diff --git a/dist/generators.d.ts b/dist/generators.d.ts
deleted file mode 100644
index 2d89c70..0000000
--- a/dist/generators.d.ts
+++ /dev/null
@@ -1,20 +0,0 @@
-import { GeneratorOptions } from ".";
-import { PackageInfo, RequiredProps } from "./utils";
-declare global {
-    interface String {
-        padEnd<T extends string>(maxLength: number, fillString?: string): T;
-    }
-}
-export declare type UserScriptManagerName = "tampermonkey" | "violentmonkey" | "greasemonkey";
-export declare type GrantOptions = "get" | "set" | "list" | "delete" | "unsafe" | "close" | "focus" | "change";
-declare type CommonGrants = "none";
-export declare type GreasemonkeyGrants = CommonGrants | "GM.setValue" | "GM.getValue" | "GM.listValues" | "GM.deleteValue";
-export declare type TampermonkeyGrants = CommonGrants | "GM_setValue" | "GM_getValue" | "GM_listValues" | "GM_deleteValue" | "unsafeWindow" | "window.close" | "window.focus" | "window.onurlchange";
-export declare type HeaderGenerator = (info: PackageInfo, options: RequiredProps<GeneratorOptions, "spaces">) => string;
-export declare type GeneratorMap = {
-    [P in UserScriptManagerName]: HeaderGenerator;
-};
-export declare const generateGreasemnonkeyHeaders: HeaderGenerator;
-export declare const generateTampermonkeyHeaders: HeaderGenerator;
-export declare const generateViolentMonkeyHeaders: HeaderGenerator;
-export {};
diff --git a/dist/generators.js b/dist/generators.js
deleted file mode 100644
index c2dbdf4..0000000
--- a/dist/generators.js
+++ /dev/null
@@ -1,70 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.generateViolentMonkeyHeaders = exports.generateTampermonkeyHeaders = exports.generateGreasemnonkeyHeaders = void 0;
-const utils_1 = require("./utils");
-const makeMonkeyTags = (name = "UserScript") => [
-    `// ==${name}==`,
-    `// ==/${name}==`,
-];
-const makeMonkeyHeader = ([name, value]) => (value ? `// @${name} ${value}` : `// @${name}`);
-const generateGreasemnonkeyHeaders = () => {
-    const [openTag, closeTag] = makeMonkeyTags();
-    const headers = [];
-    const parsedHeaders = headers.map(makeMonkeyHeader);
-    return `
-${openTag}
-${parsedHeaders.join("\n")}
-${closeTag}
-`;
-};
-exports.generateGreasemnonkeyHeaders = generateGreasemnonkeyHeaders;
-const LN = "\n";
-const generateTampermonkeyHeaders = ({ author, contributors = [], icon, name, description, homepage, bugs: { url: supportURL }, repository: { url: source }, version, }, { spaces, matches = [], grants = [] }) => {
-    const [openTag, closeTag] = makeMonkeyTags();
-    const parsedAuthor = utils_1.parseAuthor(author);
-    const { packageName, scope } = utils_1.parseName(name);
-    const matchHeaders = matches.map((uri) => ["match", uri]);
-    const grantMap = {
-        set: "GM_setValue",
-        get: "GM_getValue",
-        delete: "GM_deleteValue",
-        list: "GM_listValues",
-        unsafe: "unsafeWindow",
-        change: "window.onurlchange",
-        close: "window.close",
-        focus: "window.focus",
-    };
-    const grantHeaders = grants.map((grant) => ["grant", grantMap[grant]]);
-    if (!grantHeaders.length)
-        grantHeaders.push(["grant", "none"]);
-    const headers = [
-        ["author", utils_1.formatAuthor(parsedAuthor)],
-        ["description", description],
-        ["homepage", homepage],
-        ...matchHeaders,
-        ...grantHeaders,
-        ["name", packageName],
-        ["source", source],
-        ["supportURL", supportURL],
-        ["version", version],
-    ];
-    if (scope)
-        headers.push(["namespace", scope]);
-    if (icon)
-        headers.push(["icon", icon]);
-    if (contributors.length) {
-        const formatted = contributors.map((contributor) => utils_1.formatAuthor(utils_1.parseAuthor(contributor)));
-        headers.push(["contributors", formatted.join(", ")]);
-    }
-    const longest = utils_1.getLongest(headers.map(([key]) => key)) + spaces;
-    const indentedHeaders = headers.map(([key, val]) => [key.padEnd(longest), val]);
-    const parsedHeaders = indentedHeaders
-        .map(makeMonkeyHeader)
-        .sort();
-    return [openTag, ...parsedHeaders, closeTag].join(LN);
-};
-exports.generateTampermonkeyHeaders = generateTampermonkeyHeaders;
-const generateViolentMonkeyHeaders = ({}) => {
-    return "";
-};
-exports.generateViolentMonkeyHeaders = generateViolentMonkeyHeaders;
diff --git a/dist/generators/common/monkey.d.ts b/dist/generators/common/monkey.d.ts
new file mode 100644
index 0000000..05c98ea
--- /dev/null
+++ b/dist/generators/common/monkey.d.ts
@@ -0,0 +1,31 @@
+import { HeaderEntries, HeaderEntry } from "..";
+export declare type MonkeyHeader = `// @${string} ${string}` | `// @${string}`;
+export declare const makeMonkeyTags: (name?: string) => readonly [openTag: string, closeTag: string];
+export declare const makeMonkeyHeader: <T extends {
+    description: string;
+    exclude: string[];
+    icon: string;
+    include: string[];
+    match: string[];
+    name: string;
+    namespace: string;
+    noframes: "";
+    resource: string[];
+    require: string[];
+    version: `${number}.${number}.${number}`;
+    grant: string;
+}>([name, value,]: HeaderEntry<T>) => MonkeyHeader;
+export declare const finalizeMonkeyHeaders: <T extends {
+    description: string;
+    exclude: string[];
+    icon: string;
+    include: string[];
+    match: string[];
+    name: string;
+    namespace: string;
+    noframes: "";
+    resource: string[];
+    require: string[];
+    version: `${number}.${number}.${number}`;
+    grant: string;
+}>(headers: HeaderEntries<T>, spaces: number) => string;
diff --git a/dist/generators/common/monkey.js b/dist/generators/common/monkey.js
new file mode 100644
index 0000000..5975421
--- /dev/null
+++ b/dist/generators/common/monkey.js
@@ -0,0 +1,24 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.finalizeMonkeyHeaders = exports.makeMonkeyHeader = exports.makeMonkeyTags = void 0;
+const common_1 = require("../../utils/common");
+const makeMonkeyTags = (name = "UserScript") => [
+    `// ==${name}==`,
+    `// ==/${name}==`,
+];
+exports.makeMonkeyTags = makeMonkeyTags;
+const makeMonkeyHeader = ([name, value,]) => (value ? `// @${name} ${value}` : `// @${name}`);
+exports.makeMonkeyHeader = makeMonkeyHeader;
+const finalizeMonkeyHeaders = (headers, spaces) => {
+    const [openTag, closeTag] = exports.makeMonkeyTags();
+    const longest = common_1.getLongest(headers.map(([key]) => key)) + spaces;
+    const indentedHeaders = headers.map(([key, val]) => [
+        key.padEnd(longest),
+        val,
+    ]);
+    const parsedHeaders = indentedHeaders
+        .map(exports.makeMonkeyHeader)
+        .sort();
+    return [openTag, ...parsedHeaders, closeTag].join("\n");
+};
+exports.finalizeMonkeyHeaders = finalizeMonkeyHeaders;
diff --git a/dist/generators/greasemonkey/index.d.ts b/dist/generators/greasemonkey/index.d.ts
new file mode 100644
index 0000000..2f8f6ff
--- /dev/null
+++ b/dist/generators/greasemonkey/index.d.ts
@@ -0,0 +1,3 @@
+import { HeaderGenerator } from "..";
+import { GreasemonkeyGrantOptions } from "./types";
+export declare const generateGreasemonkeyHeaders: HeaderGenerator<GreasemonkeyGrantOptions>;
diff --git a/dist/generators/greasemonkey/index.js b/dist/generators/greasemonkey/index.js
new file mode 100644
index 0000000..63c5aa7
--- /dev/null
+++ b/dist/generators/greasemonkey/index.js
@@ -0,0 +1,25 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.generateGreasemonkeyHeaders = void 0;
+const __1 = require("..");
+const monkey_1 = require("../common/monkey");
+const generateGreasemonkeyHeaders = (_packageInfo, { matches = [], grants = [] }) => {
+    const grantMap = {
+        set: "GM.setValue",
+        get: "GM.getValue",
+        delete: "GM.deleteValue",
+        list: "GM.listValues",
+        notify: "GM.notification",
+        clip: "GM.setClipboard",
+        fetch: "GM.xmlHttpRequest",
+        unsafe: "unsafeWindow",
+    };
+    const matchHeaders = __1.generateMatchHeaders(matches);
+    const grantHeaders = __1.generateGrantHeaders(grantMap, grants);
+    const headers = [
+        ...grantHeaders,
+        ...matchHeaders,
+    ];
+    return monkey_1.finalizeMonkeyHeaders(headers, 4);
+};
+exports.generateGreasemonkeyHeaders = generateGreasemonkeyHeaders;
diff --git a/dist/generators/greasemonkey/types.d.ts b/dist/generators/greasemonkey/types.d.ts
new file mode 100644
index 0000000..132c2f8
--- /dev/null
+++ b/dist/generators/greasemonkey/types.d.ts
@@ -0,0 +1,7 @@
+import { CommonGrantOptions, CommonGrants, CommonHeaders, CommonRunAt, CustomHeaders } from "..";
+export declare type GreasemonkeyGrantOptions = CommonGrantOptions | "notify" | "clip" | "fetch";
+export declare type GreasemonkeyGrants = CommonGrants | "GM.setValue" | "GM.getValue" | "GM.listValues" | "GM.deleteValue" | "GM.notification" | "GM.setClipboard" | "GM.xmlHttpRequest";
+export declare type GreasemonkeyHeaders = CustomHeaders & CommonHeaders<{
+    "grant": GreasemonkeyGrants;
+    "run-at": CommonRunAt;
+}>;
diff --git a/dist/generators/greasemonkey/types.js b/dist/generators/greasemonkey/types.js
new file mode 100644
index 0000000..ce03781
--- /dev/null
+++ b/dist/generators/greasemonkey/types.js
@@ -0,0 +1,2 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/dist/generators/index.d.ts b/dist/generators/index.d.ts
new file mode 100644
index 0000000..2240cea
--- /dev/null
+++ b/dist/generators/index.d.ts
@@ -0,0 +1,63 @@
+import { GeneratorOptions } from "..";
+import { RequiredProps } from "../utils/common";
+import { PackageInfo } from "../utils/package";
+import { GreasemonkeyGrantOptions } from "./greasemonkey/types";
+import { TampermonkeyGrantOptions } from "./tampermonkey/types";
+declare global {
+    interface String {
+        padEnd<T extends string>(maxLength: number, fillString?: string): T;
+    }
+}
+export declare type CommonGrantOptions = "get" | "set" | "list" | "delete" | "unsafe";
+export declare type GrantOptions = GreasemonkeyGrantOptions | TampermonkeyGrantOptions | CommonGrantOptions;
+export declare type UserScriptManagerName = "tampermonkey" | "violentmonkey" | "greasemonkey";
+export declare type CommonGrants = "none" | "unsafeWindow";
+export declare type CommonRunAt = "document-start" | "document-end" | "document-idle";
+export declare type HeaderGenerator<T extends GrantOptions> = (info: PackageInfo, options: RequiredProps<GeneratorOptions<T>, "spaces">) => string;
+export declare type CommonHeaders<T extends object = {}> = T & {
+    description: string;
+    exclude: string[];
+    icon: string;
+    include: string[];
+    match: string[];
+    name: string;
+    namespace: string;
+    noframes: "";
+    resource: string[];
+    require: string[];
+    version: `${number}.${number}.${number}`;
+    grant: string;
+};
+export declare type CustomHeaders = {
+    contributors: string;
+};
+export declare type HeaderEntry<T> = [keyof T & string, string];
+export declare type HeaderEntries<T> = HeaderEntry<T>[];
+export declare const generateGrantHeaders: <T extends {
+    description: string;
+    exclude: string[];
+    icon: string;
+    include: string[];
+    match: string[];
+    name: string;
+    namespace: string;
+    noframes: "";
+    resource: string[];
+    require: string[];
+    version: `${number}.${number}.${number}`;
+    grant: string;
+}, U extends GrantOptions>(grantMap: Record<U, T["grant"]>, grants: U[]) => HeaderEntries<T>;
+export declare const generateMatchHeaders: <T extends {
+    description: string;
+    exclude: string[];
+    icon: string;
+    include: string[];
+    match: string[];
+    name: string;
+    namespace: string;
+    noframes: "";
+    resource: string[];
+    require: string[];
+    version: `${number}.${number}.${number}`;
+    grant: string;
+}>(matches: string[]) => HeaderEntries<T>;
diff --git a/dist/generators/index.js b/dist/generators/index.js
new file mode 100644
index 0000000..d613650
--- /dev/null
+++ b/dist/generators/index.js
@@ -0,0 +1,17 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.generateMatchHeaders = exports.generateGrantHeaders = void 0;
+const generateGrantHeaders = (grantMap, grants) => {
+    const grantHeaders = grants.map((grant) => [
+        "grant",
+        grantMap[grant],
+    ]);
+    return grantHeaders.length
+        ? grantHeaders
+        : [["grant", "none"]];
+};
+exports.generateGrantHeaders = generateGrantHeaders;
+const generateMatchHeaders = (matches) => {
+    return matches.map((uri) => ["match", uri]);
+};
+exports.generateMatchHeaders = generateMatchHeaders;
diff --git a/dist/generators/tampermonkey/index.d.ts b/dist/generators/tampermonkey/index.d.ts
new file mode 100644
index 0000000..3f2811b
--- /dev/null
+++ b/dist/generators/tampermonkey/index.d.ts
@@ -0,0 +1,3 @@
+import { HeaderGenerator } from "..";
+import { TampermonkeyGrantOptions } from "./types";
+export declare const generateTampermonkeyHeaders: HeaderGenerator<TampermonkeyGrantOptions>;
diff --git a/dist/generators/tampermonkey/index.js b/dist/generators/tampermonkey/index.js
new file mode 100644
index 0000000..98b2021
--- /dev/null
+++ b/dist/generators/tampermonkey/index.js
@@ -0,0 +1,44 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.generateTampermonkeyHeaders = void 0;
+const __1 = require("..");
+const author_1 = require("../../utils/author");
+const common_1 = require("../../utils/common");
+const monkey_1 = require("../common/monkey");
+const generateTampermonkeyHeaders = ({ author, contributors = [], icon, name, description, homepage, bugs: { url: supportURL }, repository: { url: source }, version, }, { spaces, matches = [], grants = [] }) => {
+    const parsedAuthor = author_1.parseAuthor(author);
+    const { packageName, scope } = common_1.parseName(name);
+    const matchHeaders = __1.generateMatchHeaders(matches);
+    const grantMap = {
+        set: "GM_setValue",
+        get: "GM_getValue",
+        delete: "GM_deleteValue",
+        list: "GM_listValues",
+        unsafe: "unsafeWindow",
+        change: "window.onurlchange",
+        close: "window.close",
+        focus: "window.focus",
+    };
+    const grantHeaders = __1.generateGrantHeaders(grantMap, grants);
+    const headers = [
+        ["author", author_1.formatAuthor(parsedAuthor)],
+        ["description", description],
+        ["homepage", homepage],
+        ...matchHeaders,
+        ...grantHeaders,
+        ["name", packageName],
+        ["source", source],
+        ["supportURL", supportURL],
+        ["version", version],
+    ];
+    if (scope)
+        headers.push(["namespace", scope]);
+    if (icon)
+        headers.push(["icon", icon]);
+    if (contributors.length) {
+        const formatted = contributors.map((contributor) => author_1.formatAuthor(author_1.parseAuthor(contributor)));
+        headers.push(["contributors", formatted.join(", ")]);
+    }
+    return monkey_1.finalizeMonkeyHeaders(headers, spaces);
+};
+exports.generateTampermonkeyHeaders = generateTampermonkeyHeaders;
diff --git a/dist/generators/tampermonkey/types.d.ts b/dist/generators/tampermonkey/types.d.ts
new file mode 100644
index 0000000..586a00e
--- /dev/null
+++ b/dist/generators/tampermonkey/types.d.ts
@@ -0,0 +1,23 @@
+import { CommonGrantOptions, CommonGrants, CommonHeaders, CommonRunAt, CustomHeaders } from "..";
+export declare type TampermonkeyGrantOptions = CommonGrantOptions | "close" | "focus" | "change";
+export declare type TampermonkeyGrants = CommonGrants | "GM_setValue" | "GM_getValue" | "GM_listValues" | "GM_deleteValue" | "window.close" | "window.focus" | "window.onurlchange";
+export declare type TampermonkeyHeaders = CustomHeaders & CommonHeaders<{
+    "author": string;
+    "homepage": string;
+    "homepageURL": string;
+    "website": string;
+    "source": string;
+    "iconURL": string;
+    "defaulticon": string;
+    "icon64": string;
+    "icon64URL": string;
+    "updateURL": string;
+    "downloadURL": string;
+    "supportURL": string;
+    "connect": string[];
+    "run-at": CommonRunAt | "context-menu" | "document-body";
+    "grant": TampermonkeyGrants;
+    "antifeature": `${"ads" | "tracking" | "miner"} ${string}`[];
+    "unwrap": "";
+    "nocompat": "Chrome" | "Opera" | "FireFox";
+}>;
diff --git a/dist/generators/tampermonkey/types.js b/dist/generators/tampermonkey/types.js
new file mode 100644
index 0000000..ce03781
--- /dev/null
+++ b/dist/generators/tampermonkey/types.js
@@ -0,0 +1,2 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/dist/generators/violentmonkey/index.d.ts b/dist/generators/violentmonkey/index.d.ts
new file mode 100644
index 0000000..207b9b9
--- /dev/null
+++ b/dist/generators/violentmonkey/index.d.ts
@@ -0,0 +1,2 @@
+import { CommonGrantOptions, HeaderGenerator } from "..";
+export declare const generateViolentMonkeyHeaders: HeaderGenerator<CommonGrantOptions>;
diff --git a/dist/generators/violentmonkey/index.js b/dist/generators/violentmonkey/index.js
new file mode 100644
index 0000000..d3268d7
--- /dev/null
+++ b/dist/generators/violentmonkey/index.js
@@ -0,0 +1,9 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.generateViolentMonkeyHeaders = void 0;
+const monkey_1 = require("../common/monkey");
+const generateViolentMonkeyHeaders = ({}) => {
+    const headers = [];
+    return monkey_1.finalizeMonkeyHeaders(headers, 4);
+};
+exports.generateViolentMonkeyHeaders = generateViolentMonkeyHeaders;
diff --git a/dist/generators/violentmonkey/types.d.ts b/dist/generators/violentmonkey/types.d.ts
new file mode 100644
index 0000000..0bd770d
--- /dev/null
+++ b/dist/generators/violentmonkey/types.d.ts
@@ -0,0 +1,2 @@
+import { CommonHeaders, CustomHeaders } from "..";
+export declare type ViolentMonkeyHeaders = CustomHeaders & CommonHeaders<{}>;
diff --git a/dist/generators/violentmonkey/types.js b/dist/generators/violentmonkey/types.js
new file mode 100644
index 0000000..ce03781
--- /dev/null
+++ b/dist/generators/violentmonkey/types.js
@@ -0,0 +1,2 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/dist/index.d.ts b/dist/index.d.ts
index 4d93d74..e1f1c07 100644
--- a/dist/index.d.ts
+++ b/dist/index.d.ts
@@ -1,10 +1,10 @@
 import { GrantOptions, UserScriptManagerName } from "./generators";
-export declare type GeneratorOptions = {
+export declare type GeneratorOptions<T extends GrantOptions> = {
     packagePath: string;
     output: string;
     spaces?: number;
     matches?: string[];
-    grants?: GrantOptions[];
+    grants?: T[];
     direct?: boolean;
 };
-export declare const generate: (type: UserScriptManagerName, { packagePath, output, spaces, direct, ...rest }: GeneratorOptions) => Promise<string>;
+export declare const generate: <T extends GrantOptions>(type: UserScriptManagerName, { packagePath, output, spaces, direct, matches, ...rest }: GeneratorOptions<T>) => Promise<string>;
diff --git a/dist/index.js b/dist/index.js
index 84d6709..58ed0e1 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -6,27 +6,37 @@ const chalk_1 = require("chalk");
 const promises_1 = require("fs/promises");
 const yargs = require("yargs");
 const helpers_1 = require("yargs/helpers");
-const generators_1 = require("./generators");
-const utils_1 = require("./utils");
+const greasemonkey_1 = require("./generators/greasemonkey");
+const tampermonkey_1 = require("./generators/tampermonkey");
+const violentmonkey_1 = require("./generators/violentmonkey");
+const common_1 = require("./utils/common");
+const package_1 = require("./utils/package");
+const validators_1 = require("./utils/validators");
 const names = [
     "greasemonkey",
     "tampermonkey",
     "violentmonkey",
 ];
-const generate = async (type, { packagePath, output, spaces = 4, direct = false, ...rest }) => {
+const generate = async (type, { packagePath, output, spaces = 4, direct = false, matches = [], ...rest }) => {
     const managerTypeMap = {
-        greasemonkey: generators_1.generateGreasemnonkeyHeaders,
-        tampermonkey: generators_1.generateTampermonkeyHeaders,
-        violentmonkey: generators_1.generateViolentMonkeyHeaders,
+        greasemonkey: greasemonkey_1.generateGreasemonkeyHeaders,
+        tampermonkey: tampermonkey_1.generateTampermonkeyHeaders,
+        violentmonkey: violentmonkey_1.generateViolentMonkeyHeaders,
     };
     try {
-        const parsedPackage = await utils_1.getPackage(packagePath);
+        const parsedPackage = await package_1.getPackage(packagePath);
         if (!parsedPackage) {
             console.log(chalk_1.bgRed `missing or corrupted package`);
             return "";
         }
-        const content = managerTypeMap[type](parsedPackage, {
+        const { invalid, status, valid } = validators_1.validateMatchHeaders(matches);
+        if (!status) {
+            console.log(chalk_1.bgRed `Invalid @match headers:\n` + invalid.join("\n"));
+        }
+        const handler = managerTypeMap[type];
+        const content = handler(parsedPackage, {
             ...rest,
+            matches: valid,
             spaces,
             packagePath,
             output,
@@ -82,7 +92,7 @@ const sharedOpts = {
         type: "number",
     },
 };
-names.forEach((name) => cli.command(name, `generates ${utils_1.scase(name)} headers`, sharedOpts, ({ d, g = [], m = [], o, p, s }) => exports.generate(name, {
+names.forEach((name) => cli.command(name, `generates ${common_1.scase(name)} headers`, sharedOpts, ({ d, g = [], m = [], o, p, s }) => exports.generate(name, {
     direct: !!d,
     matches: m.map(String),
     grants: g,
diff --git a/dist/utils.d.ts b/dist/utils.d.ts
deleted file mode 100644
index e669d46..0000000
--- a/dist/utils.d.ts
+++ /dev/null
@@ -1,36 +0,0 @@
-export declare type RequiredProps<T, K extends keyof T = keyof T> = T & {
-    [P in K]-?: T[P];
-};
-declare type PackagePerson = string | {
-    name: string;
-    email?: string;
-    url?: string;
-};
-export declare type PackageInfo = {
-    author: PackagePerson;
-    contributors?: PackagePerson[];
-    icon?: string;
-    license: string;
-    homepage: string;
-    name: string;
-    version: `${number}.${number}.${number}`;
-    description: string;
-    bugs: {
-        url: string;
-    };
-    repository: {
-        type: "git" | "https";
-        url: string;
-    };
-};
-export declare const getPackage: (path: string) => Promise<PackageInfo | null>;
-export declare const getLongest: (words: string[]) => number;
-export declare const scase: (text: string) => string;
-export declare const mdLink: (lbl: string, href: string) => string;
-export declare const formatAuthor: ({ name, email, url, }: Exclude<PackageInfo["author"], string>) => string;
-export declare const parseAuthor: (info: PackageInfo["author"]) => Exclude<PackageInfo["author"], string>;
-export declare const parseName: (name: string) => {
-    scope: string;
-    packageName: string;
-};
-export {};
diff --git a/dist/utils.js b/dist/utils.js
deleted file mode 100644
index 717b827..0000000
--- a/dist/utils.js
+++ /dev/null
@@ -1,42 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.parseName = exports.parseAuthor = exports.formatAuthor = exports.mdLink = exports.scase = exports.getLongest = exports.getPackage = void 0;
-const promises_1 = require("fs/promises");
-const getPackage = async (path) => {
-    try {
-        const contents = await promises_1.readFile(path, { encoding: "utf-8" });
-        return JSON.parse(contents);
-    }
-    catch (error) {
-        return null;
-    }
-};
-exports.getPackage = getPackage;
-const getLongest = (words) => Math.max(...words.map(({ length }) => length));
-exports.getLongest = getLongest;
-const scase = (text) => `${text[0].toUpperCase()}${text.slice(1).toLowerCase()}`;
-exports.scase = scase;
-const mdLink = (lbl, href) => `[${lbl}](${href})`;
-exports.mdLink = mdLink;
-const formatAuthor = ({ name, email, url, }) => name + (email ? ` <${email}>` : "") + (url ? ` (${url})` : "");
-exports.formatAuthor = formatAuthor;
-const parseAuthor = (info) => {
-    if (typeof info === "object")
-        return info;
-    const authorRegex = /(\w+(?:\s\w+)?)(?:\s<(.+?)>)?(?:\s\((.+?)\))?$/i;
-    const match = authorRegex.exec(info);
-    if (!match)
-        throw new Error(`unable to parse author field: ${info}`);
-    const [_full, name, email, url] = match;
-    return {
-        name,
-        email,
-        url,
-    };
-};
-exports.parseAuthor = parseAuthor;
-const parseName = (name) => {
-    const [, scope, packageName] = name.match(/(?:@([\w-]+)\/)?([\w-]+)/) || [];
-    return { scope, packageName };
-};
-exports.parseName = parseName;
diff --git a/dist/utils/author.d.ts b/dist/utils/author.d.ts
new file mode 100644
index 0000000..a6a2334
--- /dev/null
+++ b/dist/utils/author.d.ts
@@ -0,0 +1,3 @@
+import { PackageInfo } from "./package";
+export declare const formatAuthor: ({ name, email, url, }: Exclude<PackageInfo["author"], string>) => string;
+export declare const parseAuthor: (info: PackageInfo["author"]) => Exclude<PackageInfo["author"], string>;
diff --git a/dist/utils/author.js b/dist/utils/author.js
new file mode 100644
index 0000000..0f85b2d
--- /dev/null
+++ b/dist/utils/author.js
@@ -0,0 +1,20 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.parseAuthor = exports.formatAuthor = void 0;
+const formatAuthor = ({ name, email, url, }) => name + (email ? ` <${email}>` : "") + (url ? ` (${url})` : "");
+exports.formatAuthor = formatAuthor;
+const parseAuthor = (info) => {
+    if (typeof info === "object")
+        return info;
+    const authorRegex = /(\w+(?:\s\w+)?)(?:\s<(.+?)>)?(?:\s\((.+?)\))?$/i;
+    const match = authorRegex.exec(info);
+    if (!match)
+        throw new Error(`unable to parse author field: ${info}`);
+    const [_full, name, email, url] = match;
+    return {
+        name,
+        email,
+        url,
+    };
+};
+exports.parseAuthor = parseAuthor;
diff --git a/dist/utils/common.d.ts b/dist/utils/common.d.ts
new file mode 100644
index 0000000..88b53e6
--- /dev/null
+++ b/dist/utils/common.d.ts
@@ -0,0 +1,10 @@
+export declare type RequiredProps<T, K extends keyof T = keyof T> = T & {
+    [P in K]-?: T[P];
+};
+export declare const getLongest: (words: string[]) => number;
+export declare const scase: (text: string) => string;
+export declare const mdLink: (lbl: string, href: string) => string;
+export declare const parseName: (name: string) => {
+    scope: string;
+    packageName: string;
+};
diff --git a/dist/utils/common.js b/dist/utils/common.js
new file mode 100644
index 0000000..bcaf521
--- /dev/null
+++ b/dist/utils/common.js
@@ -0,0 +1,14 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.parseName = exports.mdLink = exports.scase = exports.getLongest = void 0;
+const getLongest = (words) => Math.max(...words.map(({ length }) => length));
+exports.getLongest = getLongest;
+const scase = (text) => `${text[0].toUpperCase()}${text.slice(1).toLowerCase()}`;
+exports.scase = scase;
+const mdLink = (lbl, href) => `[${lbl}](${href})`;
+exports.mdLink = mdLink;
+const parseName = (name) => {
+    const [, scope, packageName] = name.match(/(?:@([\w-]+)\/)?([\w-]+)/) || [];
+    return { scope, packageName };
+};
+exports.parseName = parseName;
diff --git a/dist/utils/package.d.ts b/dist/utils/package.d.ts
new file mode 100644
index 0000000..0c3a51f
--- /dev/null
+++ b/dist/utils/package.d.ts
@@ -0,0 +1,23 @@
+export declare type PackagePerson = string | {
+    name: string;
+    email?: string;
+    url?: string;
+};
+export declare type PackageInfo = {
+    author: PackagePerson;
+    contributors?: PackagePerson[];
+    icon?: string;
+    license: string;
+    homepage: string;
+    name: string;
+    version: `${number}.${number}.${number}`;
+    description: string;
+    bugs: {
+        url: string;
+    };
+    repository: {
+        type: "git" | "https";
+        url: string;
+    };
+};
+export declare const getPackage: (path: string) => Promise<PackageInfo | null>;
diff --git a/dist/utils/package.js b/dist/utils/package.js
new file mode 100644
index 0000000..2e397d7
--- /dev/null
+++ b/dist/utils/package.js
@@ -0,0 +1,14 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.getPackage = void 0;
+const promises_1 = require("fs/promises");
+const getPackage = async (path) => {
+    try {
+        const contents = await promises_1.readFile(path, { encoding: "utf-8" });
+        return JSON.parse(contents);
+    }
+    catch (error) {
+        return null;
+    }
+};
+exports.getPackage = getPackage;
diff --git a/dist/utils/types.d.ts b/dist/utils/types.d.ts
new file mode 100644
index 0000000..f67b137
--- /dev/null
+++ b/dist/utils/types.d.ts
@@ -0,0 +1,3 @@
+export declare type RequiredOnly<T> = {
+    [K in keyof T as T[K] extends Required<T>[K] ? K : never]: T[K];
+};
diff --git a/dist/utils/types.js b/dist/utils/types.js
new file mode 100644
index 0000000..ce03781
--- /dev/null
+++ b/dist/utils/types.js
@@ -0,0 +1,2 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/dist/utils/validators.d.ts b/dist/utils/validators.d.ts
new file mode 100644
index 0000000..1c69f29
--- /dev/null
+++ b/dist/utils/validators.d.ts
@@ -0,0 +1,12 @@
+import { PackageInfo } from "./package";
+export declare const validateMatchHeaders: (matches: string[]) => {
+    invalid: string[];
+    status: boolean;
+    valid: string[];
+};
+export declare const validateRequiredHeaders: (packageInfo: PackageInfo) => {
+    status: boolean;
+    isValidVersion: boolean;
+    isValidHomepage: boolean;
+    missing: ("description" | "name" | "version" | "author" | "homepage" | "bugs" | "repository" | "license")[];
+};
diff --git a/dist/utils/validators.js b/dist/utils/validators.js
new file mode 100644
index 0000000..a7838a6
--- /dev/null
+++ b/dist/utils/validators.js
@@ -0,0 +1,36 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.validateRequiredHeaders = exports.validateMatchHeaders = void 0;
+const semver_1 = require("semver");
+const validator_1 = require("validator");
+const validateMatchHeaders = (matches) => {
+    const validationRegex = /^((?:https?|file|ftp|\*)(?=:\/\/)|(?:urn(?=:))):(?:\/\/)?(?:((?:\*||.+?)(?=\/|$)))?(\/\*|(?:.+?\*?)+)?|<all_urls>/;
+    const invalid = matches.filter((match) => !validationRegex.test(match));
+    return {
+        invalid,
+        status: !invalid.length,
+        valid: matches.filter((m) => !invalid.includes(m)),
+    };
+};
+exports.validateMatchHeaders = validateMatchHeaders;
+const validateRequiredHeaders = (packageInfo) => {
+    const required = [
+        "author",
+        "name",
+        "homepage",
+        "version",
+        "description",
+    ];
+    const missing = required.filter((p) => !(p in packageInfo));
+    const { homepage, version } = packageInfo;
+    const isValidVersion = !!semver_1.valid(version);
+    const isValidHomepage = validator_1.default.isURL(homepage);
+    const status = [isValidVersion, isValidHomepage, !missing.length].reduce((a, c) => a && c);
+    return {
+        status,
+        isValidVersion,
+        isValidHomepage,
+        missing,
+    };
+};
+exports.validateRequiredHeaders = validateRequiredHeaders;
diff --git a/src/generators/index.ts b/src/generators/index.ts
index 930cbd8..9484114 100644
--- a/src/generators/index.ts
+++ b/src/generators/index.ts
@@ -59,9 +59,9 @@ export const generateGrantHeaders = <
     T extends CommonHeaders,
     U extends GrantOptions
 >(
-    grantMap: Record<U, T["grant"]>,
-    grants: U[]
-) => {
+        grantMap: Record<U, T["grant"]>,
+        grants: U[]
+    ) => {
     const grantHeaders: HeaderEntries<T> = grants.map((grant) => [
         "grant",
         grantMap[grant],