Skip to content

Fetch assistant prompt configuration from Langfuse #177

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
wants to merge 4 commits into
base: main
Choose a base branch
from
+151 −9
Draft

Fetch assistant prompt configuration from Langfuse #177

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
099b937
Fetch Langfuse prompt for assistant instructions
jjmata Oct 1, 2025
d8804ea
Handle nil values when compiling Langfuse instructions
jjmata Oct 1, 2025
17f5c02
Fixes and prompt support
jjmata Oct 1, 2025
805d405
Fix {{variable}} replacement
jjmata Oct 1, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 10 additions & 3 deletions app/models/assistant.rb
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,18 +1,24 @@
class Assistant
include Provided, Configurable, Broadcastable

attr_reader :chat, :instructions
attr_reader :chat, :instructions, :instructions_prompt

class << self
def for_chat(chat)
config = config_for(chat)
new(chat, instructions: config[:instructions], functions: config[:functions])
new(
chat,
instructions: config[:instructions],
instructions_prompt: config[:instructions_prompt],
functions: config[:functions]
)
end
end

def initialize(chat, instructions: nil, functions: [])
def initialize(chat, instructions: nil, instructions_prompt: nil, functions: [])
@chat = chat
@instructions = instructions
@instructions_prompt = instructions_prompt
@functions = functions
end

Expand All @@ -26,6 +32,7 @@ def respond_to(message)
responder = Assistant::Responder.new(
message: message,
instructions: instructions,
instructions_prompt: instructions_prompt,
function_tool_caller: function_tool_caller,
llm: get_model_provider(message.ai_model)
)
Expand Down
83 changes: 82 additions & 1 deletion app/models/assistant/configurable.rb
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,8 +6,11 @@ def config_for(chat)
preferred_currency = Money::Currency.new(chat.user.family.currency)
preferred_date_format = chat.user.family.date_format

instructions_config = default_instructions(preferred_currency, preferred_date_format)

{
instructions: default_instructions(preferred_currency, preferred_date_format),
instructions: instructions_config[:content],
instructions_prompt: instructions_config[:prompt],
functions: default_functions
}
end
Expand All @@ -23,6 +26,75 @@ def default_functions
end

def default_instructions(preferred_currency, preferred_date_format)
langfuse_instructions = langfuse_default_instructions(preferred_currency, preferred_date_format)

if langfuse_instructions.present?
{
content: langfuse_instructions[:content],
prompt: langfuse_instructions
}
else
{
content: fallback_default_instructions(preferred_currency, preferred_date_format),
prompt: nil
}
end
end

def langfuse_default_instructions(preferred_currency, preferred_date_format)
return unless langfuse_client

prompt = langfuse_client.get_prompt("default_instructions")
return if prompt.nil?
compiled_prompt = compile_langfuse_prompt(
prompt,
preferred_currency: preferred_currency,
preferred_date_format: preferred_date_format
)

content = extract_prompt_content(compiled_prompt)
return if content.blank?

{
name: prompt.name,
version: prompt.version,
template: prompt.prompt,
content: content
}
rescue => e
Rails.logger.warn("Langfuse prompt retrieval failed: #{e.message}")
nil
end

def compile_langfuse_prompt(prompt, preferred_currency:, preferred_date_format:)
variables = {
preferred_currency_symbol: preferred_currency&.symbol,
preferred_currency_iso_code: preferred_currency&.iso_code,
preferred_currency_default_precision: preferred_currency&.default_precision,
preferred_currency_default_format: preferred_currency&.default_format,
preferred_currency_separator: preferred_currency&.separator,
preferred_currency_delimiter: preferred_currency&.delimiter,
preferred_date_format: preferred_date_format,
current_date: Date.current
}.transform_values { |value| value.nil? ? "" : value.to_s }

prompt.compile(**variables)
end

def extract_prompt_content(compiled_prompt)
case compiled_prompt
when String
compiled_prompt
when Array
compiled_prompt.filter_map do |message|
message[:content] || message["content"]
end.join("\n\n")
else
nil
end
end

def fallback_default_instructions(preferred_currency, preferred_date_format)
<<~PROMPT
## Your identity

Expand Down Expand Up @@ -78,5 +150,14 @@ def default_instructions(preferred_currency, preferred_date_format)
the data you're presenting represents and what context it is in (i.e. date range, account, etc.)
PROMPT
end

def langfuse_client
return unless ENV["LANGFUSE_PUBLIC_KEY"].present? && ENV["LANGFUSE_SECRET_KEY"].present?

@langfuse_client ||= Langfuse.new
rescue => e
Rails.logger.warn("Langfuse client initialization failed: #{e.message}")
nil
end
Comment on lines +183 to +190
Copy link

@coderabbitai coderabbitai bot Oct 1, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

🛠️ Refactor suggestion | 🟠 Major

Extract duplicated langfuse_client to a shared concern.

This method is nearly identical to Provider::OpenAI#langfuse_client (lines 140-144 in app/models/provider/openai.rb). To follow DRY principles and maintain consistency, consider extracting this to a shared concern (e.g., LangfuseClientConcern) that both classes can include.

Create a new concern at app/models/concerns/langfuse_client_concern.rb:

module LangfuseClientConcern
  extend ActiveSupport::Concern

  class_methods do
    def langfuse_client
      return unless ENV["LANGFUSE_PUBLIC_KEY"].present? && ENV["LANGFUSE_SECRET_KEY"].present?

      @langfuse_client ||= Langfuse.new
    rescue => e
      Rails.logger.warn("Langfuse client initialization failed: #{e.message}")
      nil
    end
  end
end

Then include it in both Assistant::Configurable and Provider::OpenAI:

 module Assistant::Configurable
   extend ActiveSupport::Concern
+  include LangfuseClientConcern

   class_methods do
     # ...
-
-      def langfuse_client
-        return unless ENV["LANGFUSE_PUBLIC_KEY"].present? && ENV["LANGFUSE_SECRET_KEY"].present?
-
-        @langfuse_client ||= Langfuse.new
-      rescue => e
-        Rails.logger.warn("Langfuse client initialization failed: #{e.message}")
-        nil
-      end
   end
 end

As per coding guidelines.

🤖 Prompt for AI Agents 
In app/models/assistant/configurable.rb around lines 154 to 161 and
app/models/provider/openai.rb around lines 140 to 144, the langfuse_client
method is duplicated; extract it into a new concern at
app/models/concerns/langfuse_client_concern.rb that defines the class-level
langfuse_client (using ActiveSupport::Concern with class_methods), move the
existing implementation there (keeping the same ENV checks, memoization and
rescue logging), then remove the method from both Assistant::Configurable and
Provider::OpenAI and include the new LangfuseClientConcern in each class so they
share the single implementation.

end
end
6 changes: 4 additions & 2 deletions app/models/assistant/responder.rb
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,9 +1,10 @@
class Assistant::Responder
def initialize(message:, instructions:, function_tool_caller:, llm:)
def initialize(message:, instructions:, function_tool_caller:, llm:, instructions_prompt: nil)
@message = message
@instructions = instructions
@function_tool_caller = function_tool_caller
@llm = llm
@instructions_prompt = instructions_prompt
end

def on(event_name, &block)
Expand Down Expand Up @@ -31,7 +32,7 @@ def respond(previous_response_id: nil)
end

private
attr_reader :message, :instructions, :function_tool_caller, :llm
attr_reader :message, :instructions, :function_tool_caller, :llm, :instructions_prompt

def handle_follow_up_response(response)
streamer = proc do |chunk|
Expand Down Expand Up @@ -64,6 +65,7 @@ def get_llm_response(streamer:, function_results: [], previous_response_id: nil)
message.content,
model: message.ai_model,
instructions: instructions,
instructions_prompt: instructions_prompt,
functions: function_tool_caller.function_definitions,
function_results: function_results,
streamer: streamer,
Expand Down
1 change: 1 addition & 0 deletions app/models/provider/llm_concept.rb
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@ def chat_response(
prompt,
model:,
instructions: nil,
instructions_prompt: nil,
functions: [],
function_results: [],
streamer: nil,
Expand Down
60 changes: 39 additions & 21 deletions app/models/provider/openai.rb
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,7 @@
prompt,
model:,
instructions: nil,
instructions_prompt: nil,
functions: [],
function_results: [],
streamer: nil,
Expand Down Expand Up @@ -112,6 +113,7 @@
model: model,
input: input_payload,
output: response.messages.map(&:output_text).join("\n"),
prompt: instructions_prompt,
session_id: session_id,
user_identifier: user_identifier
)
Expand All @@ -123,6 +125,7 @@
model: model,
input: input_payload,
output: parsed.messages.map(&:output_text).join("\n"),
prompt: instructions_prompt,
usage: raw_response["usage"],
session_id: session_id,
user_identifier: user_identifier
Expand All @@ -141,26 +144,41 @@
@langfuse_client = Langfuse.new
end

def log_langfuse_generation(name:, model:, input:, output:, usage: nil, session_id: nil, user_identifier: nil)
return unless langfuse_client

trace = langfuse_client.trace(
name: "openai.#{name}",
input: input,
session_id: session_id,
user_id: user_identifier
)
trace.generation(
name: name,
model: model,
input: input,
output: output,
usage: usage,
session_id: session_id,
user_id: user_identifier
)
trace.update(output: output)
rescue => e
Rails.logger.warn("Langfuse logging failed: #{e.message}")
def log_langfuse_generation(name:, model:, input:, output:, usage: nil, session_id: nil, user_identifier: nil, prompt: nil)

Check failure on line 147 in app/models/provider/openai.rb

View workflow job for this annotation

GitHub Actions / ci / lint 

Layout/IndentationConsistency: Inconsistent indentation detected.
Copy link

@coderabbitai coderabbitai bot Oct 1, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🟡 Minor

Fix indentation to align with Ruby style guidelines.

The method definition has inconsistent indentation.

Apply this diff:

-  def log_langfuse_generation(name:, model:, input:, output:, usage: nil, session_id: nil, user_identifier: nil, prompt: nil)
+def log_langfuse_generation(name:, model:, input:, output:, usage: nil, session_id: nil, user_identifier: nil, prompt: nil)

Based on static analysis hints.

📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
def log_langfuse_generation(name:, model:, input:, output:, usage: nil, session_id: nil, user_identifier: nil, prompt: nil)
def log_langfuse_generation(name:, model:, input:, output:, usage: nil, session_id: nil, user_identifier: nil, prompt: nil)
🧰 Tools
🪛 GitHub Check: ci / lint

[failure] 147-147:
Layout/IndentationConsistency: Inconsistent indentation detected.

🤖 Prompt for AI Agents 
In app/models/provider/openai.rb around line 147, the method definition `def
log_langfuse_generation...` is indented inconsistently; reformat the line to
follow Ruby style (2-space indentation) so it aligns with the other method
definitions in the class/module scope — move the `def` left to the same
indentation level as neighboring methods and ensure the parameter list and
closing `end` remain aligned accordingly.

return unless langfuse_client

trace = langfuse_client.trace(
name: "openai.#{name}",
input: input,
session_id: session_id,
user_id: user_identifier
)
generation_options = {
name: name,
model: model,
input: input,
output: output,
usage: usage,
session_id: session_id,
user_id: user_identifier
}

if prompt.present?
generation_options[:version] = prompt[:version] if prompt[:version]
metadata = {
prompt: {
name: prompt[:name],
version: prompt[:version],
content: prompt[:content],
template: prompt[:template]
}.compact
}
generation_options[:metadata] = metadata
end

trace.generation(**generation_options)
trace.update(output: output)
rescue => e
Rails.logger.warn("Langfuse logging failed: #{e.message}")
end
end
Loading