Module: RailsAiContext::Tools::SafeCall

Defined in:
lib/rails_ai_context/tools/safe_call.rb

Overview

Last-resort rescue for tool execution, prepended to every registered tool's singleton class so it wraps each tool's self.call regardless of when the subclass defines the method.

Without this, an exception inside a tool escapes to the MCP SDK, which converts it into a JSON-RPC -32603 protocol error. Most AI clients swallow protocol errors, so the model never sees what went wrong and cannot recover. An error tool-result (isError: true) lands in the model's context instead, with enough detail to retry or route around the failure.

Instance Method Summary collapse

Instance Method Details

#call(**kwargs) ⇒ Object 



16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
 
# File 'lib/rails_ai_context/tools/safe_call.rb', line 16

def call(**kwargs)
  super
rescue StandardError => e
  # A failed call must not leak its recorded params into the next
  # call's session entry.
  Thread.current[:rails_ai_context_call_params] = nil

  label = respond_to?(:tool_name) ? tool_name : name
  origin = Array(e.backtrace).first.to_s
  text = +"Tool #{label} failed: #{e.class}: #{e.message.to_s.lines.first&.strip}\n"
  text << "At: #{origin}\n" unless origin.empty?
  text << "Recovery: retry with a narrower query (a single table, model, or " \
          "controller), or run `rails-ai-context doctor` to check app health."
  MCP::Tool::Response.new([ { type: "text", text: text } ], error: true)
end