/ 
Langertha-0.100
River stage zero No dependents
/ Langertha::Role::Tools

NAME

Langertha::Role::Tools - Role for MCP tool calling support

VERSION

version 0.100

SYNOPSIS

use IO::Async::Loop;
use Net::Async::MCP;
use Future::AsyncAwait;

my $loop = IO::Async::Loop->new;

# Set up an MCP server with tools
my $mcp = Net::Async::MCP->new(server => $my_mcp_server);
$loop->add($mcp);
await $mcp->initialize;

# Create engine with MCP servers
my $engine = Langertha::Engine::Anthropic->new(
  api_key     => $ENV{ANTHROPIC_API_KEY},
  model       => 'claude-sonnet-4-5-20250929',
  mcp_servers => [$mcp],
);

# Async tool-calling chat loop
my $response = await $engine->chat_with_tools_f(
  'Use the available tools to answer my question'
);

DESCRIPTION

This role adds MCP (Model Context Protocol) tool calling support to Langertha engines. It provides the chat_with_tools_f method which implements the full async tool-calling loop:

1. Gather available tools from all configured MCP servers
2. Send chat request with tool definitions to the LLM
3. If the LLM returns tool calls, execute them via MCP
4. Feed tool results back to the LLM and repeat
5. When the LLM returns final text, return it

Engines that compose this role must implement four methods to handle the engine-specific tool format conversion. See "REQUIRED METHODS".

REQUIRED METHODS

Engines composing this role must implement:

format_tools(\@mcp_tools)

Convert MCP tool definitions to the engine's native tool format.

response_tool_calls(\%response_data)

Extract tool call objects from a parsed LLM response.

format_tool_results(\%response_data, \@results)

Format tool execution results as messages to append to the conversation.

response_text_content(\%response_data)

Extract the final text content from a parsed LLM response.

mcp_servers

mcp_servers => [$mcp1, $mcp2]

ArrayRef of Net::Async::MCP instances to use as tool providers.

tool_max_iterations

tool_max_iterations => 20

Maximum number of tool-calling round trips before aborting. Defaults to 10.

chat_with_tools_f

my $response = await $engine->chat_with_tools_f(@messages);

Async tool-calling chat loop. Accepts the same message arguments as simple_chat. Returns a Future that resolves to the final text response after all tool calls have been executed.

SEE ALSO

SUPPORT

Issues

Please report bugs and feature requests on GitHub at https://github.com/Getty/langertha/issues.

CONTRIBUTING

Contributions are welcome! Please fork the repository and submit a pull request.

AUTHOR

Torsten Raudssus <torsten@raudssus.de> https://raudss.us/

COPYRIGHT AND LICENSE

This software is copyright (c) 2026 by Torsten Raudssus.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.