diff --git a/enterprise/app/services/captain/assistant/base_rewrite_service.rb b/enterprise/app/services/captain/assistant/base_rewrite_service.rb
new file mode 100644
index 000000000..a131868d7
--- /dev/null
+++ b/enterprise/app/services/captain/assistant/base_rewrite_service.rb
@@ -0,0 +1,95 @@
+require 'agents'
+
+class Captain::Assistant::BaseRewriteService
+  def initialize(text:)
+    @text = text
+  end
+
+  def execute
+    agent = build_agent
+    runner = Agents::Runner.with_agents(agent)
+
+    result = runner.run(@text)
+
+    # Check if result has an error field
+    return error_response(result.error) if result.respond_to?(:error) && result.error
+
+    process_result(result)
+  rescue StandardError => e
+    Rails.logger.error "[Captain V2] #{self.class.name} error: #{e.message}"
+    Rails.logger.error e.backtrace.join("\n")
+
+    error_response(e.message)
+  end
+
+  protected
+
+  def build_agent
+    Agents::Agent.new(
+      name: agent_name,
+      instructions: build_instructions,
+      model: agent_model,
+      response_schema: response_schema
+    )
+  end
+
+  def agent_model
+    InstallationConfig.find_by(name: 'CAPTAIN_OPEN_AI_MODEL')&.value.presence || OpenAiConstants::DEFAULT_MODEL
+  end
+
+  # To be implemented by subclasses
+  def agent_name
+    raise NotImplementedError, "#{self.class} must implement agent_name"
+  end
+
+  def build_instructions
+    raise NotImplementedError, "#{self.class} must implement build_instructions"
+  end
+
+  def response_schema
+    raise NotImplementedError, "#{self.class} must implement response_schema"
+  end
+
+  def process_result(result)
+    output = result.output
+
+    # Check if output itself has an error
+    return error_response(output[:error] || output['error']) if output.is_a?(Hash) && (output[:error] || output['error'])
+
+    build_success_response(output)
+  end
+
+  # Override in subclasses for custom response structure
+  def build_success_response(output)
+    {
+      success: true,
+      result: extract_primary_field(output),
+      original_text: @text
+    }
+  end
+
+  def error_response(error_message)
+    {
+      success: false,
+      error: error_message,
+      original_text: @text
+    }
+  end
+
+  # Helper methods for extracting data from output
+  def extract_field(output, *field_names)
+    return output.to_s unless output.is_a?(Hash)
+
+    field_names.each do |field|
+      value = output[field.to_sym] || output[field.to_s]
+      return value if value
+    end
+
+    nil
+  end
+
+  # Override in subclasses to specify the primary field to extract
+  def extract_primary_field(output)
+    output
+  end
+end
diff --git a/enterprise/app/services/captain/assistant/change_tone_service.rb b/enterprise/app/services/captain/assistant/change_tone_service.rb
new file mode 100644
index 000000000..13468d1a8
--- /dev/null
+++ b/enterprise/app/services/captain/assistant/change_tone_service.rb
@@ -0,0 +1,56 @@
+class Captain::Assistant::ChangeToneService < Captain::Assistant::BaseRewriteService
+  SUPPORTED_TONES = %w[professional casual straightforward confident friendly].freeze
+
+  def initialize(text:, tone:)
+    super(text: text)
+    @tone = validate_tone(tone)
+  end
+
+  protected
+
+  def agent_name
+    'ToneChanger'
+  end
+
+  def build_instructions
+    context = { tone: @tone }
+    Captain::PromptRenderer.render('rewrite/tone', context.with_indifferent_access)
+  end
+
+  def response_schema
+    {
+      type: 'object',
+      properties: {
+        rewritten_text: {
+          type: 'string',
+          description: 'The rewritten text with the requested tone applied'
+        },
+        tone_applied: {
+          type: 'string',
+          description: 'The tone that was applied to the text'
+        }
+      },
+      required: %w[rewritten_text tone_applied],
+      additionalProperties: false
+    }
+  end
+
+  def build_success_response(output)
+    {
+      success: true,
+      rewritten_text: extract_field(output, 'rewritten_text'),
+      tone: @tone,
+      original_text: @text
+    }
+  end
+
+  private
+
+  def validate_tone(tone)
+    tone_str = tone.to_s.downcase
+
+    raise ArgumentError, "Unsupported tone: #{tone}. Supported tones: #{SUPPORTED_TONES.join(', ')}" unless SUPPORTED_TONES.include?(tone_str)
+
+    tone_str
+  end
+end
diff --git a/enterprise/app/services/captain/assistant/fix_grammar_service.rb b/enterprise/app/services/captain/assistant/fix_grammar_service.rb
new file mode 100644
index 000000000..c2fb4a3fe
--- /dev/null
+++ b/enterprise/app/services/captain/assistant/fix_grammar_service.rb
@@ -0,0 +1,49 @@
+class Captain::Assistant::FixGrammarService < Captain::Assistant::BaseRewriteService
+  protected
+
+  def agent_name
+    'GrammarFixer'
+  end
+
+  def build_instructions
+    Captain::PromptRenderer.render('rewrite/grammar', {})
+  end
+
+  def response_schema
+    {
+      type: 'object',
+      properties: {
+        corrected_text: {
+          type: 'string',
+          description: 'The text with corrected grammar, spelling, and punctuation'
+        },
+        corrections_made: {
+          type: 'array',
+          description: 'List of corrections that were made',
+          items: {
+            type: 'string'
+          }
+        }
+      },
+      required: ['corrected_text'],
+      additionalProperties: false
+    }
+  end
+
+  def build_success_response(output)
+    {
+      success: true,
+      corrected_text: extract_field(output, 'corrected_text'),
+      corrections_made: extract_corrections(output),
+      original_text: @text
+    }
+  end
+
+  private
+
+  def extract_corrections(output)
+    return [] unless output.is_a?(Hash)
+
+    output[:corrections_made] || output['corrections_made'] || []
+  end
+end
diff --git a/enterprise/lib/captain/prompts/rewrite/grammar.liquid b/enterprise/lib/captain/prompts/rewrite/grammar.liquid
new file mode 100644
index 000000000..4fa144f49
--- /dev/null
+++ b/enterprise/lib/captain/prompts/rewrite/grammar.liquid
@@ -0,0 +1,8 @@
+You are an expert writing editor. Rewrite the provided text to correct grammar, spelling, and punctuation while fully preserving the original meaning and style.
+
+Rules:
+• Preserve tone, language, formatting, structure, proper nouns, URLs, quotes, numbers, IDs, addresses.
+• Do not modify content inside code blocks or backticks.
+• Do not add content or opinions. Keep length similar.
+• Minimal edits if already correct.
+• Do not alter legal, medical, or compliance meaning.
diff --git a/enterprise/lib/captain/prompts/rewrite/tone.liquid b/enterprise/lib/captain/prompts/rewrite/tone.liquid
new file mode 100644
index 000000000..0680065a6
--- /dev/null
+++ b/enterprise/lib/captain/prompts/rewrite/tone.liquid
@@ -0,0 +1,17 @@
+You are an expert writing editor. Rewrite the provided text according to the selected tone while keeping the original intent.
+
+{% case tone %}
+{% when "professional" %}Rewrite in a formal and precise tone.
+{% when "casual" %}Rewrite in a relaxed and conversational tone.
+{% when "straightforward" %}Rewrite concise and direct. Remove filler.
+{% when "confident" %}Rewrite bold and assured.
+{% when "friendly" %}Rewrite warm and positive.
+{% else %}Rewrite to improve clarity and smoothness.
+{% endcase %}
+
+Rules:
+• Preserve original language, meaning, formatting, structure, proper nouns, URLs, quotes, numbers, IDs, addresses.
+• Do not modify content inside code blocks or backticks.
+• Do not add content or opinions. Keep length similar.
+• Minimal edits if already correct.
+• Do not alter legal, medical, or compliance meaning.