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Colang 2.0 Overview

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Version Timeline

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What’s New in 2.0

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Colang 2.0-alpha Features

• More powerful flows engine: Supports multiple parallel flows and advanced pattern matching over event streams
• Standard library: Simplifies bot development with pre-built flows
• Smaller set of core abstractions: Flows, events, and actions
• Explicit entry point: Through the main flow with explicit activation
• Asynchronous actions: Non-blocking action execution
• Python-like syntax: Reduced learning curve for developers

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Colang 2.0-beta Additions

• Import mechanism: For the standard library to streamline development
• Generation operator (...): Dynamic runtime generation using LLMs
• Standalone and flow parameter expression evaluation: More flexible parameter handling

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Current Limitations

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Major Changes from 1.0

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Terminology

• Every bit of Colang code is called a script
• A single .co file is called a module
• A folder of Colang files is called a package
• Modules and packages can be imported

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Syntax Changes

• define - No longer needed
• execute - Replaced with await

• flow - Define flows (replaces define flow)
• match - Match events
• send - Send events
• start - Start flows/actions without waiting
• await - Start and wait for completion
• activate - Activate flows to run in background

• Support for decorators (e.g., @active)
• when/or when instead of when/else when
• Dropped subflows (use regular flows instead)

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Defining User and Bot Intents

define user express greeting
  "hi"
  "hello"

define bot express greeting
  "Hello there!"

flow user expressed greeting
  user said "hi" or user said "hello"

flow bot express greeting
  bot say "Hello world!"
    or bot say "Hi there!"

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Flow Naming Conventions

• User flows (events from outside): Use past tense (e.g., user said, user expressed greeting)
• Bot flows (actions to take): Use imperative form (e.g., bot say, bot express greeting, bot refuse to respond)

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The Generation Operator

flow check user utterance $input_text -> $input_safe
  $is_safe = ..."Consider the following user utterance: '{$input_text}'. Assign 'True' if appropriate, 'False' if inappropriate."
  return $is_safe

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Active Flows and Entry Point

• The main flow is the entry point
• Flows must be activated explicitly
• Use activate to enable flows

import core
import llm

flow main
  activate llm continuation
  activate greeting

flow greeting
  user expressed greeting
  bot express greeting

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Import Mechanism

import core
import llm
import guardrails

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Standard Library

• core: Core flows for user and bot utterances (e.g., user said, bot say)
• llm: Flows for LLM-driven interactions
• timing: Time-dependent flows (e.g., wait, user was silent $time_s)
• guardrails: Support for adding guardrails (input/output checking)
• avatars: Support for controlling interactive avatars
• utils: Utility flows

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Event-Driven Interaction Model

• User saying something generates events
• LLM generating a response creates events
• Triggering an action produces events
• Action results are events
• Guardrail triggers are events

[User Input] → [Event Stream] → [Guardrails Layer] → [LLM] → [Event Stream] → [Bot Output]
                     ↓                                           ↓
                [Pattern Matching]                         [Response Generation]

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Runtime Improvements

• No explicit state object
• Performance degrades with many events
• No support for parallel flows

• Explicit state management
• Better performance with large event streams
• Native support for parallel flows
• Advanced pattern matching
• Asynchronous action execution

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Use Cases

1. Multi-modal interactions: Voice, gestures, posture, images
2. Interactive avatars: Coordinating speech, gestures, and expressions
3. Complex agents: Multiple concurrent action streams
4. Real-time systems: Efficient event processing
5. Natural language workflows: Using the ... operator for LLM generation

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Migration Path

nemoguardrails convert "path/to/config" --from-version "1.0"

nemoguardrails convert "path/to/config" --from-version "2.0-alpha"

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When to Use Colang 2.0

• ✅ Parallel flows and concurrent actions
• ✅ Multi-modal interactions
• ✅ Better performance with many events
• ✅ Natural language generation with ...
• ✅ Modern Python-like syntax
• ✅ Standard library flows

• ✅ You have existing 1.0 configurations working well
• ✅ You need fully stable, production-tested features
• ✅ Your use case is simple text-based guardrails

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Next Steps