All notable changes to the Colang language and runtime will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

• Prompt template name to verbose logging (#811) by @schuellc-nvidia
• New configuration setting to change UMIM event source id (#823) by @sklinglernv
• New attention module to standard library (#829) by @sklinglernv
• Passthrough mode support (#779) by @Pouyanpi

• Activation of flows with default parameters (#758) by @schuellc-nvidia
• pretty_str string formatting function (#759) by @schuellc-nvidia
• Consistent uuid generation in debug mode (#760) by @schuellc-nvidia
• Avatar posture management function in standard library (#771) by @sklinglernv
• Nested if else construct parsing (#833) by @radinshayanfar
• Multiline string values in interaction history prompting (#765) by @radinshayanfar

• LLM prompt template generate_value_from_instruction for GTP and LLama model chat interface (#775) by @schuellc-nvidia

• Support for new Colang 2 keyword deactivate (#673) by @schuellc-nvidia
• Bot configuration as variable $system.config (#703) by @schuellc-nvidia
• Basic support for most OpenAI and LLame 3 models (#709) by @schuellc-nvidia
• Interaction loop priority levels for flows (#712) by @schuellc-nvidia
• CLI chat debugging commands (#717) by @schuellc-nvidia

• Merged (and removed) utils library file with core library (#669) by @schuellc-nvidia

• Fixes a event group match bug (e.g. match $flow_ref.Finished() or $flow_ref.Failed()) (#672) by @schuellc-nvidia
• Fix issues with ActionUpdated events and user utterance action extraction (#699) by @schuellc-nvidia

This second beta version of Colang brings a set of improvements and fixes.

Language and runtime:

• Colang 2.0 syntax error details (#504) by @rgstephens
• Expose global variables in prompting templates (#533) by @schuellc-nvidia
• continuation on unhandled user utterance flow to the standard library (llm.co) (#534) by @schuellc-nvidia
• Support for NLD intents (#554) by @schuellc-nvidia
• Support for the @active decorator which activates flows automatically (#559) by @schuellc-nvidia

Other:

• Unit tests for runtime exception handling in flows (#591) by @schuellc-nvidia

• Make if / while / when statements compatible with python syntax, i.e., allow : at the end of line (#576) by @schuellc-nvidia
• Allow not, in, is in generated flow names (#596) by @schuellc-nvidia
• Improve bot action generation (#578) by @schuellc-nvidia
• Add more information to Colang syntax errors (#594) by @schuellc-nvidia
• Runtime processing loop also consumes generated events before completion (#599) by @schuellc-nvidia
• LLM prompting improvements targeting gpt-4o (#540) by @schuellc-nvidia

• Fix string expression double braces (#525) by @schuellc-nvidia
• Fix Colang 2 flow activation (#531) by @schuellc-nvidia
• Remove unnecessary print statements in runtime (#577) by @schuellc-nvidia
• Fix match statement issue (#593) by @schuellc-nvidia
• Fix multiline string expressions issue (#579) by @schuellc-nvidia
• Fix tracking user talking state issue (#604) by @schuellc-nvidia
• Fix issue related to a race condition (#598) by @schuellc-nvidia

• Standard library of flows: core.co, llm.co, guardrails.co, avatars.co, timing.co, utils.co.

• Syntax changes:

  • Meta comments have been replaced by the @meta and @loop decorators:
    • # meta: user intent -> @meta(user_intent=True) (also user_action, bot_intent, bot_action)
    • # meta: exclude from llm -> @meta(exclude_from_llm=True)
    • # meta: loop_id=<loop_id> -> @loop("<loop_id>")
  • orwhen -> or when
  • NLD instructions """<NLD>""" -> ..."<NLD>"
  • Support for import statement
  • Regular expressions syntax change r"<regex>" -> regex("<regex>")
  • String expressions change: "{{<expression>}}" -> "{<expression>}"

• Chat CLI runtime flags --verbose logging format improvements

• Internal event parameter renaming: flow_start_uid -> flow_instance_uid

• Colang function name changes: findall -> find_all ,

• Changes to flow names that were previously part of ccl_*.co files (which are now part of the standard library):

  • catch colang errors -> notification of colang errors (core.co)
  • catch undefined flows -> notification of undefined flow start (core.co)
  • catch unexpected user utterance -> notification of unexpected user utterance (core.co)
  • poll llm request response -> polling llm request response (llm.co)
  • trigger user intent for unhandled user utterance -> generating user intent for unhandled user utterance (llm.co)
  • generate then continue interaction -> llm continue interaction (llm.co)
  • track bot talking state -> tracking bot talking state (core.co)
  • track user talking state -> tracking user talking state (core.co)
  • track unhandled user intent state -> tracking unhandled user intent state (llm.co)
  • track visual choice selection state -> track visual choice selection state (avatars.co)
  • track user utterance state -> tracking user talking state (core.co)
  • track bot utterance state -> No replacement yet (copy to your bot script)
  • interruption handling bot talking -> handling bot talking interruption (avatars.co)
  • generate then continue interaction -> llm continue interaction (llm.co)

Colang 2.0 represents a complete overhaul of both the language and runtime. Key enhancements include:

• A more powerful flows engine supporting multiple parallel flows and advanced pattern matching over the stream of events.
• A standard library to simplify bot development.
• Smaller set of core abstractions: flows, events, and actions.
• Explicit entry point through the main flow and explicit activation of flows.
• Asynchronous actions execution.
• Adoption of terminology and syntax akin to Python to reduce the learning curve for new developers.