Class: TalkToYourApp::Plugins::Db::Plugin

Inherits:
TalkToYourApp::Plugin show all
Defined in:
lib/talk_to_your_app/plugins/db/plugin.rb

Overview

The DB plugin: SQL plus schema introspection against an operator-wired connection (config.plugin :db, connection: :read). Wired to a :reading connection (the default role) it is read-only — Rails' write prevention plus the DB role reject writes. Wired to a :writing connection it can execute writes; that is a deliberate, documented opt-in (see README).

Class Method Summary collapse

Methods inherited from TalkToYourApp::Plugin

log_level, requires_gem, tools, wired_spec

Class Method Details

.describe_tool(tool_class) ⇒ Object

When wired to a writable connection, advertise that on the db.query tool so an MCP client can tell a write-capable deployment apart from a read-only one. Returns nil (use the tool's own description) otherwise.



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# File 'lib/talk_to_your_app/plugins/db/plugin.rb', line 58

def self.describe_tool(tool_class)
  return unless tool_class == Tools::Query

  conn = TalkToYourApp.configuration.enabled_plugins.dig(:db, :connection)
  return unless conn && TalkToYourApp::ConnectionRegistry.registered?(conn)
  return if TalkToYourApp::ConnectionRegistry.fetch(conn).reading?

  "Run a SQL query and return the rows. This connection is WRITABLE — " \
    "UPDATE/INSERT/DELETE/DDL statements will execute."
end

.validate_enablement!(options) ⇒ Object

The DB plugin needs a real connection — connection: false is invalid. Branch on the wired role: a :reading connection keeps the read-only guarantee (boot silently); a :writing connection enables writes through db.query — permitted, but warned loudly. The warning is detection/audit only; the real safeguard is that the operator had to both declare a role: :writing connection and wire it here.



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# File 'lib/talk_to_your_app/plugins/db/plugin.rb', line 44

def self.validate_enablement!(options)
  unless options[:connection]
    raise TalkToYourApp::ConfigurationError,
      "talk_to_your_app: the DB plugin requires a real connection — " \
      "`config.plugin :db, connection: :your_connection`. `connection: false` is not valid."
  end

  spec = wired_spec(options) # nil for an unregistered name (ConnectionRegistry.validate! owns that)
  warn_writable(spec.name) if spec && !spec.reading?
end