diff --git a/src/commands/fetch-build-index.ts b/src/commands/fetch-build-index.ts
new file mode 100644
index 0000000..887a6e3
--- /dev/null
+++ b/src/commands/fetch-build-index.ts
@@ -0,0 +1,33 @@
+import { Command, flags } from '@oclif/command'
+import { YAMLMap } from 'yaml/types'
+
+import { DEVICE_CONFIG_FLAGS, loadDeviceConfigs } from '../config/device'
+import { fetchBetaBuildIndex, fetchBuildIndex } from '../images/build-index'
+import { yamlStringifyNoFold } from '../util/yaml'
+
+export default class FetchBuildIndex extends Command {
+  description = 'fetch main or beta build index and print it out as YAML'
+
+  static flags = {
+    ...DEVICE_CONFIG_FLAGS,
+    beta: flags.string({
+      char: 'b',
+      description: 'Fetch index of beta builds for the specified major OS version (e.g. -b 14)',
+    }),
+  }
+
+  async run() {
+    let { flags } = this.parse(FetchBuildIndex)
+    let devices = await loadDeviceConfigs(flags.devices)
+
+    let index: YAMLMap
+    if (flags.beta === undefined) {
+      index = await fetchBuildIndex(devices)
+    } else {
+      index = await fetchBetaBuildIndex(devices, flags.beta)
+    }
+
+    let yaml = yamlStringifyNoFold(index)
+    this.log(yaml)
+  }
+}
diff --git a/src/util/yaml.ts b/src/util/yaml.ts
new file mode 100644
index 0000000..fce2012
--- /dev/null
+++ b/src/util/yaml.ts
@@ -0,0 +1,11 @@
+import YAML, { Options } from 'yaml'
+
+export function yamlStringifyNoFold(value: any, options?: Options) {
+  let orig = YAML.scalarOptions.str.fold.lineWidth
+  YAML.scalarOptions.str.fold.lineWidth = 0
+  try {
+    return YAML.stringify(value, options)
+  } finally {
+    YAML.scalarOptions.str.fold.lineWidth = orig
+  }
+}