diff --git a/features/add-oembed-provider.feature b/features/add-oembed-provider.feature
new file mode 100644
index 0000000..4ccfdde
--- /dev/null
+++ b/features/add-oembed-provider.feature
@@ -0,0 +1,321 @@
+Feature: Register and use custom oEmbed providers
+
+  Background:
+    Given a WP install
+    And a filter-providers.php file:
+      """
+      <?php
+      WP_CLI::add_wp_hook( 'init', function () {
+        wp_oembed_add_provider( 'http://example.com/*', 'http://example.com/api/oembed.{format}' );
+      });
+      """
+
+  Scenario: List oEmbed providers after registration
+    When I run `wp embed provider list --require=filter-providers.php`
+    And save STDOUT as {DEFAULT_STDOUT}
+    Then STDOUT should contain:
+      """
+      format
+      """
+    And STDOUT should contain:
+      """
+      endpoint
+      """
+    And STDOUT should not contain:
+      """
+      regex
+      """
+    And STDOUT should contain:
+      """
+      http://example.com/*
+      """
+    And STDOUT should contain:
+      """
+      http://example.com/api/oembed.{format}
+      """
+    And STDOUT should contain:
+      """
+      youtube\.com/watch.*
+      """
+    And STDOUT should contain:
+      """
+      //www.youtube.com/oembed
+      """
+    And STDOUT should contain:
+      """
+      flickr\.com/
+      """
+    And STDOUT should contain:
+      """
+      flickr.com
+      """
+    And STDOUT should contain:
+      """
+      twitter\.com/
+      """
+    And STDOUT should contain:
+      """
+      twitter.com
+      """
+    And STDOUT should contain:
+      """
+      \.spotify\.com/
+      """
+    And STDOUT should contain:
+      """
+      spotify.com
+      """
+
+    When I run `wp embed provider list --fields=format,endpoint --require=filter-providers.php`
+    Then STDOUT should be:
+      """
+      {DEFAULT_STDOUT}
+      """
+
+    When I run `wp embed provider list --force-regex --require=filter-providers.php`
+    Then STDOUT should contain:
+      """
+      #https?\://example\.com/(.+)#i
+      """
+    And STDOUT should contain:
+      """
+      http://example.com/api/oembed.{format}
+      """
+    And STDOUT should not contain:
+      """
+      http://example.com/*
+      """
+    And STDOUT should match /^#http/m
+
+    When I run `wp embed provider list --fields=format`
+    Then STDOUT should contain:
+      """
+      format
+      """
+    And STDOUT should not contain:
+      """
+      endpoint
+      """
+    And STDOUT should contain:
+      """
+      youtube\.com/watch.*
+      """
+    And STDOUT should not contain:
+      """
+      youtube.com
+      """
+
+    When I run `wp embed provider list --field=format`
+    Then STDOUT should not contain:
+      """
+      format
+      """
+    And STDOUT should not contain:
+      """
+      endpoint
+      """
+    And STDOUT should contain:
+      """
+      youtube\.com/watch.*
+      """
+    And STDOUT should not contain:
+      """
+      youtube.com
+      """
+
+    When I run `wp embed provider list --field=regex`
+    Then STDOUT should match /^(?:(?:1|0)\n)+$/
+
+  @require-wp-4.0
+  Scenario: Match an oEmbed provider
+    # Provider not requiring discovery
+    When I run `wp embed provider match https://www.youtube.com/watch?v=dQw4w9WgXcQ`
+    Then STDOUT should contain:
+      """
+      //www.youtube.com/oembed
+      """
+
+    # Provider requiring discovery
+    # Old versions of WP_oEmbed can trigger PHP "Only variables should be passed by reference" notices on discover so use "try" to cater for these.
+    When I try `wp embed provider match https://audio.com/audio-com/collections/ambient-focus`
+    And save STDOUT as {DEFAULT_STDOUT}
+    Then the return code should be 0
+    And STDERR should not contain:
+      """
+      Error:
+      """
+    And STDOUT should contain:
+      """
+      audio.com/
+      """
+    And STDOUT should contain:
+      """
+      json
+      """
+    And STDOUT should not contain:
+      """
+      xml
+      """
+
+    # Old versions of WP_oEmbed can trigger PHP "Only variables should be passed by reference" notices on discover so use "try" to cater for these.
+    When I try `wp embed provider match https://audio.com/audio-com/collections/ambient-focus --link-type=json`
+    Then the return code should be 0
+    And STDERR should not contain:
+      """
+      Error:
+      """
+    And STDOUT should be:
+      """
+      {DEFAULT_STDOUT}
+      """
+
+    # Old versions of WP_oEmbed can trigger PHP "Only variables should be passed by reference" notices on discover so use "try" to cater for these.
+    When I try `wp embed provider match https://audio.com/audio-com/collections/ambient-focus --link-type=xml`
+    Then the return code should be 0
+    And STDERR should not contain:
+      """
+      Error:
+      """
+    And STDOUT should not contain:
+      """
+      {DEFAULT_STDOUT}
+      """
+    And STDOUT should contain:
+      """
+      audio.com/
+      """
+    And STDOUT should contain:
+      """
+      xml
+      """
+    And STDOUT should not contain:
+      """
+      json
+      """
+
+  # Depends on `oembed_remote_get_args` filter introduced in WP 4.0 https://core.trac.wordpress.org/ticket/23442
+  @require-wp-4.0
+  Scenario: Discover a provider with limited response size
+    When I run `wp embed provider match https://audio.com/audio-com/collections/ambient-focus`
+    Then save STDOUT as {DEFAULT_STDOUT}
+
+    # Response limit too small
+    When I try `wp embed provider match https://audio.com/audio-com/collections/ambient-focus --limit-response-size=10`
+    Then the return code should be 1
+    And STDERR should be:
+      """
+      Error: No oEmbed provider found for given URL.
+      """
+
+    # Response limit big enough
+    When I run `wp embed provider match https://audio.com/audio-com/collections/ambient-focus --limit-response-size=50000`
+    Then STDOUT should be:
+      """
+      {DEFAULT_STDOUT}
+      """
+
+  Scenario: Fail to match an oEmbed provider
+    When I try `wp embed provider match https://www.example.com/watch?v=dQw4w9WgXcQ --no-discover`
+    Then the return code should be 1
+    And STDERR should be:
+      """
+      Error: No oEmbed provider found for given URL. Maybe try discovery?
+      """
+    And STDOUT should be empty
+
+    When I try `wp embed provider match https://www.example.com/watch?v=dQw4w9WgXcQ`
+    Then the return code should be 1
+    # Old versions of WP_oEmbed can trigger PHP "Only variables should be passed by reference" notices on discover so use "contain" to ignore these.
+    And STDERR should contain:
+      """
+      Error: No oEmbed provider found for given URL.
+      """
+    And STDOUT should be empty
+
+    When I try `wp embed provider match https://www.example.com/watch?v=dQw4w9WgXcQ --discover`
+    Then the return code should be 1
+    # Old versions of WP_oEmbed can trigger PHP "Only variables should be passed by reference" notices on discover so use "contain" to ignore these.
+    And STDERR should contain:
+      """
+      Error: No oEmbed provider found for given URL.
+      """
+    And STDOUT should be empty
+
+  @require-wp-4.0
+  Scenario: Only match an oEmbed provider if discover
+    When I try `wp embed provider match https://audio.com/audio-com/collections/ambient-focus --no-discover`
+    Then the return code should be 1
+    And STDERR should be:
+      """
+      Error: No oEmbed provider found for given URL. Maybe try discovery?
+      """
+    And STDOUT should be empty
+
+    # Old versions of WP_oEmbed can trigger PHP "Only variables should be passed by reference" notices on discover so use "try" to cater for these.
+    When I try `wp embed provider match https://audio.com/audio-com/collections/ambient-focus`
+    Then the return code should be 0
+    And STDERR should not contain:
+      """
+      Error:
+      """
+    And STDOUT should contain:
+      """
+      audio.com/
+      """
+    And STDOUT should contain:
+      """
+      collection
+      """
+
+    # Old versions of WP_oEmbed can trigger PHP "Only variables should be passed by reference" notices on discover so use "try" to cater for these.
+    When I try `wp embed provider match https://audio.com/audio-com/collections/ambient-focus --discover`
+    Then the return code should be 0
+    And STDERR should not contain:
+      """
+      Error:
+      """
+    And STDOUT should contain:
+      """
+      audio.com/
+      """
+
+  Scenario: Match custom oEmbed provider after registration
+    When I run `wp embed provider match http://example.com/foo --require=filter-providers.php`
+    Then STDOUT should be:
+      """
+      http://example.com/api/oembed.json
+      """
+
+  Scenario: Incompatible or wrong options
+    When I try `wp embed provider match https://www.example.com/watch?v=dQw4w9WgXcQ --no-discover --limit-response-size=50000`
+    Then the return code should be 1
+    And STDERR should be:
+      """
+      Error: The 'limit-response-size' option can only be used with discovery.
+      """
+    And STDOUT should be empty
+
+    When I try `wp embed provider match https://www.example.com/watch?v=dQw4w9WgXcQ --no-discover --link-type=json`
+    Then the return code should be 1
+    And STDERR should be:
+      """
+      Error: The 'link-type' option can only be used with discovery.
+      """
+    And STDOUT should be empty
+
+    When I try `wp embed provider match https://www.example.com/watch?v=dQw4w9WgXcQ --no-discover --limit-response-size=50000 --link-type=json`
+    Then the return code should be 1
+    And STDERR should be:
+      """
+      Error: The 'limit-response-size' and 'link-type' options can only be used with discovery.
+      """
+    And STDOUT should be empty
+
+    When I try `wp embed provider match https://www.example.com/watch?v=dQw4w9WgXcQ --no-discover --link-type=blah`
+    Then the return code should be 1
+    And STDERR should contain:
+      """
+      Error: Parameter errors:
+       Invalid value specified for 'link-type'
+      """
+    And STDOUT should be empty
diff --git a/src/Provider_Command.php b/src/Provider_Command.php
index 9cc8ff7..2a56151 100644
--- a/src/Provider_Command.php
+++ b/src/Provider_Command.php
@@ -86,7 +86,8 @@ class Provider_Command extends WP_CLI_Command {
 	 */
 	public function list_providers( $args, $assoc_args ) {
 
-		$oembed = new \WP_oEmbed();
+		// We use _wp_oembed_get_object to get the singleton, which contains all the registered providers.
+		$oembed = _wp_oembed_get_object();
 
 		$force_regex = Utils\get_flag_value( $assoc_args, 'force-regex' );
 
@@ -146,7 +147,7 @@ public function list_providers( $args, $assoc_args ) {
 	 * @param array{discover?: bool, 'limit-response-size'?: string, 'link-type'?: 'json'|'xml', } $assoc_args Associative arguments.
 	 */
 	public function match_provider( $args, $assoc_args ) {
-		$oembed = new \WP_oEmbed();
+		$oembed = _wp_oembed_get_object();
 
 		$url                 = $args[0];
 		$discover            = Utils\get_flag_value( $assoc_args, 'discover', true );