: number): string {
+  return base64.encode(
+    `VsHistoryDetail-asdf:asdf:20220101T${
+      id.toString().padStart(6, "0")
+    }_------------------------------------`,
+  );
+}
+
+function genOpenWins(
+  { startId, count, udemae }: {
+    startId: number;
+    count: number;
+    udemae: string;
+  },
+) {
+  const result: BattleListNode[] = [];
+  let id = startId;
+
+  for (let i = 0; i < count; i++) {
+    result.push({
+      id: genId(id),
+      udemae,
+      judgement: "WIN",
+      bankaraMatch: {
+        earnedUdemaePoint: 8,
+      },
+    });
+    id += 1;
+  }
+
+  return result;
+}
+
+Deno.test("RankTracker tracks promotion, ignoring INPROGRESS", async () => {
+  const INIT_STATE = {
+    gameId: await gameId(genId(0)),
+    rank: "B+",
+    rankPoint: 850,
+  };
+
+  const tracker = new TestRankTracker(INIT_STATE);
+  assertEquals(tracker.testGet(), {
+    state: INIT_STATE,
+    deltaMap: new Map(),
+  });
+
+  const finalState = await tracker.updateState([{
+    bankaraMatchChallenge: {
+      winCount: 2,
+      loseCount: 0,
+      maxWinCount: 3,
+      maxLoseCount: 3,
+      state: "INPROGRESS",
+      isPromo: true,
+      isUdemaeUp: true,
+      udemaeAfter: "A-",
+      earnedUdemaePoint: null,
+    },
+    historyDetails: {
+      nodes: [{
+        id: await genId(1),
+        udemae: "B+",
+        judgement: "WIN",
+        bankaraMatch: {
+          earnedUdemaePoint: null,
+        },
+      }, {
+        id: await genId(0),
+        udemae: "B+",
+        judgement: "WIN",
+        bankaraMatch: {
+          earnedUdemaePoint: null,
+        },
+      }],
+    },
+  }]);
+
+  assertEquals(finalState, {
+    gameId: await gameId(genId(1)),
+    rank: "B+",
+    rankPoint: 850,
+  });
+});
+
+Deno.test("RankTracker tracks promotion", async () => {
+  const INIT_STATE = {
+    gameId: await gameId(genId(0)),
+    rank: "B+",
+    rankPoint: 850,
+  };
+
+  const tracker = new TestRankTracker(INIT_STATE);
+  assertEquals(tracker.testGet(), {
+    state: INIT_STATE,
+    deltaMap: new Map(),
+  });
+
+  const finalState = await tracker.updateState([{
+    bankaraMatchChallenge: {
+      winCount: 3,
+      loseCount: 0,
+      maxWinCount: 3,
+      maxLoseCount: 3,
+      state: "SUCCEEDED",
+      isPromo: true,
+      isUdemaeUp: true,
+      udemaeAfter: "A-",
+      earnedUdemaePoint: null,
+    },
+    historyDetails: {
+      nodes: [{
+        id: await genId(2),
+        udemae: "B+",
+        judgement: "WIN",
+        bankaraMatch: {
+          earnedUdemaePoint: null,
+        },
+      }, {
+        id: await genId(1),
+        udemae: "B+",
+        judgement: "WIN",
+        bankaraMatch: {
+          earnedUdemaePoint: null,
+        },
+      }, {
+        id: await genId(0),
+        udemae: "B+",
+        judgement: "WIN",
+        bankaraMatch: {
+          earnedUdemaePoint: null,
+        },
+      }],
+    },
+  }]);
+
+  assertEquals(finalState, {
+    gameId: await gameId(genId(2)),
+    rank: "A-",
+    rankPoint: 200,
+  });
+});
+
+Deno.test("RankTracker tracks challenge charge", async () => {
+  const tracker = new TestRankTracker(INIT_STATE);
+  assertEquals(tracker.testGet(), {
+    state: INIT_STATE,
+    deltaMap: new Map(),
+  });
+
+  const finalState = await tracker.updateState([{
+    bankaraMatchChallenge: {
+      winCount: 1,
+      loseCount: 0,
+      maxWinCount: 5,
+      maxLoseCount: 3,
+      isPromo: false,
+      isUdemaeUp: false,
+      udemaeAfter: null,
+      earnedUdemaePoint: null,
+      state: "INPROGRESS",
+    },
+    historyDetails: {
+      nodes: [
+        {
+          id: genId(2),
+          udemae: "B-",
+          judgement: "WIN",
+          bankaraMatch: {
+            earnedUdemaePoint: null,
+          },
+        },
+      ],
+    },
+  }, {
+    bankaraMatchChallenge: null,
+    historyDetails: {
+      nodes: genOpenWins({
+        startId: 0,
+        count: 1,
+        udemae: "B-",
+      }),
+    },
+  }]);
+
+  assertEquals(tracker.testGet().state, INIT_STATE);
+
+  assertEquals(finalState, {
+    gameId: await gameId(genId(2)),
+    rank: "B-",
+    rankPoint: 45,
+  });
+});
+
+Deno.test("RankTracker", async () => {
+  const tracker = new TestRankTracker(INIT_STATE);
+  assertEquals(tracker.testGet(), {
+    state: INIT_STATE,
+    deltaMap: new Map(),
+  });
+
+  const finalState = await tracker.updateState([{
+    bankaraMatchChallenge: null,
+    historyDetails: {
+      nodes: [...genOpenWins({
+        startId: 0,
+        count: 19,
+        udemae: "B-",
+      })].reverse(),
+    },
+  }]);
+
+  assertEquals(tracker.testGet().state, INIT_STATE);
+
+  assertEquals(finalState, {
+    gameId: await gameId(genId(18)),
+    rank: "B-",
+    rankPoint: 244,
+  });
+
+  assertEquals((await tracker.getRankStateById(genId(1)))?.after, {
+    gameId: await gameId(genId(1)),
+    rank: "B-",
+    rankPoint: 108,
+  });
+
+  assertEquals((await tracker.getRankStateById(genId(17)))?.after, {
+    gameId: await gameId(genId(17)),
+    rank: "B-",
+    rankPoint: 236,
+  });
+
+  tracker.setState(finalState);
+
+  assertEquals(tracker.testGet().state, finalState);
+
+  // history goes too far
+  const finalState2 = await tracker.updateState([{
+    bankaraMatchChallenge: null,
+    historyDetails: {
+      nodes: [...genOpenWins({
+        startId: 30,
+        count: 1,
+        udemae: "B-",
+      })].reverse(),
+    },
+  }]);
+  assertEquals(finalState2, undefined);
+
+  await tracker.updateState([{
+    bankaraMatchChallenge: null,
+    historyDetails: {
+      nodes: [...genOpenWins({
+        startId: 0,
+        count: 30,
+        udemae: "B-",
+      })].reverse(),
+    },
+  }]);
+
+  assertEquals((await tracker.getRankStateById(genId(29)))?.after, {
+    gameId: await gameId(genId(29)),
+    rank: "B-",
+    rankPoint: 332,
+  });
+});
diff --git a/src/RankTracker.ts b/src/RankTracker.ts
new file mode 100644
index 0000000..747ffb7
--- /dev/null
+++ b/src/RankTracker.ts
@@ -0,0 +1,269 @@
+import { RankState } from "./state.ts";
+import { BattleListNode, HistoryGroups, RankParam } from "./types.ts";
+import { gameId, parseHistoryDetailId } from "./utils.ts";
+
+const splusParams = () => {
+  const out: RankParam[] = [];
+
+  for (let i = 0; i < 50; i++) {
+    const level = i % 10;
+    const item: RankParam = {
+      rank: `S+${i}`,
+      pointRange: [300 + level * 350, 300 + (level + 1) * 350],
+      charge: 160,
+    };
+    if (level === 9) {
+      item.promotion = true;
+    }
+    out.push(item);
+  }
+
+  out.push({
+    rank: "S+50",
+    pointRange: [0, 9999],
+    charge: 160,
+  });
+
+  return out;
+};
+
+export const RANK_PARAMS: RankParam[] = [{
+  rank: "C-",
+  pointRange: [0, 200],
+  charge: 0,
+}, {
+  rank: "C",
+  pointRange: [200, 400],
+  charge: 20,
+}, {
+  rank: "C+",
+  pointRange: [400, 600],
+  charge: 40,
+  promotion: true,
+}, {
+  rank: "B-",
+  pointRange: [100, 350],
+  charge: 55,
+}, {
+  rank: "B",
+  pointRange: [350, 600],
+  charge: 70,
+}, {
+  rank: "B+",
+  pointRange: [600, 850],
+  charge: 85,
+  promotion: true,
+}, {
+  rank: "A-",
+  pointRange: [200, 500],
+  charge: 100,
+}, {
+  rank: "A",
+  pointRange: [500, 800],
+  charge: 110,
+}, {
+  rank: "A+",
+  pointRange: [800, 1100],
+  charge: 120,
+  promotion: true,
+}, {
+  rank: "S",
+  pointRange: [300, 1000],
+  charge: 150,
+  promotion: true,
+}, ...splusParams()];
+
+type Delta = {
+  beforeGameId: string;
+  gameId: string;
+  rankAfter?: string;
+  rankPoint: number;
+  isPromotion: boolean;
+  isChallengeFirst: boolean;
+};
+
+// TODO: auto rank up using rank params and delta.
+function addRank(state: RankState, delta: Delta): RankState {
+  const { rank, rankPoint } = state;
+  const { gameId, rankAfter, isPromotion, isChallengeFirst } = delta;
+
+  const rankIndex = RANK_PARAMS.findIndex((r) => r.rank === rank);
+
+  if (rankIndex === -1) {
+    throw new Error(`Rank not found: ${rank}`);
+  }
+
+  const rankParam = RANK_PARAMS[rankIndex];
+
+  if (isChallengeFirst) {
+    return {
+      gameId,
+      rank,
+      rankPoint: rankPoint - rankParam.charge,
+    };
+  }
+
+  // S+50 is the highest rank
+  if (rankIndex === RANK_PARAMS.length - 1) {
+    return {
+      gameId,
+      rank,
+      rankPoint: Math.min(rankPoint + delta.rankPoint, rankParam.pointRange[1]),
+    };
+  }
+
+  if (isPromotion) {
+    const nextRankParam = RANK_PARAMS[rankIndex + 1];
+
+    return {
+      gameId,
+      rank: nextRankParam.rank,
+      rankPoint: nextRankParam.pointRange[0],
+    };
+  }
+
+  return {
+    gameId,
+    rank: rankAfter ?? rank,
+    rankPoint: rankPoint + delta.rankPoint,
+  };
+}
+
+const battleTime = (id: string) => {
+  const { timestamp } = parseHistoryDetailId(id);
+
+  const dateStr = timestamp.replace(
+    /(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})/,
+    "$1-$2-$3T$4:$5:$6Z",
+  );
+
+  return new Date(dateStr);
+};
+
+/**
+ * if state is empty, it will not track rank.
+ */
+export class RankTracker {
+  // key: privous game id
+  protected deltaMap: Map<string, Delta> = new Map();
+
+  constructor(protected state: RankState | undefined) {}
+
+  async getRankStateById(
+    id: string,
+  ): Promise<{ before: RankState; after: RankState } | undefined> {
+    if (!this.state) {
+      return;
+    }
+    const gid = await gameId(id);
+
+    let cur = this.state;
+    let before = cur;
+    while (cur.gameId !== gid) {
+      const delta = this.deltaMap.get(cur.gameId);
+      if (!delta) {
+        return;
+      }
+      before = cur;
+      cur = addRank(cur, delta);
+    }
+
+    return {
+      before,
+      after: cur,
+    };
+  }
+
+  setState(state: RankState | undefined) {
+    this.state = state;
+  }
+
+  async updateState(
+    hisotry: HistoryGroups<BattleListNode>["nodes"],
+  ) {
+    if (!this.state) {
+      return;
+    }
+
+    const flatten = await Promise.all(
+      hisotry
+        .flatMap(
+          ({ historyDetails, bankaraMatchChallenge }) => {
+            return historyDetails.nodes.map((j, index) => ({
+              time: battleTime(j.id),
+              gameId: gameId(j.id),
+              bankaraMatchChallenge,
+              index,
+              groupLength: historyDetails.nodes.length,
+              detail: j,
+            }));
+          },
+        )
+        .sort((a, b) => a.time.getTime() - b.time.getTime())
+        .map((i) => i.gameId.then((gameId) => ({ ...i, gameId }))),
+    );
+
+    const index = flatten.findIndex((i) => i.gameId === this.state!.gameId);
+
+    if (index === -1) {
+      return;
+    }
+
+    const unProcessed = flatten.slice(index);
+    const deltaList: Delta[] = [];
+    let beforeGameId = this.state.gameId;
+
+    for (const i of unProcessed.slice(1)) {
+      if (!i.detail.bankaraMatch) {
+        throw new TypeError("bankaraMatch must be defined");
+      }
+
+      let delta: Delta = {
+        beforeGameId,
+        gameId: i.gameId,
+        rankPoint: 0,
+        isPromotion: false,
+        isChallengeFirst: false,
+      };
+      beforeGameId = i.gameId;
+      if (i.bankaraMatchChallenge) {
+        // challenge
+        if (i.index === 0 && i.bankaraMatchChallenge.state !== "INPROGRESS") {
+          // last battle in challenge
+          delta = {
+            ...delta,
+            rankAfter: i.bankaraMatchChallenge.udemaeAfter ?? undefined,
+            rankPoint: i.bankaraMatchChallenge.earnedUdemaePoint ?? 0,
+            isPromotion: i.bankaraMatchChallenge.isPromo ?? false,
+            isChallengeFirst: false,
+          };
+        } else if (i.index === i.groupLength - 1) {
+          // first battle in challenge
+          delta = {
+            ...delta,
+            isChallengeFirst: true,
+          };
+        }
+      } else {
+        // open
+        delta = {
+          ...delta,
+          // TODO: rankAfter should be undefined in open battle
+          rankAfter: i.detail.udemae,
+          rankPoint: i.detail.bankaraMatch?.earnedUdemaePoint ?? 0,
+        };
+      }
+
+      deltaList.push(delta);
+    }
+
+    let curState = this.state;
+
+    for (const delta of deltaList) {
+      this.deltaMap.set(delta.beforeGameId, delta);
+      curState = addRank(curState, delta);
+    }
+
+    return curState;
+  }
+}
diff --git a/src/app.ts b/src/app.ts
index 5bf40c2..e14fdd1 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -1,41 +1,24 @@
 import { getBulletToken, getGToken, loginManually } from "./iksm.ts";
-import { MultiProgressBar, Mutex } from "../deps.ts";
+import { MultiProgressBar } from "../deps.ts";
 import {
   DEFAULT_STATE,
   FileStateBackend,
   State,
   StateBackend,
 } from "./state.ts";
-import {
-  getBankaraBattleHistories,
-  getBattleDetail,
-  getBattleList,
-  getCoopDetail,
-  getCoopHistories,
-  isTokenExpired,
-} from "./splatnet3.ts";
-import {
-  BattleListNode,
-  BattleListType,
-  ChallengeProgress,
-  CoopInfo,
-  CoopListNode,
-  Game,
-  GameExporter,
-  HistoryGroups,
-  VsInfo,
-} from "./types.ts";
-import { Cache, FileCache, MemoryCache } from "./cache.ts";
+import { getBattleList, isTokenExpired } from "./splatnet3.ts";
+import { BattleListType, Game, GameExporter } from "./types.ts";
+import { Cache, FileCache } from "./cache.ts";
 import { StatInkExporter } from "./exporters/stat.ink.ts";
 import { FileExporter } from "./exporters/file.ts";
 import {
   delay,
-  gameId,
   readline,
   RecoverableError,
   retryRecoverableError,
   showError,
 } from "./utils.ts";
+import { GameFetcher } from "./GameFetcher.ts";
 
 export type Opts = {
   profilePath: string;
@@ -54,198 +37,6 @@ export const DEFAULT_OPTS: Opts = {
   monitor: false,
 };
 
-/**
- * Fetch game and cache it.
- */
-class GameFetcher {
-  state: State;
-  cache: Cache;
-  lock: Record<string, Mutex | undefined> = {};
-  bankaraLock = new Mutex();
-  bankaraHistory?: HistoryGroups<BattleListNode>["nodes"];
-  coopLock = new Mutex();
-  coopHistory?: HistoryGroups<CoopListNode>["nodes"];
-
-  constructor(
-    { cache = new MemoryCache(), state }: { state: State; cache?: Cache },
-  ) {
-    this.state = state;
-    this.cache = cache;
-  }
-  private getLock(id: string): Mutex {
-    let cur = this.lock[id];
-
-    if (!cur) {
-      cur = new Mutex();
-      this.lock[id] = cur;
-    }
-
-    return cur;
-  }
-
-  getBankaraHistory() {
-    return this.bankaraLock.use(async () => {
-      if (this.bankaraHistory) {
-        return this.bankaraHistory;
-      }
-
-      const { bankaraBattleHistories: { historyGroups } } =
-        await getBankaraBattleHistories(
-          this.state,
-        );
-
-      this.bankaraHistory = historyGroups.nodes;
-
-      return this.bankaraHistory;
-    });
-  }
-  getCoopHistory() {
-    return this.coopLock.use(async () => {
-      if (this.coopHistory) {
-        return this.coopHistory;
-      }
-
-      const { coopResult: { historyGroups } } = await getCoopHistories(
-        this.state,
-      );
-
-      this.coopHistory = historyGroups.nodes;
-
-      return this.coopHistory;
-    });
-  }
-  async getCoopMetaById(id: string): Promise<Omit<CoopInfo, "detail">> {
-    const coopHistory = await this.getCoopHistory();
-    const group = coopHistory.find((i) =>
-      i.historyDetails.nodes.some((i) => i.id === id)
-    );
-
-    if (!group) {
-      return {
-        type: "CoopInfo",
-        listNode: null,
-      };
-    }
-
-    const listNode = group.historyDetails.nodes.find((i) => i.id === id) ??
-      null;
-
-    return {
-      type: "CoopInfo",
-      listNode,
-    };
-  }
-  async getBattleMetaById(id: string): Promise<Omit<VsInfo, "detail">> {
-    const gid = await gameId(id);
-    const bankaraHistory = await this.getBankaraHistory();
-    const gameIdMap = new Map<BattleListNode, string>();
-
-    for (const i of bankaraHistory) {
-      for (const j of i.historyDetails.nodes) {
-        gameIdMap.set(j, await gameId(j.id));
-      }
-    }
-
-    const group = bankaraHistory.find((i) =>
-      i.historyDetails.nodes.some((i) => gameIdMap.get(i) === gid)
-    );
-
-    if (!group) {
-      return {
-        type: "VsInfo",
-        challengeProgress: null,
-        bankaraMatchChallenge: null,
-        listNode: null,
-      };
-    }
-
-    const { bankaraMatchChallenge } = group;
-    const listNode =
-      group.historyDetails.nodes.find((i) => gameIdMap.get(i) === gid) ??
-        null;
-    const index = group.historyDetails.nodes.indexOf(listNode!);
-
-    let challengeProgress: null | ChallengeProgress = null;
-    if (bankaraMatchChallenge) {
-      const pastBattles = group.historyDetails.nodes.slice(0, index);
-      const { winCount, loseCount } = bankaraMatchChallenge;
-      challengeProgress = {
-        index,
-        winCount: winCount -
-          pastBattles.filter((i) => i.judgement == "WIN").length,
-        loseCount: loseCount -
-          pastBattles.filter((i) =>
-            ["LOSE", "DEEMED_LOSE"].includes(i.judgement)
-          ).length,
-      };
-    }
-
-    return {
-      type: "VsInfo",
-      bankaraMatchChallenge,
-      listNode,
-      challengeProgress,
-    };
-  }
-  cacheDetail<T>(
-    id: string,
-    getter: () => Promise<T>,
-  ): Promise<T> {
-    const lock = this.getLock(id);
-
-    return lock.use(async () => {
-      const cached = await this.cache.read<T>(id);
-      if (cached) {
-        return cached;
-      }
-
-      const detail = await getter();
-
-      await this.cache.write(id, detail);
-
-      return detail;
-    });
-  }
-  fetch(type: Game["type"], id: string): Promise<Game> {
-    switch (type) {
-      case "VsInfo":
-        return this.fetchBattle(id);
-      case "CoopInfo":
-        return this.fetchCoop(id);
-      default:
-        throw new Error(`Unknown game type: ${type}`);
-    }
-  }
-  async fetchBattle(id: string): Promise<VsInfo> {
-    const detail = await this.cacheDetail(
-      id,
-      () => getBattleDetail(this.state, id).then((r) => r.vsHistoryDetail),
-    );
-    const metadata = await this.getBattleMetaById(id);
-
-    const game: VsInfo = {
-      ...metadata,
-      detail,
-    };
-
-    return game;
-  }
-  async fetchCoop(id: string): Promise<CoopInfo> {
-    const detail = await this.cacheDetail(
-      id,
-      () => getCoopDetail(this.state, id).then((r) => r.coopHistoryDetail),
-    );
-    const metadata = await this.getCoopMetaById(id);
-
-    const game: CoopInfo = {
-      ...metadata,
-      detail,
-    };
-
-    return game;
-  }
-}
-
 type Progress = {
   currentUrl?: string;
   current: number;
@@ -378,6 +169,8 @@ export class App {
         state: this.state,
       });
 
+      const finalRankState = await fetcher.updateRank();
+
       await Promise.all(
         exporters.map((e) =>
           showError(
@@ -398,6 +191,13 @@ export class App {
         ),
       );
 
+      // save rankState only if all exporters succeeded
+      fetcher.setRankState(finalRankState);
+      await this.writeState({
+        ...this.state,
+        rankState: finalRankState,
+      });
+
       endBar();
     }
 
diff --git a/src/exporters/stat.ink.ts b/src/exporters/stat.ink.ts
index 69e7509..d0d17b5 100644
--- a/src/exporters/stat.ink.ts
+++ b/src/exporters/stat.ink.ts
@@ -173,8 +173,14 @@ export class StatInkExporter implements GameExporter {
     return result;
   }
   async mapBattle(
-    { challengeProgress, bankaraMatchChallenge, listNode, detail: vsDetail }:
-      VsInfo,
+    {
+      challengeProgress,
+      bankaraMatchChallenge,
+      listNode,
+      detail: vsDetail,
+      rankBeforeState,
+      rankState,
+    }: VsInfo,
   ): Promise<StatInkPostBody> {
     const {
       knockout,
@@ -276,6 +282,19 @@ export class StatInkExporter implements GameExporter {
       result.challenge_lose = challengeProgress.loseCount;
     }
 
+    if (rankBeforeState) {
+      result.rank_before_exp = rankBeforeState.rankPoint;
+    }
+
+    if (rankState) {
+      result.rank_after_exp = rankState.rankPoint;
+      if (!result.rank_after) {
+        [result.rank_after, result.rank_after_s_plus] = parseUdemae(
+          rankState.rank,
+        );
+      }
+    }
+
     return result;
   }
 }
diff --git a/src/state.ts b/src/state.ts
index fd611de..332f023 100644
--- a/src/state.ts
+++ b/src/state.ts
@@ -3,6 +3,15 @@ export type LoginState = {
   gToken?: string;
   bulletToken?: string;
 };
+export type RankState = {
+  // generated by gameId(battle.id)
+  // TODO: If the gameId does not exist, the tracker will assume that the user has
+  // not played a bankara match. And it will start tracking from the first match
+  gameId: string;
+  // C-, B, A+, S, S+0, S+12
+  rank: string;
+  rankPoint: number;
+};
 export type State = {
   loginState?: LoginState;
   fGen: string;
@@ -10,6 +19,8 @@ export type State = {
   userLang?: string;
   userCountry?: string;
 
+  rankState?: RankState;
+
   cacheDir: string;
 
   // Exporter config
diff --git a/src/types.ts b/src/types.ts
index 3cfe87b..236cddf 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,3 +1,5 @@
+import { RankState } from "./state.ts";
+
 export enum Queries {
   HomeQuery = "dba47124d5ec3090c97ba17db5d2f4b3",
   LatestBattleHistoriesQuery = "7d8b560e31617e981cf7c8aa1ca13a00",
@@ -43,6 +45,9 @@ export type BattleListNode = {
   id: string;
   udemae: string;
   judgement: "LOSE" | "WIN" | "DEEMED_LOSE" | "EXEMPTED_LOSE" | "DRAW";
+  bankaraMatch: null | {
+    earnedUdemaePoint: null | number;
+  };
 };
 export type CoopListNode = {
   id: string;
@@ -103,6 +108,8 @@ export type VsInfo = {
   listNode: null | BattleListNode;
   bankaraMatchChallenge: null | BankaraMatchChallenge;
   challengeProgress: null | ChallengeProgress;
+  rankState: null | RankState;
+  rankBeforeState: null | RankState;
   detail: VsHistoryDetail;
 };
 // Salmon run
@@ -164,6 +171,12 @@ export type GameExporter<
   exportGame: (game: T) => Promise<{ url?: string }>;
 };
 
+export type BankaraBattleHistories = {
+  bankaraBattleHistories: {
+    historyGroups: HistoryGroups<BattleListNode>;
+  };
+};
+
 export type RespMap = {
   [Queries.HomeQuery]: {
     currentPlayer: {
@@ -193,11 +206,7 @@ export type RespMap = {
       historyGroups: HistoryGroups<BattleListNode>;
     };
   };
-  [Queries.BankaraBattleHistoriesQuery]: {
-    bankaraBattleHistories: {
-      historyGroups: HistoryGroups<BattleListNode>;
-    };
-  };
+  [Queries.BankaraBattleHistoriesQuery]: BankaraBattleHistories;
   [Queries.PrivateBattleHistoriesQuery]: {
     privateBattleHistories: {
       historyGroups: HistoryGroups<BattleListNode>;
@@ -330,3 +339,10 @@ export type StatInkPostResponse = {
   id: string;
   url: string;
 };
+
+export type RankParam = {
+  rank: string;
+  pointRange: [number, number];
+  charge: number;
+  promotion?: boolean;
+};
diff --git a/src/utils.ts b/src/utils.ts
index cb4bf72..de5619d 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -19,9 +19,11 @@ export function urlBase64Decode(data: string) {
   );
 }
 
-export async function readline() {
+export async function readline(
+  { skipEmpty = true }: { skipEmpty?: boolean } = {},
+) {
   for await (const line of stdinLines) {
-    if (line !== "") {
+    if (!skipEmpty || line !== "") {
       return line;
     }
   }