diff --git a/packages/cli/README.md b/packages/cli/README.md
index 867cc1f..c7286a0 100644
--- a/packages/cli/README.md
+++ b/packages/cli/README.md
@@ -10,8 +10,18 @@ npm install --save-dev @bundle-analyzer/cli
 
 ## Usage
 
-```js
-webpack --json | bundle-analyzer --token <your-token>
+```
+Usage: bundle-analyzer [options] <stats>
+
+Options:
+  -V, --version               output the version number
+  --token <repository-token>  specify the repository token
+  --config-file <file>        specify a custom config file
+  -h, --help                  output usage information
+
+  Examples:
+    webpack --json | bundle-analyzer --token "your-repository-token"
+    cat webpack-stats.json | bundle-analyzer --token "your-repository-token"
 ```
 
 ## Complete documentation
diff --git a/packages/cli/src/index.js b/packages/cli/src/index.js
index bd97dc7..c2b5b8a 100644
--- a/packages/cli/src/index.js
+++ b/packages/cli/src/index.js
@@ -7,10 +7,11 @@ program
   .version(pkg.version)
   .usage('[options] <stats>')
   .option('--token <repository-token>', 'specify the repository token')
+  .option('--config-file <file>', 'specify a custom config file')
 
 program.on('--help', () => {
   console.log(`
-  Example:
+  Examples:
     webpack --json | bundle-analyzer --token "your-repository-token"
     cat webpack-stats.json | bundle-analyzer --token "your-repository-token"
 `)
@@ -35,7 +36,11 @@ async function readStdin() {
 async function run() {
   const rawStats = await readStdin()
   const stats = JSON.parse(rawStats)
-  await uploadStats({ webpackStats: stats, token: program.token })
+  await uploadStats({
+    webpackStats: stats,
+    token: program.token,
+    configFile: program.configFile,
+  })
 }
 
 run().catch(error => {
diff --git a/packages/core/README.md b/packages/core/README.md
index 6595535..2311897 100644
--- a/packages/core/README.md
+++ b/packages/core/README.md
@@ -34,6 +34,14 @@ You can specify the token using options or environment variable `BUNDLE_ANALYZER
 
 Custom filesystem.
 
+### context
+
+Search the config file from this repository.
+
+### configFile
+
+Specify a custom config file.
+
 ## Complete documentation
 
 👉 [See full documentation](https://docs.bundle-analyzer.com/)
diff --git a/packages/core/package.json b/packages/core/package.json
index ceb0731..e0dbdf3 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -24,6 +24,7 @@
   "dependencies": {
     "axios": "^0.19.0",
     "brotli-size": "^4.0.0",
+    "cosmiconfig": "^5.2.1",
     "gzip-size": "^5.1.1",
     "omit-deep": "^0.3.0"
   }
diff --git a/packages/core/src/config.js b/packages/core/src/config.js
index 614e912..ca9aec8 100644
--- a/packages/core/src/config.js
+++ b/packages/core/src/config.js
@@ -1,3 +1,25 @@
+import cosmiconfig from 'cosmiconfig'
+
+const explorer = cosmiconfig('bundle-analyzer', {
+  sync: true,
+  cache: true,
+  rcExtensions: true,
+})
+
+export async function resolveConfig(searchFrom, configFile) {
+  if (configFile == null) {
+    const result = await explorer.search(searchFrom)
+    return result ? result.config : null
+  }
+  const result = await explorer.load(configFile)
+  return result ? result.config : null
+}
+
+export async function resolveConfigFile(filePath) {
+  const result = await explorer.search(filePath)
+  return result ? result.filepath : null
+}
+
 export function getToken(configToken) {
   const token = configToken || process.env.BUNDLE_ANALYZER_TOKEN
   if (!token) {
diff --git a/packages/core/src/index.js b/packages/core/src/index.js
index 69495f0..1927569 100644
--- a/packages/core/src/index.js
+++ b/packages/core/src/index.js
@@ -7,7 +7,7 @@ import gzipSize from 'gzip-size'
 import brotliSize from 'brotli-size'
 import omitDeep from 'omit-deep'
 import { detectProvider } from './provider'
-import { getToken, getApiUrl } from './config'
+import { resolveConfig, getToken, getApiUrl } from './config'
 
 const gzip = promisify(zlib.gzip)
 
@@ -39,6 +39,8 @@ function getErrorMessage(error) {
 }
 
 export async function uploadStats({
+  context = process.cwd(),
+  configFile,
   webpackStats,
   token: optionToken,
   fileSystem,
@@ -48,6 +50,7 @@ export async function uploadStats({
     const apiUrl = getApiUrl()
     const metadata = detectProvider()
     const stats = omitDeep(webpackStats, 'source')
+    const config = await resolveConfig(context, configFile)
     const assets = await sizeAssets(stats, { fileSystem })
 
     const { data: bundle } = await axios.post(`${apiUrl}/bundles`, {
@@ -79,6 +82,7 @@ export async function uploadStats({
       branch: metadata.branch,
       commit: metadata.commit,
       providerMetadata: metadata,
+      config,
     })
   } catch (error) {
     throw new Error(getErrorMessage(error))
diff --git a/packages/core/src/index.test.js b/packages/core/src/index.test.js
index f2a421a..14a2190 100644
--- a/packages/core/src/index.test.js
+++ b/packages/core/src/index.test.js
@@ -89,6 +89,7 @@ describe('#uploadStats', () => {
           build_url: 'deploy-url',
           pr: 'review-id',
         },
+        config: null,
       })
       .reply(201)
 
diff --git a/packages/webpack-plugin/README.md b/packages/webpack-plugin/README.md
index 487a46a..14e78a9 100644
--- a/packages/webpack-plugin/README.md
+++ b/packages/webpack-plugin/README.md
@@ -21,7 +21,7 @@ module.exports = {
     path: __dirname + '/dist',
     filename: 'index_bundle.js',
   },
-  plugins: [new BundleAnalyzerPlugin()],
+  plugins: [new BundleAnalyzerPlugin({ token: 'Your repository token' })],
 }
 ```
 
@@ -31,18 +31,9 @@ module.exports = {
 
 You can specify the token using options or environment variable `BUNDLE_ANALYZER_TOKEN`.
 
-```js
-const BundleAnalyzerPlugin = require('@bundle-analyzer/webpack-plugin')
+### configFile
 
-module.exports = {
-  entry: 'index.js',
-  output: {
-    path: __dirname + '/dist',
-    filename: 'index_bundle.js',
-  },
-  plugins: [new BundleAnalyzerPlugin({ token: 'Your repository token' })],
-}
-```
+You can specify a custom configuration file.
 
 ## Complete documentation
 
diff --git a/packages/webpack-plugin/src/index.js b/packages/webpack-plugin/src/index.js
index 42f3aec..199f824 100644
--- a/packages/webpack-plugin/src/index.js
+++ b/packages/webpack-plugin/src/index.js
@@ -1,8 +1,9 @@
 import { uploadStats } from '@bundle-analyzer/core'
 
 class BundleAnalyzer {
-  constructor({ token } = {}) {
+  constructor({ token, configFile } = {}) {
     this.token = token
+    this.configFile = configFile
   }
 
   apply(compiler) {
@@ -10,7 +11,7 @@ class BundleAnalyzer {
       compiler.options.mode === 'production' || !compiler.options.mode
     if (!isProductionLikeMode) return
 
-    const { token } = this
+    const { token, configFile } = this
 
     compiler.hooks.afterEmit.tapAsync(
       '@bundle-analyzer/webpack-plugin',
@@ -23,6 +24,7 @@ class BundleAnalyzer {
         uploadStats({
           webpackStats: stats,
           token,
+          configFile,
           fileSystem: compiler.outputFileSystem,
         })
           .then(() => callback())
diff --git a/yarn.lock b/yarn.lock
index 04343bf..2ed8c98 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3144,7 +3144,7 @@ core-util-is@1.0.2, core-util-is@~1.0.0:
   resolved "https://registry.yarnpkg.com/core-util-is/-/core-util-is-1.0.2.tgz#b5fd54220aa2bc5ab57aab7140c940754503c1a7"
   integrity sha1-tf1UIgqivFq1eqtxQMlAdUUDwac=
 
-cosmiconfig@^5.1.0:
+cosmiconfig@^5.1.0, cosmiconfig@^5.2.1:
   version "5.2.1"
   resolved "https://registry.yarnpkg.com/cosmiconfig/-/cosmiconfig-5.2.1.tgz#040f726809c591e77a17c0a3626ca45b4f168b1a"
   integrity sha512-H65gsXo1SKjf8zmrJ67eJk8aIRKV5ff2D4uKZIBZShbhGSpEmsQOPW/SKMKYhSTrqR7ufy6RP69rPogdaPh/kA==