diff --git a/README.md b/README.md
index 1036589..a21fa17 100644
--- a/README.md
+++ b/README.md
@@ -79,6 +79,13 @@ yarn run start
 # You can change the host of CodeChain and DB host on the config/dev.json
 ```
 
+### Check CCCChanges
+
+If you run the Indexer with the environment `ENABLE_CCC_CHANGES_CHECK` variable,
+the Indexer checks to see if CCCChanges is well calculated.
+If you want to receive an email when an error is found, please set the `SENDGRID_API_KEY` and `SENDGRID_TO` variables.
+If you want to receive a slack notification, please set the `SLACK_WEBHOOK` variable.
+
 ## Run (for production)
 
 ```
diff --git a/package.json b/package.json
index e69c5a4..141b0f6 100644
--- a/package.json
+++ b/package.json
@@ -10,6 +10,8 @@
     "yarn": "^1.10.0"
   },
   "dependencies": {
+    "@sendgrid/mail": "^6.4.0",
+    "@slack/client": "^5.0.1",
     "async-lock": "^1.1.4",
     "bignumber.js": "^7.2.1",
     "buffer": "^5.2.1",
diff --git a/src/checker/email.ts b/src/checker/email.ts
new file mode 100644
index 0000000..4c46b63
--- /dev/null
+++ b/src/checker/email.ts
@@ -0,0 +1,99 @@
+import * as sendgrid from "@sendgrid/mail";
+
+export interface Email {
+    sendError(msg: string): void;
+    sendWarning(text: string): void;
+    sendInfo(title: string, msg: string): void;
+}
+
+class NullEmail implements Email {
+    public sendError(_: string): void {
+        // empty
+    }
+    public sendWarning(_: string): void {
+        // empty
+    }
+    public sendInfo(_: string, __: string): void {
+        // empty
+    }
+}
+
+const from = "no-reply+indexer-CCCChanges-checker@devop.codechain.io";
+
+function createTitle(params: {
+    title: string;
+    tag: string;
+    level: string;
+}): string {
+    const { title, tag, level } = params;
+    return `[${level}]${tag} ${title}`;
+}
+
+// tslint:disable-next-line:max-classes-per-file
+class Sendgrid implements Email {
+    private readonly tag: string;
+    private readonly to: string;
+
+    public constructor(params: {
+        tag: string;
+        sendgridApiKey: string;
+        to: string;
+    }) {
+        const { tag, sendgridApiKey, to } = params;
+        this.tag = tag;
+        sendgrid.setApiKey(sendgridApiKey);
+        this.to = to;
+    }
+
+    public sendError(text: string): void {
+        const subject = createTitle({
+            tag: this.tag,
+            title: "has a problem.",
+            level: "error"
+        });
+        this.send(subject, text);
+    }
+
+    public sendWarning(text: string): void {
+        const subject = createTitle({
+            tag: this.tag,
+            title: "finds a problem.",
+            level: "warn"
+        });
+        this.send(subject, text);
+    }
+
+    public sendInfo(title: string, text: string): void {
+        const subject = createTitle({ tag: this.tag, title, level: "info" });
+        this.send(subject, text);
+    }
+
+    private send(subject: string, value: string): void {
+        sendgrid
+            .send({
+                subject,
+                from,
+                to: this.to,
+                content: [{ type: "text/html", value }]
+            })
+            .catch(console.error);
+    }
+}
+
+export function createEmail(params: {
+    tag: string;
+    to?: string;
+    sendgridApiKey?: string;
+}): Email {
+    const { tag, to, sendgridApiKey } = params;
+    if (sendgridApiKey != null) {
+        if (to == null) {
+            throw Error("The email destination is not set");
+        }
+        console.log("Sendgrid key is set");
+        return new Sendgrid({ tag, sendgridApiKey, to });
+    } else {
+        console.log("Donot use sendgrid");
+        return new NullEmail();
+    }
+}
diff --git a/src/checker/index.ts b/src/checker/index.ts
new file mode 100644
index 0000000..35bd418
--- /dev/null
+++ b/src/checker/index.ts
@@ -0,0 +1,184 @@
+import { SDK } from "codechain-sdk";
+import { IndexerConfig } from "../config";
+import * as BlockModel from "../models/logic/block";
+import * as CCCChangeModel from "../models/logic/cccChange";
+import { createEmail, Email } from "./email";
+import { createSlack, Slack } from "./slack";
+
+export async function run(sdk: SDK, options: IndexerConfig) {
+    console.log("Start to check CCCChanges");
+    const prevBlockInstance = await BlockModel.getLatestBlock();
+    let lastCheckedBlockNumber: number | "NotExist";
+
+    const email = createEmail({
+        tag: `[${options.codechain.networkId}][indexer-cccchanges-checker]`,
+        sendgridApiKey: process.env.SENDGRID_API_KEY,
+        to: process.env.SENDGRID_TO
+    });
+
+    const slack = createSlack(
+        `[${options.codechain.networkId}][indexer-cccchanges-checker]`,
+        process.env.SLACK_WEBHOOK
+    );
+
+    if (prevBlockInstance) {
+        lastCheckedBlockNumber = prevBlockInstance.get({ plain: true }).number;
+    } else {
+        lastCheckedBlockNumber = "NotExist";
+    }
+    for (;;) {
+        await new Promise(resolve => setTimeout(resolve, 5 * 1000));
+        if (lastCheckedBlockNumber === "NotExist") {
+            const blockInstance = await BlockModel.getByNumber(0);
+            if (blockInstance === null) {
+                continue;
+            } else {
+                lastCheckedBlockNumber = -1;
+                continue;
+            }
+        }
+
+        const latestBlock = (await BlockModel.getLatestBlock())!;
+        const latestBlockNumber: number = latestBlock.get("number");
+
+        const checkFrom = lastCheckedBlockNumber + 1;
+        const checkTo = latestBlockNumber - 1;
+        if (checkTo > checkFrom) {
+            await checkBlocks(checkFrom, checkTo, sdk, email, slack);
+            lastCheckedBlockNumber = checkTo;
+        } else {
+            continue;
+        }
+    }
+}
+
+async function checkBlocks(
+    fromBlockNumber: number,
+    toBlockNumber: number,
+    sdk: SDK,
+    email: Email,
+    slack: Slack
+) {
+    if (fromBlockNumber >= toBlockNumber) {
+        throw new Error(
+            `Invalid fromBlockNumber(${fromBlockNumber}) and toBlockNumber(${toBlockNumber})`
+        );
+    }
+
+    let beforeBlockNumber = fromBlockNumber;
+    let afterBlockNumber = fromBlockNumber + 1;
+
+    for (;;) {
+        const cccChanges = (await CCCChangeModel.getByBlockNumber(
+            afterBlockNumber
+        )).map(instance => instance.get({ plain: true }));
+
+        const balanceChangeMap: Map<string, number> = new Map();
+        cccChanges.forEach(cccChange => {
+            /// Total CCC does not exceed Number.MAX_SAFE_INTEGER;
+            const change = parseInt(cccChange.change, 10);
+            const address = cccChange.address;
+
+            if (balanceChangeMap.has(cccChange.address)) {
+                balanceChangeMap.set(
+                    address,
+                    balanceChangeMap.get(address)! + change
+                );
+            } else {
+                balanceChangeMap.set(address, change);
+            }
+        });
+
+        const promises = Array.from(balanceChangeMap).map(
+            async ([address, change]) => {
+                const beforeBalanceUInt = await sdk.rpc.chain.getBalance(
+                    address,
+                    beforeBlockNumber
+                );
+                const afterBalanceUInt = await sdk.rpc.chain.getBalance(
+                    address,
+                    afterBlockNumber
+                );
+
+                const beforeBalance = parseInt(
+                    beforeBalanceUInt.toString(10),
+                    10
+                );
+                const afterBalance = parseInt(
+                    afterBalanceUInt.toString(10),
+                    10
+                );
+                const expected = afterBalance - beforeBalance;
+                const actual = change;
+
+                if (actual !== expected) {
+                    sendAlarm({
+                        address,
+                        beforeBlockNumber,
+                        afterBlockNumber,
+                        beforeBalance,
+                        afterBalance,
+                        actual,
+                        expected,
+                        email,
+                        slack
+                    });
+                }
+            }
+        );
+
+        await Promise.all(promises);
+        if (afterBlockNumber === toBlockNumber) {
+            return;
+        }
+        beforeBlockNumber += 1;
+        afterBlockNumber += 1;
+    }
+}
+
+function sendAlarm({
+    address,
+    beforeBlockNumber,
+    afterBlockNumber,
+    actual,
+    expected,
+    beforeBalance,
+    afterBalance,
+    email,
+    slack
+}: {
+    address: string;
+    beforeBlockNumber: number;
+    afterBlockNumber: number;
+    actual: number;
+    expected: number;
+    beforeBalance: number;
+    afterBalance: number;
+    email: Email;
+    slack: Slack;
+}) {
+    /// TODO Send an email.
+    const firstLine = "Mismatch found";
+    console.group(firstLine);
+
+    const lines = [
+        `Address: ${address}`,
+        `Balance at ${beforeBlockNumber}: ${beforeBalance}`,
+        `Balance at ${afterBlockNumber}: ${afterBalance}`,
+        `Actual CCCChanges: ${actual}`,
+        `Exepcted CCCChanges: ${expected}`
+    ];
+    lines.forEach(line => {
+        console.error(line);
+    });
+    console.groupEnd();
+
+    email.sendError(`
+    <p>${firstLine}</p>
+    <ul>
+    ${lines.map(line => `<li>${line}</li>`).join("\n")}
+    </ul>
+    `);
+
+    slack.sendError([firstLine, ...lines].join("\n"));
+}
diff --git a/src/checker/slack.ts b/src/checker/slack.ts
new file mode 100644
index 0000000..4e5543e
--- /dev/null
+++ b/src/checker/slack.ts
@@ -0,0 +1,85 @@
+import { IncomingWebhook, MessageAttachment } from "@slack/client";
+import * as _ from "lodash";
+
+export interface Slack {
+    sendError(msg: string): void;
+    sendWarning(text: string): void;
+    sendInfo(title: string, text: string): void;
+}
+
+class NullSlack implements Slack {
+    public sendError(__: string) {
+        // empty
+    }
+    public sendWarning(__: string) {
+        // empty
+    }
+    public sendInfo(__: string, ___: string) {
+        // empty
+    }
+}
+
+// tslint:disable-next-line:max-classes-per-file
+class SlackWebhook implements Slack {
+    private readonly tag: string;
+    private readonly webhook: IncomingWebhook;
+    private unsentAttachments: MessageAttachment[] = [];
+
+    public constructor(tag: string, slackWebhookUrl: string) {
+        this.tag = tag;
+        this.webhook = new IncomingWebhook(slackWebhookUrl, {});
+    }
+
+    public sendError(text: string) {
+        const title = `[error]${this.tag} has a problem`;
+        this.unsentAttachments.push({ title, text, color: "danger" });
+        this.send();
+    }
+
+    public sendWarning(text: string) {
+        console.log(`Warning: ${text}`);
+        this.unsentAttachments.push({
+            title: `[warn]${this.tag} finds a problem`,
+            text,
+            color: "warning"
+        });
+        this.send();
+    }
+
+    public sendInfo(title: string, text: string) {
+        console.log(`Info: ${text}`);
+        this.unsentAttachments.push({
+            title: `[info]${this.tag} ${title}`,
+            text,
+            color: "good"
+        });
+        this.send();
+    }
+
+    private send() {
+        this.webhook
+            .send({
+                attachments: this.unsentAttachments
+            })
+            .catch((err: Error) => {
+                if (err) {
+                    console.error("IncomingWebhook failed!", err);
+                    return;
+                }
+            });
+        this.unsentAttachments = [];
+    }
+}
+
+export function createSlack(
+    tag: string,
+    slackWebhookUrl: string | undefined
+): Slack {
+    if (slackWebhookUrl) {
+        console.log("Slack connected");
+        return new SlackWebhook(tag, slackWebhookUrl);
+    } else {
+        console.log("Slack not connected");
+        return new NullSlack();
+    }
+}
diff --git a/src/index.ts b/src/index.ts
index 64a42a8..176575f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,4 +1,5 @@
 import * as http from "http";
+import { run as runChecker } from "./checker";
 import { IndexerConfig } from "./config";
 import { IndexerContext } from "./context";
 import log from "./log";
@@ -38,6 +39,10 @@ async function runServer() {
         );
     });
     context.worker.run();
+
+    if (process.env.ENABLE_CCC_CHANGES_CHECK) {
+        runChecker(context.sdk, context.options).catch(console.error);
+    }
 }
 
 runServer();
diff --git a/src/models/logic/block.ts b/src/models/logic/block.ts
index ba58e4a..b2f10ef 100644
--- a/src/models/logic/block.ts
+++ b/src/models/logic/block.ts
@@ -327,6 +327,13 @@ async function parseSigners({
         [parentBlockNumber]
     );
 
+    // PoW or Solo consensus
+    if (validatorAddresses === null) {
+        return {
+            missedSigners: []
+        };
+    }
+
     const missedValidatorIndices: number[] = unsetBitIndices(
         precommitBitset,
         validatorAddresses.length
diff --git a/src/models/logic/cccChange.ts b/src/models/logic/cccChange.ts
index 38590ec..ab0f4cd 100644
--- a/src/models/logic/cccChange.ts
+++ b/src/models/logic/cccChange.ts
@@ -245,3 +245,25 @@ export async function getCountByAddress(
         throw Exception.DBError();
     }
 }
+
+export async function getByBlockNumber(
+    blockNumber: number
+): Promise<CCCChangeInstance[]> {
+    try {
+        return await models.CCCChange.findAll({
+            attributes: [
+                "address",
+                "change",
+                "blockNumber",
+                "reason",
+                "transactionHash"
+            ],
+            where: {
+                blockNumber
+            }
+        });
+    } catch (err) {
+        console.error(err);
+        throw Exception.DBError();
+    }
+}
diff --git a/yarn.lock b/yarn.lock
index 0f7f9f8..f9ab330 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2,6 +2,31 @@
 # yarn lockfile v1
 
 
+"@sendgrid/client@^6.4.0":
+  version "6.4.0"
+  resolved "https://registry.yarnpkg.com/@sendgrid/client/-/client-6.4.0.tgz#d58df30adea5d7d09e747e2b61f9f859deeda798"
+  integrity sha512-GcO+hKXMQiwN0xMGfPITArlj4Nab1vZsrsRLmsJlcXGZV1V1zQC6XuAWJv6MGDd0hr/jKaXmCJ1XMYkxIRQHFw==
+  dependencies:
+    "@sendgrid/helpers" "^6.4.0"
+    "@types/request" "^2.0.3"
+    request "^2.88.0"
+
+"@sendgrid/helpers@^6.4.0":
+  version "6.4.0"
+  resolved "https://registry.yarnpkg.com/@sendgrid/helpers/-/helpers-6.4.0.tgz#f9001cbe2f34e2c264d30fcf71aa5b9c3cde49aa"
+  integrity sha512-1dDDXauArHyxwTKFFfWvQpsijmwalyLgwoQJ3FRCssFq1RfqYDgFhRg0Xs3v/IXS2jkKWePSWiPORSR4Sysdpw==
+  dependencies:
+    chalk "^2.0.1"
+    deepmerge "^2.1.1"
+
+"@sendgrid/mail@^6.4.0":
+  version "6.4.0"
+  resolved "https://registry.yarnpkg.com/@sendgrid/mail/-/mail-6.4.0.tgz#21d022f7fae57dcdc5910eeca5ed318df21e5f51"
+  integrity sha512-pVzbqbxhZ4FUN6iSIksRLtyXRPurrcee1i0noPDStDCLlHVwUR+TofeeKIFWGpIvbbk5UR6S6iV/U5ie8Kdblw==
+  dependencies:
+    "@sendgrid/client" "^6.4.0"
+    "@sendgrid/helpers" "^6.4.0"
+
 "@sinonjs/commons@^1", "@sinonjs/commons@^1.0.2", "@sinonjs/commons@^1.3.1":
   version "1.3.1"
   resolved "https://registry.yarnpkg.com/@sinonjs/commons/-/commons-1.3.1.tgz#ba4ae5fa908f7d8b96b0ec8df0665aca2d8695a4"
@@ -31,6 +56,72 @@
   resolved "https://registry.yarnpkg.com/@sinonjs/text-encoding/-/text-encoding-0.7.1.tgz#8da5c6530915653f3a1f38fd5f101d8c3f8079c5"
   integrity sha512-+iTbntw2IZPb/anVDbypzfQa+ay64MW0Zo8aJ8gZPWMMK6/OubMVb6lUPMagqjOPnmtauXnFCACVl3O7ogjeqQ==
 
+"@slack/client@^5.0.1":
+  version "5.0.1"
+  resolved "https://registry.yarnpkg.com/@slack/client/-/client-5.0.1.tgz#57a5d4d977e3763f44a4dca321a7dbb73c6473af"
+  integrity sha512-rU3x3pVhKq+9gt2sDdQI6toYc9BmLCDU9UYpnGhlHWV+ebHXepftMLOuZqjt2inK9XLzz5XqJYKdsyfbCuwiJA==
+  dependencies:
+    "@slack/logger" "^1.0.0"
+    "@slack/rtm-api" "^5.0.1"
+    "@slack/types" "^1.0.0"
+    "@slack/web-api" "^5.0.1"
+    "@slack/webhook" "^5.0.0"
+
+"@slack/logger@^1.0.0":
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/@slack/logger/-/logger-1.0.0.tgz#e529974c7111f8a62d794a79cd807eee1628088b"
+  integrity sha512-QDYhQR/58xKfB5iquvQwfpxPsmKPP/5SuDp8hRhZeUluCHsP1qBCOc3sW2Xb3cydxK0PAEnkLbBJf/ezsGwtlA==
+  dependencies:
+    "@types/node" ">=8.9.0"
+
+"@slack/rtm-api@^5.0.1":
+  version "5.0.1"
+  resolved "https://registry.yarnpkg.com/@slack/rtm-api/-/rtm-api-5.0.1.tgz#7663f418336c86c9f081890f0d3b4ce8f521d2a3"
+  integrity sha512-M8qcWssFg9SmNUSkxDE230ahl+toRJKRG76PluGL6EqlPcbLqzJYpwPBTPLq6WADYo6yNd6WGGQ4Qtzw/b7rvw==
+  dependencies:
+    "@slack/logger" "^1.0.0"
+    "@slack/web-api" "^5.0.1"
+    "@types/node" ">=8.9.0"
+    "@types/p-queue" "^2.3.2"
+    "@types/ws" "^5.1.1"
+    eventemitter3 "^3.1.0"
+    finity "^0.5.4"
+    p-cancelable "^1.1.0"
+    p-queue "^2.4.2"
+    ws "^5.2.0"
+
+"@slack/types@^1.0.0":
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/@slack/types/-/types-1.0.0.tgz#1dc7a63b293c4911e474197585c3feda012df17a"
+  integrity sha512-IktC4uD/CHfLQcSitKSmjmRu4a6+Nf/KzfS6dTgUlDzENhh26l8aESKAuIpvYD5VOOE6NxDDIAdPJOXBvUGxlg==
+
+"@slack/web-api@^5.0.1":
+  version "5.0.1"
+  resolved "https://registry.yarnpkg.com/@slack/web-api/-/web-api-5.0.1.tgz#f46ecd2dd8b8104144082c079a4f53ec7737f327"
+  integrity sha512-L2Nc8P+NjXH1yqnsNhqxsrbpW3Qv+//9X5PQqcM3bctDmvmwTuhuM1X208RVD2avhnC89aghY5PssyaayWj5sA==
+  dependencies:
+    "@slack/logger" "^1.0.0"
+    "@slack/types" "^1.0.0"
+    "@types/form-data" "^2.2.1"
+    "@types/is-stream" "^1.1.0"
+    "@types/node" ">=8.9.0"
+    "@types/p-queue" "^2.3.2"
+    axios "^0.18.0"
+    eventemitter3 "^3.1.0"
+    form-data "^2.3.3"
+    is-stream "^1.1.0"
+    p-queue "^2.4.2"
+    p-retry "^4.0.0"
+
+"@slack/webhook@^5.0.0":
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/@slack/webhook/-/webhook-5.0.0.tgz#0044a3940afc16cbc607c71acdffddb9e9d4f161"
+  integrity sha512-cDj3kz3x9z9271xPNzlwb90DpKTYybG2OWPJHigJL8FegR80rzQyD0v4bGuStGGkHbAYDKE2BMpJambR55hnSg==
+  dependencies:
+    "@slack/types" "^1.0.0"
+    "@types/node" ">=8.9.0"
+    axios "^0.18.0"
+
 "@types/async-lock@^1.1.1":
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/@types/async-lock/-/async-lock-1.1.1.tgz#81f218213bebcc5f740efe9648272c774a2e4b4b"
@@ -99,6 +190,11 @@
   dependencies:
     "@types/node" "*"
 
+"@types/events@*":
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/@types/events/-/events-3.0.0.tgz#2862f3f58a9a7f7c3e78d79f130dd4d71c25c2a7"
+  integrity sha512-EaObqwIvayI5a8dCzhFrjKzVwKLxjoG9T6Ppd5CEo07LRKfQ8Yokw54r5+Wq7FaBQ+yXRvQAYPrHwya1/UFt9g==
+
 "@types/express-serve-static-core@*":
   version "4.16.1"
   resolved "https://registry.yarnpkg.com/@types/express-serve-static-core/-/express-serve-static-core-4.16.1.tgz#35df7b302299a4ab138a643617bd44078e74d44e"
@@ -116,7 +212,7 @@
     "@types/express-serve-static-core" "*"
     "@types/serve-static" "*"
 
-"@types/form-data@*":
+"@types/form-data@*", "@types/form-data@^2.2.1":
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/@types/form-data/-/form-data-2.2.1.tgz#ee2b3b8eaa11c0938289953606b745b738c54b1e"
   integrity sha512-JAMFhOaHIciYVh8fb5/83nmuO/AHwmto+Hq7a9y8FzLDcC1KCU344XDOMEmahnrTFlHjgh4L0WJFczNIX2GxnQ==
@@ -135,6 +231,13 @@
   dependencies:
     http-status-codes "*"
 
+"@types/is-stream@^1.1.0":
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/@types/is-stream/-/is-stream-1.1.0.tgz#b84d7bb207a210f2af9bed431dc0fbe9c4143be1"
+  integrity sha512-jkZatu4QVbR60mpIzjINmtS1ZF4a/FqdTUTBeQDVOQ2PYyidtwFKr0B5G6ERukKwliq+7mIXvxyppwzG5EgRYg==
+  dependencies:
+    "@types/node" "*"
+
 "@types/joi@^14.3.2":
   version "14.3.2"
   resolved "https://registry.yarnpkg.com/@types/joi/-/joi-14.3.2.tgz#eff771f0b19698b8e6e7c6fe6b625e07e2618fe9"
@@ -167,11 +270,21 @@
   resolved "https://registry.yarnpkg.com/@types/node/-/node-11.9.5.tgz#011eece9d3f839a806b63973e228f85967b79ed3"
   integrity sha512-vVjM0SVzgaOUpflq4GYBvCpozes8OgIIS5gVXVka+OfK3hvnkC1i93U8WiY2OtNE4XUWyyy/86Kf6e0IHTQw1Q==
 
+"@types/node@>=8.9.0":
+  version "12.6.1"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-12.6.1.tgz#d5544f6de0aae03eefbb63d5120f6c8be0691946"
+  integrity sha512-rp7La3m845mSESCgsJePNL/JQyhkOJA6G4vcwvVgkDAwHhGdq5GCumxmPjEk1MZf+8p5ZQAUE7tqgQRQTXN7uQ==
+
 "@types/node@^10.11.7", "@types/node@^10.3.5":
   version "10.12.27"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-10.12.27.tgz#eb3843f15d0ba0986cc7e4d734d2ee8b50709ef8"
   integrity sha512-e9wgeY6gaY21on3ve0xAjgBVjGDWq/xUteK0ujsE53bUoxycMkqfnkUgMt6ffZtykZ5X12Mg3T7Pw4TRCObDKg==
 
+"@types/p-queue@^2.3.2":
+  version "2.3.2"
+  resolved "https://registry.yarnpkg.com/@types/p-queue/-/p-queue-2.3.2.tgz#16bc5fece69ef85efaf2bce8b13f3ebe39c5a1c8"
+  integrity sha512-eKAv5Ql6k78dh3ULCsSBxX6bFNuGjTmof5Q/T6PiECDq0Yf8IIn46jCyp3RJvCi8owaEmm3DZH1PEImjBMd/vQ==
+
 "@types/pg-types@*":
   version "1.11.4"
   resolved "https://registry.yarnpkg.com/@types/pg-types/-/pg-types-1.11.4.tgz#8d7c59fb509ce3dca3f8bae589252051c639a9a8"
@@ -192,7 +305,7 @@
   resolved "https://registry.yarnpkg.com/@types/range-parser/-/range-parser-1.2.3.tgz#7ee330ba7caafb98090bece86a5ee44115904c2c"
   integrity sha512-ewFXqrQHlFsgc09MK5jP5iR7vumV/BYayNC6PgJO2LPe8vrnNFyjQjSppfEngITi0qvfKtzFvgKymGheFM9UOA==
 
-"@types/request@^2.48.1":
+"@types/request@^2.0.3", "@types/request@^2.48.1":
   version "2.48.1"
   resolved "https://registry.yarnpkg.com/@types/request/-/request-2.48.1.tgz#e402d691aa6670fbbff1957b15f1270230ab42fa"
   integrity sha512-ZgEZ1TiD+KGA9LiAAPPJL68Id2UWfeSO62ijSXZjFJArVV+2pKcsVHmrcu+1oiE3q6eDGiFiSolRc4JHoerBBg==
@@ -202,6 +315,11 @@
     "@types/node" "*"
     "@types/tough-cookie" "*"
 
+"@types/retry@^0.12.0":
+  version "0.12.0"
+  resolved "https://registry.yarnpkg.com/@types/retry/-/retry-0.12.0.tgz#2b35eccfcee7d38cd72ad99232fbd58bffb3c84d"
+  integrity sha512-wWKOClTTiizcZhXnPY4wikVAwmdYHp8q6DmC+EJUzAMsycb7HB32Kh9RN4+0gExjmPmZSAQjgURXIGATPegAvA==
+
 "@types/semver@^5.5.0":
   version "5.5.0"
   resolved "https://registry.yarnpkg.com/@types/semver/-/semver-5.5.0.tgz#146c2a29ee7d3bae4bf2fcb274636e264c813c45"
@@ -282,6 +400,14 @@
   dependencies:
     "@types/node" "*"
 
+"@types/ws@^5.1.1":
+  version "5.1.2"
+  resolved "https://registry.yarnpkg.com/@types/ws/-/ws-5.1.2.tgz#f02d3b1cd46db7686734f3ce83bdf46c49decd64"
+  integrity sha512-NkTXUKTYdXdnPE2aUUbGOXE1XfMK527SCvU/9bj86kyFF6kZ9ZnOQ3mK5jADn98Y2vEUD/7wKDgZa7Qst2wYOg==
+  dependencies:
+    "@types/events" "*"
+    "@types/node" "*"
+
 JSONStream@^1.3.1:
   version "1.3.5"
   resolved "https://registry.yarnpkg.com/JSONStream/-/JSONStream-1.3.5.tgz#3208c1f08d3a4d99261ab64f92302bc15e111ca0"
@@ -629,6 +755,11 @@ assertion-error@^1.1.0:
   resolved "https://registry.yarnpkg.com/assertion-error/-/assertion-error-1.1.0.tgz#e60b6b0e8f301bd97e5375215bda406c85118c0b"
   integrity sha512-jgsaNduz+ndvGyFt3uSuWqvy4lCnIJiovtouQN5JZHOKCS2QuhEdbcQHFhVksz2N2U9hXJo8odG7ETyWlEeuDw==
 
+async-limiter@~1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/async-limiter/-/async-limiter-1.0.0.tgz#78faed8c3d074ab81f22b4e985d79e8738f720f8"
+  integrity sha512-jp/uFnooOiO+L211eZOoSyzpOITMXx1rBITauYykG3BRYPu8h0UcxsPNB04RR5vo4Tyz3+ay17tR6JVf9qzYWg==
+
 async-lock@^1.1.4:
   version "1.1.4"
   resolved "https://registry.yarnpkg.com/async-lock/-/async-lock-1.1.4.tgz#863aff9d5c243f75034349be7df9c3ceb7a54254"
@@ -654,6 +785,14 @@ aws4@^1.8.0:
   resolved "https://registry.yarnpkg.com/aws4/-/aws4-1.8.0.tgz#f0e003d9ca9e7f59c7a508945d7b2ef9a04a542f"
   integrity sha512-ReZxvNHIOv88FlT7rxcXIIC0fPt4KZqZbOlivyWtXLt8ESx84zd3kMC6iK5jVeS2qt+g7ftS7ye4fi06X5rtRQ==
 
+axios@^0.18.0:
+  version "0.18.1"
+  resolved "https://registry.yarnpkg.com/axios/-/axios-0.18.1.tgz#ff3f0de2e7b5d180e757ad98000f1081b87bcea3"
+  integrity sha512-0BfJq4NSfQXd+SkFdrvFbG7addhYSBA2mQwISr46pD6E5iqkWg02RAs8vyTT/j0RTnoYmeXauBuSv1qKwR179g==
+  dependencies:
+    follow-redirects "1.5.10"
+    is-buffer "^2.0.2"
+
 babel-code-frame@^6.22.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-code-frame/-/babel-code-frame-6.26.0.tgz#63fd43f7dc1e3bb7ce35947db8fe369a3f58c74b"
@@ -1041,19 +1180,19 @@ codechain-primitives@^1.0.0:
     rlp "^2.1.0"
 
 codechain-primitives@^1.0.1:
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/codechain-primitives/-/codechain-primitives-1.0.1.tgz#86b397ec379f52ae01daeaf74e29712083a48a87"
-  integrity sha512-XKgGwB9JzE3/43IEgroRHIjESJ4NiFc1Ee7qucqSuDhUx5DQtm4uQJreJvy5/rBcQMaDPTYcfx6UiavCfhx3+g==
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/codechain-primitives/-/codechain-primitives-1.0.2.tgz#2e44c7ba776dbe9d3473bf68c817572e0185a8a3"
+  integrity sha512-PSnXHIoR6EOhoMk4hjPttWGovcJXPYIgUj5De78Q3f5+yah6OPbJR4v82L+MCYOmD5+LvDF50mUzyOAAq+JNcg==
   dependencies:
     bignumber.js "^7.2.1"
     blakejs "^1.1.0"
     bn.js "^4.11.8"
     buffer "^5.2.1"
+    crypto-js "^3.1.9-1"
     elliptic "^6.4.1"
     hmac-drbg "^1.0.1"
     lodash "^4.17.11"
     node-forge "^0.7.6"
-    ripemd160 "^2.0.2"
     rlp "^2.1.0"
 
 codechain-sdk@^1.2.0:
@@ -1073,7 +1212,7 @@ codechain-sdk@^1.2.0:
 
 "codechain-stakeholder-sdk@https://github.com/majecty/codechain-stakeholder-sdk-js#dist":
   version "0.1.0"
-  resolved "https://github.com/majecty/codechain-stakeholder-sdk-js#625a96fea22363e6179e968fe963bbeac2ccd52f"
+  resolved "https://github.com/majecty/codechain-stakeholder-sdk-js#b55c5ed82672c023bcd60b6412281d450ac222db"
   dependencies:
     cli-table3 "^0.5.1"
     codechain-primitives "^1.0.1"
@@ -1252,6 +1391,11 @@ cross-spawn@^6.0.0:
     shebang-command "^1.2.0"
     which "^1.2.9"
 
+crypto-js@^3.1.9-1:
+  version "3.1.9-1"
+  resolved "https://registry.yarnpkg.com/crypto-js/-/crypto-js-3.1.9-1.tgz#fda19e761fc077e01ffbfdc6e9fdfc59e8806cd8"
+  integrity sha1-/aGedh/Ad+Af+/3G6f38WeiAbNg=
+
 cycle@1.0.x:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/cycle/-/cycle-1.0.3.tgz#21e80b2be8580f98b468f379430662b046c34ad2"
@@ -1285,6 +1429,13 @@ debug@3.2.6, debug@^3.0.1, debug@^3.1.0:
   dependencies:
     ms "^2.1.1"
 
+debug@=3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-3.1.0.tgz#5bb5a0672628b64149566ba16819e61518c67261"
+  integrity sha512-OX8XqP7/1a9cqkxYw2yXss15f26NKWBpDXQd0/uK/KPqdQhxbPa994hnzjcE2VqQpDslf55723cKPUOGSmMY3g==
+  dependencies:
+    ms "2.0.0"
+
 decamelize@^1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/decamelize/-/decamelize-1.2.0.tgz#f6534d15148269b20352e7bee26f501f9a191290"
@@ -1309,6 +1460,11 @@ deep-extend@^0.6.0:
   resolved "https://registry.yarnpkg.com/deep-extend/-/deep-extend-0.6.0.tgz#c4fa7c95404a17a9c3e8ca7e1537312b736330ac"
   integrity sha512-LOHxIOaPYdHlJRtCQfDIVZtfw/ufM8+rVj649RIHzcm/vGwQRXFt6OPqIFWsm2XEMrNIEtWR64sY1LEKD2vAOA==
 
+deepmerge@^2.1.1:
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/deepmerge/-/deepmerge-2.2.1.tgz#5d3ff22a01c00f645405a2fbc17d0778a1801170"
+  integrity sha512-R9hc1Xa/NOBi9WRVUWg19rl1UB7Tt4kuPd+thNJgFZoxXsTz7ncaPaeIm+40oSGuP33DfMb4sZt1QIGiJzC4EA==
+
 define-properties@^1.1.1, define-properties@^1.1.2:
   version "1.1.3"
   resolved "https://registry.yarnpkg.com/define-properties/-/define-properties-1.1.3.tgz#cf88da6cbee26fe6db7094f61d870cbd84cee9f1"
@@ -1565,6 +1721,11 @@ event-emitter@^0.3.5:
     d "1"
     es5-ext "~0.10.14"
 
+eventemitter3@^3.1.0:
+  version "3.1.2"
+  resolved "https://registry.yarnpkg.com/eventemitter3/-/eventemitter3-3.1.2.tgz#2d3d48f9c346698fce83a85d7d664e98535df6e7"
+  integrity sha512-tvtQIeLVHjDkJYnzf2dgVMxfuSGJeM/7UCG17TT4EumTfNtF+0nebF/4zWOIkCreAbtNqhGEboB6BWrwqNaw4Q==
+
 execa@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/execa/-/execa-1.0.0.tgz#c6236a5bb4df6d6f15e88e7f017798216749ddd8"
@@ -1688,6 +1849,11 @@ find-up@3.0.0, find-up@^3.0.0:
   dependencies:
     locate-path "^3.0.0"
 
+finity@^0.5.4:
+  version "0.5.4"
+  resolved "https://registry.yarnpkg.com/finity/-/finity-0.5.4.tgz#f2a8a9198e8286467328ec32c8bfcc19a2229c11"
+  integrity sha512-3l+5/1tuw616Lgb0QBimxfdd2TqaDGpfCBpfX6EqtFmqUV3FtQnVEX4Aa62DagYEqnsTIjZcTfbq9msDbXYgyA==
+
 flat@^4.1.0:
   version "4.1.0"
   resolved "https://registry.yarnpkg.com/flat/-/flat-4.1.0.tgz#090bec8b05e39cba309747f1d588f04dbaf98db2"
@@ -1700,6 +1866,13 @@ fmt@^1.1.0:
   resolved "https://registry.yarnpkg.com/fmt/-/fmt-1.1.0.tgz#e5f81ee412b1c9cf1f65ec9646d9eb27ce9a75a5"
   integrity sha512-RJcbgbg7MWnMijZnexn/SUXxz7pkOWBORoylniUUHzOyhT4aKdQ5oEXyXuXTQUbf/CcKArp3N5NpWMYlez25tw==
 
+follow-redirects@1.5.10:
+  version "1.5.10"
+  resolved "https://registry.yarnpkg.com/follow-redirects/-/follow-redirects-1.5.10.tgz#7b7a9f9aea2fdff36786a94ff643ed07f4ff5e2a"
+  integrity sha512-0V5l4Cizzvqt5D44aTXbFZz+FtyXV1vrDN6qrelxtfYQKW0KO0W2T/hkE8xvGa/540LkZlkaUjO4ailYTFtHVQ==
+  dependencies:
+    debug "=3.1.0"
+
 for-in@^0.1.3:
   version "0.1.8"
   resolved "https://registry.yarnpkg.com/for-in/-/for-in-0.1.8.tgz#d8773908e31256109952b1fdb9b3fa867d2775e1"
@@ -1731,6 +1904,15 @@ form-data@^2.3.1, form-data@~2.3.2:
     combined-stream "^1.0.6"
     mime-types "^2.1.12"
 
+form-data@^2.3.3:
+  version "2.5.0"
+  resolved "https://registry.yarnpkg.com/form-data/-/form-data-2.5.0.tgz#094ec359dc4b55e7d62e0db4acd76e89fe874d37"
+  integrity sha512-WXieX3G/8side6VIqx44ablyULoGruSde5PNTxoUyo5CeyAMX6nVWUd0rgist/EuX655cjhUhTo1Fo3tRYqbcA==
+  dependencies:
+    asynckit "^0.4.0"
+    combined-stream "^1.0.6"
+    mime-types "^2.1.12"
+
 format-util@^1.0.3:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/format-util/-/format-util-1.0.3.tgz#032dca4a116262a12c43f4c3ec8566416c5b2d95"
@@ -2047,7 +2229,7 @@ is-buffer@^1.1.5:
   resolved "https://registry.yarnpkg.com/is-buffer/-/is-buffer-1.1.6.tgz#efaa2ea9daa0d7ab2ea13a97b2b8ad51fefbe8be"
   integrity sha512-NcdALwpXkTm5Zvvbk7owOUSvVvBKDgKP5/ewfXEznmQFfs4ZRmanOeKBTjRVjka3QFoN6XJ+9F3USqfHqTaU5w==
 
-is-buffer@~2.0.3:
+is-buffer@^2.0.2, is-buffer@~2.0.3:
   version "2.0.3"
   resolved "https://registry.yarnpkg.com/is-buffer/-/is-buffer-2.0.3.tgz#4ecf3fcf749cbd1e472689e109ac66261a25e725"
   integrity sha512-U15Q7MXTuZlrbymiz95PJpZxu8IlipAp4dtS3wOdgPXx3mqBnslrWU14kxfHB+Py/+2PVKSr37dMAgM2A4uArw==
@@ -2877,6 +3059,11 @@ osenv@^0.1.4:
     os-homedir "^1.0.0"
     os-tmpdir "^1.0.0"
 
+p-cancelable@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/p-cancelable/-/p-cancelable-1.1.0.tgz#d078d15a3af409220c886f1d9a0ca2e441ab26cc"
+  integrity sha512-s73XxOZ4zpt1edZYZzvhqFa6uvQc1vwUa0K0BdtIZgQMAJj9IbebH+JkgKZc9h+B05PKHLOTl4ajG1BmNrVZlw==
+
 p-defer@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/p-defer/-/p-defer-1.0.0.tgz#9f6eb182f6c9aa8cd743004a7d4f96b196b0fb0c"
@@ -2906,6 +3093,19 @@ p-locate@^3.0.0:
   dependencies:
     p-limit "^2.0.0"
 
+p-queue@^2.4.2:
+  version "2.4.2"
+  resolved "https://registry.yarnpkg.com/p-queue/-/p-queue-2.4.2.tgz#03609826682b743be9a22dba25051bd46724fc34"
+  integrity sha512-n8/y+yDJwBjoLQe1GSJbbaYQLTI7QHNZI2+rpmCDbe++WLf9HC3gf6iqj5yfPAV71W4UF3ql5W1+UBPXoXTxng==
+
+p-retry@^4.0.0:
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/p-retry/-/p-retry-4.1.0.tgz#9ce7cef2069e84bf590df3b8ec18d740109338d6"
+  integrity sha512-oepllyG9gX1qH4Sm20YAKxg1GA7L7puhvGnTfimi31P07zSIj7SDV6YtuAx9nbJF51DES+2CIIRkXs8GKqWJxA==
+  dependencies:
+    "@types/retry" "^0.12.0"
+    retry "^0.12.0"
+
 p-try@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/p-try/-/p-try-2.0.0.tgz#85080bb87c64688fa47996fe8f7dfbe8211760b1"
@@ -3362,6 +3562,11 @@ retry-as-promised@^2.3.2:
     bluebird "^3.4.6"
     debug "^2.6.9"
 
+retry@^0.12.0:
+  version "0.12.0"
+  resolved "https://registry.yarnpkg.com/retry/-/retry-0.12.0.tgz#1b42a6266a21f07421d1b0b54b7dc167b01c013b"
+  integrity sha1-G0KmJmoh8HQh0bC1S33BZ7AcATs=
+
 ripemd160@^2.0.2:
   version "2.0.2"
   resolved "https://registry.yarnpkg.com/ripemd160/-/ripemd160-2.0.2.tgz#a1c1a6f624751577ba5d07914cbc92850585890c"
@@ -4204,6 +4409,13 @@ wrappy@1:
   resolved "https://registry.yarnpkg.com/wrappy/-/wrappy-1.0.2.tgz#b5243d8f3ec1aa35f1364605bc0d1036e30ab69f"
   integrity sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=
 
+ws@^5.2.0:
+  version "5.2.2"
+  resolved "https://registry.yarnpkg.com/ws/-/ws-5.2.2.tgz#dffef14866b8e8dc9133582514d1befaf96e980f"
+  integrity sha512-jaHFD6PFv6UgoIVda6qZllptQsMlDEJkTQcybzzXDYM1XO9Y8em691FGMPmM46WGyLU4z9KMgQN+qrux/nhlHA==
+  dependencies:
+    async-limiter "~1.0.0"
+
 xtend@^4.0.0:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/xtend/-/xtend-4.0.1.tgz#a5c6d532be656e23db820efb943a1f04998d63af"