diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
new file mode 100644
index 0000000..f5726aa
--- /dev/null
+++ b/.github/workflows/deploy.yml
@@ -0,0 +1,59 @@
+name: Deploy
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby-version: ['2.7', '3.0', '3.1', '3.2']
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby-version }}
+        bundler-cache: true
+    - name: Install dependencies
+      run: bundle install
+    - name: Run RSpec
+      run: bundle exec rspec
+
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: '3.2'
+        bundler-cache: true
+    - name: Install dependencies
+      run: bundle install
+    - name: Run RuboCop
+      run: bundle exec rubocop
+
+  deploy:
+    needs: [test, lint]
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: '3.2'
+        bundler-cache: true
+    - name: Install dependencies
+      run: bundle install
+    - name: Build gem
+      run: gem build *.gemspec
+    - name: Push to RubyGems
+      run: |
+        mkdir -p $HOME/.gem
+        echo ":rubygems_api_key: ${{ secrets.RUBY_GEMS_TOKEN }}" > $HOME/.gem/credentials
+        chmod 0600 $HOME/.gem/credentials
+        gem push *.gem
diff --git a/.gitignore b/.gitignore
index b8bc553..595af0f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,5 @@ Gemfile.lock
 .DS_Store
 pkg
 vendor/bundle
+.yardoc
+doc
diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md
new file mode 100644
index 0000000..a74005a
--- /dev/null
+++ b/CODE_OF_CONDUCT.md
@@ -0,0 +1,66 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, religion, or sexual identity
+and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community include:
+
+*   Demonstrating empathy and kindness toward other people
+*   Being respectful of differing opinions, viewpoints, and experiences
+*   Giving and gracefully accepting constructive feedback
+*   Accepting responsibility and apologizing to those affected by our mistakes,
+    and learning from the experience
+*   Focusing on what is best not just for us as individuals, but for the
+    overall community
+
+Examples of unacceptable behavior include:
+
+*   The use of sexualized language or imagery, and sexual attention or
+    advances of any kind
+*   Trolling, insulting or derogatory comments, and personal or political attacks
+*   Public or private harassment
+*   Publishing others' private information, such as a physical or email
+    address, without their explicit permission
+*   Other conduct which could reasonably be considered inappropriate in a
+    professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official e-mail address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 2.0, available at
+[https://www.contributor-covenant.org/version/2/0/code_of_conduct.html][v2.0].
+
+[homepage]: https://www.contributor-covenant.org
+[v2.0]: https://www.contributor-covenant.org/version/2/0/code_of_conduct.html
diff --git a/README.md b/README.md
index 6200c95..36a219e 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,15 @@
 
 A modern, robust, and fully-featured Ruby client for the Zadarma API. This gem has been updated to support the latest Zadarma API, providing a clean and intuitive interface for all available endpoints.
 
-## Installation
+## Getting Started
+
+### Prerequisites
+
+- Ruby 2.7 or later
+- A Zadarma account
+- Your Zadarma API key and secret
+
+### Installation
 
 Add this line to your application's Gemfile:
 
@@ -18,7 +26,7 @@ Or install it yourself as:
 
     $ gem install zadarma
 
-## Usage
+## Configuration
 
 First, configure the client with your API key and secret. You can find these in your Zadarma personal account.
 
@@ -28,6 +36,8 @@ require 'zadarma'
 client = Zadarma::Client.new(api_key: 'YOUR_API_KEY', api_secret: 'YOUR_API_SECRET')
 ```
 
+## Usage
+
 Now you can call any of the available API methods:
 
 ### Get Your Balance
@@ -92,7 +102,7 @@ This client is organized into resources, mirroring the Zadarma API structure.
     *   `statistics(start:, end_date:, sip: nil, cost_only: nil, type: nil, skip: nil, limit: nil)`: Get overall call statistics.
     *   `pbx_statistics(start:, end_date:, version: nil, skip: nil, limit: nil, call_type: nil)`: Get PBX call statistics.
 
-## Development & Testing
+## Development
 
 To work on this gem locally, clone the repository and then run `bundle install` to install the dependencies.
 
@@ -109,3 +119,15 @@ The test suite is configured to use `webmock` to stub out all API requests, so y
 3.  Commit your changes (`git commit -am 'Add some feature'`)
 4.  Push to the branch (`git push origin my-new-feature`)
 5.  Create a new Pull Request
+
+## License
+
+The gem is available as open source under the terms of the [MIT License](https'://opensource.org/licenses/MIT).
+
+## Code of Conduct
+
+Everyone interacting in the Zadarma project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](CODE_OF_CONDUCT.md).
+
+## Version History
+
+*   **2.0.0** - The current version.
diff --git a/lib/zadarma/client.rb b/lib/zadarma/client.rb
index 53b0237..2e4043b 100644
--- a/lib/zadarma/client.rb
+++ b/lib/zadarma/client.rb
@@ -27,140 +27,333 @@ class Client
 
     API_URL = 'https://api.zadarma.com'
 
+    # Initializes a new Client object.
+    #
+    # @param api_key [String] The Zadarma API key.
+    # @param api_secret [String] The Zadarma API secret.
     def initialize(api_key:, api_secret:)
       @api_key = api_key
       @api_secret = api_secret
     end
 
+    # Get the current account balance.
+    #
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_balance
     def balance
       info.balance
     end
 
+    # Get the price for a call to a specific number.
+    #
+    # @param number [String] The destination number.
+    # @param caller_id [String] The caller ID.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_price
     def price(number:, caller_id: nil)
       info.price(number: number, caller_id: caller_id)
     end
 
+    # Get a list of internal PBX numbers.
+    #
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_pbx_internal
     def internal_numbers
       pbx.internal
     end
 
+    # Enable or disable call recording for a PBX extension.
+    #
+    # @param id [String] The PBX extension ID.
+    # @param status [String] The recording status.
+    # @param email [String] The email address to send the recording to.
+    # @param speech_recognition [String] The speech recognition status.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_pbx_record
     def set_call_recording(id:, status:, email: nil, speech_recognition: nil)
       pbx.set_call_recording(id: id, status: status, email: email, speech_recognition: speech_recognition)
     end
 
+    # Request a call recording from the PBX.
+    #
+    # @param call_id [String] The call ID.
+    # @param pbx_call_id [String] The PBX call ID.
+    # @param lifetime [String] The lifetime of the recording.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_pbx_record_request
     def pbx_record_request(call_id: nil, pbx_call_id: nil, lifetime: nil)
       pbx.pbx_record_request(call_id: call_id, pbx_call_id: pbx_call_id, lifetime: lifetime)
     end
 
+    # Get a list of direct numbers.
+    #
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_direct_numbers
     def direct_numbers
       direct_numbers_resource.all
     end
 
+    # Get a list of countries for direct numbers.
+    #
+    # @param language [String] The language of the response.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_direct_number_countries
     def direct_number_countries(language: nil)
       direct_numbers_resource.countries(language: language)
     end
 
+    # Get a list of direct numbers for a specific country.
+    #
+    # @param country [String] The country code.
+    # @param language [String] The language of the response.
+    # @param direction_id [String] The direction ID.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_direct_number_country
     def direct_number_country(country:, language: nil, direction_id: nil)
       direct_numbers_resource.country(country: country, language: language, direction_id: direction_id)
     end
 
+    # Get a list of available direct numbers.
+    #
+    # @param direction_id [String] The direction ID.
+    # @param mask [String] The number mask.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_available_direct_numbers
     def available_direct_numbers(direction_id:, mask: nil)
       direct_numbers_resource.available(direction_id: direction_id, mask: mask)
     end
 
+    # Order a direct number.
+    #
+    # @param params [Hash] The order parameters.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_order_direct_number
     def order_direct_number(params)
       direct_numbers_resource.order(params)
     end
 
+    # Prolong a direct number.
+    #
+    # @param number [String] The direct number.
+    # @param months [String] The number of months to prolong the number for.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_prolong_direct_number
     def prolong_direct_number(number:, months:)
       direct_numbers_resource.prolong(number: number, months: months)
     end
 
+    # Initiate a callback between two numbers.
+    #
+    # @param from [String] The source number.
+    # @param to [String] The destination number.
+    # @param sip [String] The SIP number.
+    # @param predicted [String] The predicted status.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_callback
     def callback(from:, to:, sip: nil, predicted: nil)
       request_resource.callback(from: from, to: to, sip: sip, predicted: predicted)
     end
 
+    # Get a list of SIP numbers.
+    #
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_sips
     def sips
       sip.all
     end
 
+    # Get the status of a SIP number.
+    #
+    # @param sip [String] The SIP number.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_sip_status
     def sip_status(sip:)
       self.sip.status(sip: sip)
     end
 
+    # Create a SIP number.
+    #
+    # @param name [String] The SIP number name.
+    # @param password [String] The SIP number password.
+    # @param callerid [String] The SIP number caller ID.
+    # @param redirect_to_phone [String] The phone number to redirect to.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_create_sip
     def create_sip(name:, password: nil, callerid: nil, redirect_to_phone: nil)
       sip.create(name: name, password: password, callerid: callerid, redirect_to_phone: redirect_to_phone)
     end
 
+    # Set the password for a SIP number.
+    #
+    # @param sip [String] The SIP number.
+    # @param value [String] The new password.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_set_sip_password
     def set_sip_password(sip:, value:)
       self.sip.password(sip: sip, value: value)
     end
 
+    # Set the caller ID for a SIP number.
+    #
+    # @param id [String] The SIP number ID.
+    # @param number [String] The new caller ID.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_set_sip_caller_id
     def set_sip_caller_id(id:, number:)
       sip.set_caller_id(id: id, number: number)
     end
 
+    # Get call forwarding information for a SIP number.
+    #
+    # @param id [String] The SIP number ID.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_redirection
     def redirection(id: nil)
       sip.redirection(id: id)
     end
 
+    # Set call forwarding for a SIP number.
+    #
+    # @param id [String] The SIP number ID.
+    # @param status [String] The forwarding status.
+    # @param type [String] The forwarding type.
+    # @param number [String] The forwarding number.
+    # @param condition [String] The forwarding condition.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_set_redirection
     def set_redirection(id:, status:, type: nil, number: nil, condition: nil)
       sip.set_redirection(id: id, status: status, type: type, number: number, condition: condition)
     end
 
+    # Send an SMS message.
+    #
+    # @param number [String] The destination number.
+    # @param message [String] The message text.
+    # @param sender [String] The sender ID.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_send_sms
     def send_sms(number:, message:, sender: nil)
       sms.send_sms(number: number, message: message, sender: sender)
     end
 
+    # Get overall call statistics.
+    #
+    # @param params [Hash] The statistics parameters.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_statistics
     def statistics(params)
       statistics_resource.statistics(params)
     end
 
+    # Get PBX call statistics.
+    #
+    # @param params [Hash] The statistics parameters.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_pbx_statistics
     def pbx_statistics(params)
       statistics_resource.pbx_statistics(params)
     end
 
+    # Get speech recognition results.
+    #
+    # @param call_id [String] The call ID.
+    # @param lang [String] The language of the speech.
+    # @param return_results [String] Whether to return the results.
+    # @param alternatives [String] Whether to return alternative results.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_get_speech_recognition
     def get_speech_recognition(call_id:, lang: nil, return_results: nil, alternatives: nil)
       speech_recognition_resource.get(call_id: call_id, lang: lang, return_results: return_results,
                                       alternatives: alternatives)
     end
 
+    # Initiate speech recognition.
+    #
+    # @param call_id [String] The call ID.
+    # @param lang [String] The language of the speech.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_initiate_speech_recognition
     def initiate_speech_recognition(call_id:, lang: nil)
       speech_recognition_resource.initiate(call_id: call_id, lang: lang)
     end
 
+    # Get a list of document files.
+    #
+    # @param group_id [String] The group ID.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_document_files
     def document_files(group_id: nil)
       groups_of_documents_resource.files(group_id: group_id)
     end
 
+    # Get a list of document groups.
+    #
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_document_groups
     def document_groups
       groups_of_documents_resource.list
     end
 
+    # Get a document group.
+    #
+    # @param id [String] The group ID.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_get_document_group
     def get_document_group(id:)
       groups_of_documents_resource.get(id: id)
     end
 
+    # Create a document group.
+    #
+    # @param params [Hash] The group parameters.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_create_document_group
     def create_document_group(params:)
       groups_of_documents_resource.create(params: params)
     end
 
+    # Update a document group.
+    #
+    # @param id [String] The group ID.
+    # @param params [Hash] The group parameters.
+    # @return [Hash] The API response.
+    # @see https://zadarma.com/en/support/api/#api_update_document_group
     def update_document_group(id:, params:)
       groups_of_documents_resource.update(id: id, params: params)
     end
 
+    # Make a GET request to the Zadarma API.
+    #
+    # @param path [String] The API endpoint path.
+    # @param params [Hash] The request parameters.
+    # @return [Hash] The API response.
     def get(path, params = {})
       request(:get, path, params)
     end
 
+    # Make a POST request to the Zadarma API.
+    #
+    # @param path [String] The API endpoint path.
+    # @param params [Hash] The request parameters.
+    # @return [Hash] The API response.
     def post(path, params = {})
       request(:post, path, params)
     end
 
+    # Make a PUT request to the Zadarma API.
+    #
+    # @param path [String] The API endpoint path.
+    # @param params [Hash] The request parameters.
+    # @return [Hash] The API response.
     def put(path, params = {})
       request(:put, path, params)
     end
 
+    # Make a DELETE request to the Zadarma API.
+    #
+    # @param path [String] The API endpoint path.
+    # @param params [Hash] The request parameters.
+    # @return [Hash] The API response.
     def delete(path, params = {})
       request(:delete, path, params)
     end
diff --git a/mkdocs/direct_numbers.md b/mkdocs/direct_numbers.md
new file mode 100644
index 0000000..d922384
--- /dev/null
+++ b/mkdocs/direct_numbers.md
@@ -0,0 +1,111 @@
+# Direct Numbers Resource
+
+The Direct Numbers resource allows you to manage virtual numbers.
+
+## `all()`
+
+Get information about the user's virtual numbers.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.direct_numbers
+```
+
+## `countries(language: nil)`
+
+Get a list of countries where numbers can be ordered.
+
+**Parameters:**
+
+*   `language` (String): The language for the country names.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.direct_number_countries(language: 'en')
+```
+
+## `country(country:, language: nil, direction_id: nil)`
+
+Get a list of destinations in a country where a number can be ordered.
+
+**Parameters:**
+
+*   `country` (String): The ISO country code.
+*   `language` (String): The language for the destination names.
+*   `direction_id` (String): The direction ID.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.direct_number_country(country: 'US')
+```
+
+## `available(direction_id:, mask: nil)`
+
+Get a list of available numbers for a given direction.
+
+**Parameters:**
+
+*   `direction_id` (String): The direction ID.
+*   `mask` (String): A mask for searching number matches.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.available_direct_numbers(direction_id: '123')
+```
+
+## `order(params)`
+
+Order a virtual number.
+
+**Parameters:**
+
+*   `params` (Hash): The parameters for ordering a number.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.order_direct_number(direction_id: '123', number_id: '456')
+```
+
+## `prolong(number:, months:)`
+
+Prepay the number for the specified number of months.
+
+**Parameters:**
+
+*   `number` (String): The number to be prolonged.
+*   `months` (Integer): The number of months.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.prolong_direct_number(number: '1234567890', months: 3)
+```
diff --git a/mkdocs/groups_of_documents.md b/mkdocs/groups_of_documents.md
new file mode 100644
index 0000000..6cfb9ed
--- /dev/null
+++ b/mkdocs/groups_of_documents.md
@@ -0,0 +1,90 @@
+# Groups of Documents Resource
+
+The Groups of Documents resource allows you to manage groups of documents.
+
+## `files(group_id: nil)`
+
+Get the list of files/documents in the group of documents.
+
+**Parameters:**
+
+*   `group_id` (String): The group of documents ID.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.document_files(group_id: '123')
+```
+
+## `list()`
+
+Get the list of groups of documents.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.document_groups
+```
+
+## `get(id:)`
+
+Get information on a certain group.
+
+**Parameters:**
+
+*   `id` (String): The group ID.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.get_document_group(id: '123')
+```
+
+## `create(params:)`
+
+Create a new group of documents.
+
+**Parameters:**
+
+*   `params` (Hash): The parameters for creating a new group of documents.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.create_document_group(params: { name: 'My Group' })
+```
+
+## `update(id:, params:)`
+
+Update a group of documents.
+
+**Parameters:**
+
+*   `id` (String): The group ID.
+*   `params` (Hash): The parameters for updating a group of documents.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.update_document_group(id: '123', params: { name: 'My New Group' })
+```
diff --git a/mkdocs/index.md b/mkdocs/index.md
new file mode 100644
index 0000000..cc1ebff
--- /dev/null
+++ b/mkdocs/index.md
@@ -0,0 +1,45 @@
+# Zadarma API Ruby Client Documentation
+
+Welcome to the developer documentation for the Zadarma API Ruby Client. This guide provides detailed information about every aspect of the gem, from installation and configuration to a complete reference of all available API methods.
+
+## Getting Started
+
+### Installation
+
+Add this line to your application's Gemfile:
+
+```ruby
+gem 'zadarma'
+```
+
+And then execute:
+
+    $ bundle
+
+Or install it yourself as:
+
+    $ gem install zadarma
+
+### Configuration
+
+First, configure the client with your API key and secret. You can find these in your Zadarma personal account.
+
+```ruby
+require 'zadarma'
+
+client = Zadarma::Client.new(api_key: 'YOUR_API_KEY', api_secret: 'YOUR_API_SECRET')
+```
+
+## API Resources
+
+This client is organized into resources, mirroring the Zadarma API structure. Click on a resource below for a detailed list of its methods and parameters.
+
+*   [Info](info.md)
+*   [PBX](pbx.md)
+*   [Direct Numbers](direct_numbers.md)
+*   [Request](request.md)
+*   [SIP](sip.md)
+*   [SMS](sms.md)
+*   [Statistics](statistics.md)
+*   [Speech Recognition](speech_recognition.md)
+*   [Groups of Documents](groups_of_documents.md)
diff --git a/mkdocs/info.md b/mkdocs/info.md
new file mode 100644
index 0000000..01f9e6c
--- /dev/null
+++ b/mkdocs/info.md
@@ -0,0 +1,36 @@
+# Info Resource
+
+The Info resource provides access to user information, such as balance and call rates.
+
+## `balance()`
+
+Get the user's balance.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.balance
+```
+
+## `price(number:, caller_id: nil)`
+
+Get the call rate for a given number.
+
+**Parameters:**
+
+*   `number` (String): The phone number.
+*   `caller_id` (String): The CallerID to be used for the call.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.price(number: '1234567890')
+```
diff --git a/mkdocs/pbx.md b/mkdocs/pbx.md
new file mode 100644
index 0000000..450312c
--- /dev/null
+++ b/mkdocs/pbx.md
@@ -0,0 +1,58 @@
+# PBX Resource
+
+The PBX resource allows you to manage your Zadarma PBX.
+
+## `internal()`
+
+Get the list of PBX internal numbers.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.internal_numbers
+```
+
+## `set_call_recording(id:, status:, email: nil, speech_recognition: nil)`
+
+Set the call recording for a PBX extension.
+
+**Parameters:**
+
+*   `id` (String): The PBX extension ID.
+*   `status` (String): The call recording status ('on', 'off', etc.).
+*   `email` (String): The email address to send recordings to.
+*   `speech_recognition` (String): The speech recognition settings.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.set_call_recording(id: '123', status: 'on')
+```
+
+## `pbx_record_request(call_id: nil, pbx_call_id: nil, lifetime: nil)`
+
+Request a call recording file.
+
+**Parameters:**
+
+*   `call_id` (String): The unique call ID.
+*   `pbx_call_id` (String): The permanent ID of the external call to the PBX.
+*   `lifetime` (Integer): The link's lifetime in seconds.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.pbx_record_request(call_id: '12345')
+```
diff --git a/mkdocs/request.md b/mkdocs/request.md
new file mode 100644
index 0000000..44cf9f5
--- /dev/null
+++ b/mkdocs/request.md
@@ -0,0 +1,24 @@
+# Request Resource
+
+The Request resource allows you to initiate callbacks.
+
+## `callback(from:, to:, sip: nil, predicted: nil)`
+
+Request a callback.
+
+**Parameters:**
+
+*   `from` (String): Your phone/SIP number, the PBX extension or the PBX scenario.
+*   `to` (String): The phone or SIP number that is being called.
+*   `sip` (String): The SIP user's number or the PBX extension.
+*   `predicted` (String): If specified, the request is predicted.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.callback(from: '1234567890', to: '0987654321')
+```
diff --git a/mkdocs/sip.md b/mkdocs/sip.md
new file mode 100644
index 0000000..5366c7a
--- /dev/null
+++ b/mkdocs/sip.md
@@ -0,0 +1,134 @@
+# SIP Resource
+
+The SIP resource allows you to manage your SIP numbers.
+
+## `all()`
+
+Get the list of user's SIP-numbers.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.sips
+```
+
+## `set_caller_id(id:, number:)`
+
+Set the CallerID for a SIP number.
+
+**Parameters:**
+
+*   `id` (String): The SIP ID.
+*   `number` (String): The new CallerID.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.set_sip_caller_id(id: '123', number: '1234567890')
+```
+
+## `redirection(id: nil)`
+
+Get call forwarding information for a SIP number.
+
+**Parameters:**
+
+*   `id` (String): The SIP ID.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.redirection(id: '123')
+```
+
+## `set_redirection(id:, status:, type: nil, number: nil, condition: nil)`
+
+Set call forwarding for a SIP number.
+
+**Parameters:**
+
+*   `id` (String): The SIP ID.
+*   `status` (String): The call forwarding status ('on' or 'off').
+*   `type` (String): The call forwarding type ('phone', 'voicemail', etc.).
+*   `number` (String): The destination number for call forwarding.
+*   `condition` (String): The call forwarding condition ('always', 'noanswer', etc.).
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.set_redirection(id: '123', status: 'on', type: 'phone', number: '1234567890')
+```
+
+## `status(sip:)`
+
+Get the online status of a SIP number.
+
+**Parameters:**
+
+*   `sip` (String): The SIP number.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.sip_status(sip: '123')
+```
+
+## `create(name:, password: nil, callerid: nil, redirect_to_phone: nil)`
+
+Create a new SIP number.
+
+**Parameters:**
+
+*   `name` (String): The displayed name for the new SIP number.
+*   `password` (String): The password for the new SIP number.
+*   `callerid` (String): The CallerID for the new SIP number.
+*   `redirect_to_phone` (String): The phone number to redirect calls to.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.create_sip(name: 'My SIP')
+```
+
+## `password(sip:, value:)`
+
+Change the password for a SIP number.
+
+**Parameters:**
+
+*   `sip` (String): The SIP number.
+*   `value` (String): The new password.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.set_sip_password(sip: '123', value: 'new_password')
+```
diff --git a/mkdocs/sms.md b/mkdocs/sms.md
new file mode 100644
index 0000000..dad4fc4
--- /dev/null
+++ b/mkdocs/sms.md
@@ -0,0 +1,23 @@
+# SMS Resource
+
+The SMS resource allows you to send SMS messages.
+
+## `send_sms(number:, message:, sender: nil)`
+
+Send an SMS message.
+
+**Parameters:**
+
+*   `number` (String): The destination phone number.
+*   `message` (String): The SMS message text.
+*   `sender` (String): The SMS sender (virtual number or text).
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.send_sms(number: '1234567890', message: 'Hello, world!')
+```
diff --git a/mkdocs/speech_recognition.md b/mkdocs/speech_recognition.md
new file mode 100644
index 0000000..667b9b3
--- /dev/null
+++ b/mkdocs/speech_recognition.md
@@ -0,0 +1,43 @@
+# Speech Recognition Resource
+
+The Speech Recognition resource allows you to manage speech recognition.
+
+## `get(call_id:, lang: nil, return_results: nil, alternatives: nil)`
+
+Get recognition results.
+
+**Parameters:**
+
+*   `call_id` (String): The unique call ID.
+*   `lang` (String): The recognition language.
+*   `return_results` (String): The returned result ('words' or 'phrases').
+*   `alternatives` (String): Return alternative results ('0' or '1').
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.get_speech_recognition(call_id: '12345')
+```
+
+## `initiate(call_id:, lang: nil)`
+
+Initiate call recognition.
+
+**Parameters:**
+
+*   `call_id` (String): The unique call ID.
+*   `lang` (String): The recognition language.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.initiate_speech_recognition(call_id: '12345')
+```
diff --git a/mkdocs/statistics.md b/mkdocs/statistics.md
new file mode 100644
index 0000000..427bda4
--- /dev/null
+++ b/mkdocs/statistics.md
@@ -0,0 +1,39 @@
+# Statistics Resource
+
+The Statistics resource provides access to call statistics.
+
+## `statistics(params)`
+
+Get overall call statistics.
+
+**Parameters:**
+
+*   `params` (Hash): The parameters for the statistics request.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.statistics(start: '2023-01-01', end: '2023-01-31')
+```
+
+## `pbx_statistics(params)`
+
+Get PBX call statistics.
+
+**Parameters:**
+
+*   `params` (Hash): The parameters for the PBX statistics request.
+
+**Returns:**
+
+A `Hash` containing the API response.
+
+**Example:**
+
+```ruby
+client.pbx_statistics(start: '2023-01-01', end: '2023-01-31')
+```
diff --git a/zadarma.gemspec b/zadarma.gemspec
index d071dee..2aff6eb 100644
--- a/zadarma.gemspec
+++ b/zadarma.gemspec
@@ -23,4 +23,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'rubocop', '~> 1.0'
   s.add_development_dependency 'rubocop-rspec', '~> 2.0'
   s.add_development_dependency 'webmock', '~> 3.0'
+  s.add_development_dependency 'yard', '~> 0.9'
 end