diff --git a/README.md b/README.md
index d32e7647..ae670dea 100644
--- a/README.md
+++ b/README.md
@@ -55,6 +55,24 @@ The CLI supports the following options:
 - `--entrypoint <file>`: Confirm the specified file and its transitive dependencies can be resolved using the generated import map. Auto-enabled when importmap is written into an HTML file. Can be specified multiple times.
 - `--dev`: Include devDependencies from `package.json`. Also favor `"development"` in [package exports](https://nodejs.org/docs/latest-v16.x/api/packages.html#packages_conditions_definitions)</a><sup>↗</sup>.
 - `--keep-unused`: Keep all mappings, even if they are not currently used by entry file or its transitive dependencies.
+- `--config <file>`: Read additional settings from the given JSON configuration file.
+
+#### Configuration file
+
+A configuration file in JSON format can be specified with the `--config` CLI option. The following example shows such a JSON file with all supported properties set to their default values:
+
+```json
+{
+  "dir": ".",
+  "dev": false,
+  "keepUnused": false,
+  "entryPoints": [],
+  "manualImportmap": {},
+  "packagesManualOverrides": {}
+}
+```
+
+All properties are optional and CLI options like `--dev`, `--entrypoint` and `--keep-unused` will override the values read from the config. The objects `manualImportmap` and `packagesManualOverrides` have the same format as the corresponding objects in the API.
 
 ### API
 
diff --git a/package.json b/package.json
index 386fed94..da605589 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@jsenv/importmap-node-module",
-  "version": "7.2.2",
+  "version": "7.3.0",
   "description": "Generate importmap for node_modules",
   "license": "MIT",
   "repository": {
diff --git a/src/cli.mjs b/src/cli.mjs
index 5f2189be..1ace50b9 100755
--- a/src/cli.mjs
+++ b/src/cli.mjs
@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 
+import { readFile } from "node:fs/promises";
 import { pathToFileURL } from "node:url";
 import { parseArgs } from "node:util";
 import { writeImportmaps } from "./main.js";
@@ -21,10 +22,12 @@ const options = {
   "keep-unused": {
     type: "boolean",
   },
+  "config": {
+    type: "string",
+  },
 };
 const { values, positionals } = parseArgs({ options, allowPositionals: true });
 const outfile = positionals[0];
-values.entrypoint ??= [];
 
 if (values.help || positionals.length === 0) {
   usage();
@@ -46,21 +49,26 @@ if (
   process.exit(1);
 }
 
+const config = values.config ? JSON.parse(await readFile(values.config, "utf-8")) : {};
+const dev = values.dev ?? config.dev;
+
 const currentDirectoryUrl = pathToFileURL(`${process.cwd()}/`);
 await writeImportmaps({
-  directoryUrl: new URL(values.dir || ".", currentDirectoryUrl),
+  directoryUrl: new URL(values.dir ?? config.dir ?? ".", currentDirectoryUrl),
   importmaps: {
     [outfile]: {
       nodeMappings: {
-        devDependencies: values.dev,
-        packageUserConditions: values.dev ? ["development"] : [],
+        devDependencies: dev,
+        packageUserConditions: dev ? ["development"] : [],
       },
       importResolution: {
-        entryPoints: values.entryPoints,
+        entryPoints: values.entrypoint ?? config.entryPoints ?? [],
       },
-      keepUnusedMappings: values["keep-unused"],
+      keepUnusedMappings: values["keep-unused"] ?? config.keepUnused,
+      manualImportmap: config.manualImportmap,
     },
   },
+  packagesManualOverrides: config.packagesManualOverrides,
 });
 
 function usage() {
@@ -76,6 +84,7 @@ Options:
   --entrypoint file.js Confirm the specified file and its transitive dependencies can be resolved using the generated import map. Can be specified multiple times.
   --dev                Include devDependencies from package.json and pick "developement" in package conditions.
   --keep-unused        Remove mappings not used by any entrypoint or their transitive dependencies. Requires --entrypoint.
+  --config config.json Read additional settings from the given JSON configuration file.
 
 For more advanced options, see the API.`);
 }
diff --git a/tests/cli/cli.test.mjs b/tests/cli/basic/cli_basic.test.mjs
similarity index 91%
rename from tests/cli/cli.test.mjs
rename to tests/cli/basic/cli_basic.test.mjs
index 866224c9..e911da46 100644
--- a/tests/cli/cli.test.mjs
+++ b/tests/cli/basic/cli_basic.test.mjs
@@ -9,7 +9,7 @@ replaceFileStructureSync({
   from: import.meta.resolve("./fixtures/"),
   to: import.meta.resolve("./git_ignored/"),
 });
-execSync("node ../../../src/cli.mjs ./index.html", {
+execSync("node ../../../../src/cli.mjs ./index.html", {
   cwd: new URL(import.meta.resolve("./git_ignored/")),
 });
 copyFileSync({
diff --git a/tests/cli/fixtures/index.html b/tests/cli/basic/fixtures/index.html
similarity index 100%
rename from tests/cli/fixtures/index.html
rename to tests/cli/basic/fixtures/index.html
diff --git a/tests/cli/fixtures/main.js b/tests/cli/basic/fixtures/main.js
similarity index 100%
rename from tests/cli/fixtures/main.js
rename to tests/cli/basic/fixtures/main.js
diff --git a/tests/cli/fixtures/node_modules/foo/foo.js b/tests/cli/basic/fixtures/node_modules/foo/foo.js
similarity index 100%
rename from tests/cli/fixtures/node_modules/foo/foo.js
rename to tests/cli/basic/fixtures/node_modules/foo/foo.js
diff --git a/tests/cli/fixtures/node_modules/foo/package.json b/tests/cli/basic/fixtures/node_modules/foo/package.json
similarity index 100%
rename from tests/cli/fixtures/node_modules/foo/package.json
rename to tests/cli/basic/fixtures/node_modules/foo/package.json
diff --git a/tests/cli/fixtures/package.json b/tests/cli/basic/fixtures/package.json
similarity index 100%
rename from tests/cli/fixtures/package.json
rename to tests/cli/basic/fixtures/package.json
diff --git a/tests/cli/snapshots/index.html b/tests/cli/basic/snapshots/index.html
similarity index 100%
rename from tests/cli/snapshots/index.html
rename to tests/cli/basic/snapshots/index.html
diff --git a/tests/cli/config_file/cli_config_file.test.mjs b/tests/cli/config_file/cli_config_file.test.mjs
new file mode 100644
index 00000000..ae223a81
--- /dev/null
+++ b/tests/cli/config_file/cli_config_file.test.mjs
@@ -0,0 +1,35 @@
+import { assert } from "@jsenv/assert";
+import { startBuildServer } from "@jsenv/core";
+import { copyFileSync, replaceFileStructureSync } from "@jsenv/filesystem";
+import { takeFileSnapshot } from "@jsenv/snapshot";
+import { execSync } from "node:child_process";
+import { executeHtml } from "../../execute_html.js";
+
+const indexHtmlFileSnapshot = takeFileSnapshot(
+  import.meta.resolve("./snapshots/index.html"),
+);
+replaceFileStructureSync({
+  from: import.meta.resolve("./fixtures/"),
+  to: import.meta.resolve("./git_ignored/"),
+});
+execSync(
+  "node ../../../../src/cli.mjs ./index.html --config=importmap.config.json",
+  {
+    cwd: new URL(import.meta.resolve("./git_ignored/")),
+  },
+);
+copyFileSync({
+  from: import.meta.resolve("./git_ignored/index.html"),
+  to: import.meta.resolve("./snapshots/index.html"),
+});
+indexHtmlFileSnapshot.compare();
+
+const buildServer = await startBuildServer({
+  buildDirectoryUrl: import.meta.resolve("./git_ignored/"),
+  keepProcessAlive: false,
+  port: 0,
+  logLevel: "warn",
+});
+const actual = await executeHtml(`${buildServer.origin}/index.html`);
+const expect = "axios";
+assert({ actual, expect });
diff --git a/tests/cli/config_file/fixtures/importmap.config.json b/tests/cli/config_file/fixtures/importmap.config.json
new file mode 100644
index 00000000..c0b3881d
--- /dev/null
+++ b/tests/cli/config_file/fixtures/importmap.config.json
@@ -0,0 +1,7 @@
+{
+  "packagesManualOverrides": {
+    "axios": {
+      "exports": "./dist/esm/axios.js"
+    }
+  }
+}
diff --git a/tests/cli/config_file/fixtures/index.html b/tests/cli/config_file/fixtures/index.html
new file mode 100644
index 00000000..071ec4a0
--- /dev/null
+++ b/tests/cli/config_file/fixtures/index.html
@@ -0,0 +1,17 @@
+<!doctype html>
+<html>
+  <head>
+    <title>Title</title>
+    <meta charset="utf-8" />
+    <link rel="icon" href="data:," />
+  </head>
+
+  <body>
+    <script>
+      window.resultPromise = new Promise((resolve) => {
+        window.resolveResultPromise = resolve;
+      });
+    </script>
+    <script type="module" src="./main.js"></script>
+  </body>
+</html>
diff --git a/tests/cli/config_file/fixtures/main.js b/tests/cli/config_file/fixtures/main.js
new file mode 100644
index 00000000..6091e77c
--- /dev/null
+++ b/tests/cli/config_file/fixtures/main.js
@@ -0,0 +1,6 @@
+/* globals window */
+
+// eslint-disable-next-line import-x/no-unresolved
+import { axios } from "axios";
+
+window.resolveResultPromise(axios);
diff --git a/tests/cli/config_file/fixtures/node_modules/axios/dist/esm/axios.js b/tests/cli/config_file/fixtures/node_modules/axios/dist/esm/axios.js
new file mode 100644
index 00000000..dc03e499
--- /dev/null
+++ b/tests/cli/config_file/fixtures/node_modules/axios/dist/esm/axios.js
@@ -0,0 +1 @@
+export const axios = 'axios';
\ No newline at end of file
diff --git a/tests/cli/config_file/fixtures/node_modules/axios/package.json b/tests/cli/config_file/fixtures/node_modules/axios/package.json
new file mode 100644
index 00000000..3a8534bc
--- /dev/null
+++ b/tests/cli/config_file/fixtures/node_modules/axios/package.json
@@ -0,0 +1,5 @@
+{
+    "name": "axios",
+    "main": "./foo.js",
+    "private": true
+}
\ No newline at end of file
diff --git a/tests/cli/config_file/fixtures/package.json b/tests/cli/config_file/fixtures/package.json
new file mode 100644
index 00000000..d1e33047
--- /dev/null
+++ b/tests/cli/config_file/fixtures/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "root",
+  "private": true,
+  "dependencies": {
+    "axios": "*"
+  }
+}
diff --git a/tests/cli/config_file/snapshots/index.html b/tests/cli/config_file/snapshots/index.html
new file mode 100644
index 00000000..48253f2a
--- /dev/null
+++ b/tests/cli/config_file/snapshots/index.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Title</title>
+    <meta charset="utf-8">
+    <link rel="icon" href="data:,">
+    <script type="importmap" jsenv-injected-by="@jsenv/importmap-node-module">
+      {
+        "imports": {
+          "axios": "./node_modules/axios/dist/esm/axios.js"
+        },
+        "scopes": {}
+      }
+    </script>
+  </head>
+
+  <body>
+    <script>
+      window.resultPromise = new Promise((resolve) => {
+        window.resolveResultPromise = resolve;
+      });
+    </script>
+    <script type="module" src="./main.js"></script>
+  </body>
+</html>
\ No newline at end of file