Hello World

Greet a user based on time of day. Demonstrates sequence, selector, and action primitives.

Version: 2.0.0

Files

• hello-world/TREE.yaml — main

Install

mkdir -p .abtree/trees/hello-world \
  && curl -fsSL https://raw.githubusercontent.com/flying-dice/abtree/main/.abtree/trees/hello-world/TREE.yaml \
         -o .abtree/trees/hello-world/TREE.yaml

Run with Claude

claude "Run the abtree hello-world tree. Use 'abtree --help' to learn the execution protocol, then create an execution with 'abtree execution create hello-world \"<summary>\"' and drive it to completion."

---

Tree definition

# yaml-language-server: $schema=https://abtree.dev/schemas/tree.schema.json
name: hello-world
version: 2.0.0
description: Greet a user based on time of day. Demonstrates sequence, selector, and action primitives.

state:
  local:
    time_of_day: null
    greeting: null
  global:
    user_name: retrieve by running the shell command "whoami"
    tone: friendly
    language: english

tree:
  type: sequence
  name: Hello_World
  children:
    - type: action
      name: Determine_Time
      steps:
        - instruct: >
            Check the system clock to get the current hour.
            Classify as: before 12:00 = "morning", 12:00-17:00 = "afternoon", after 17:00 = "evening".
            Store the classification string at $LOCAL.time_of_day.

    - type: selector
      name: Choose_Greeting
      children:
        - type: action
          name: Morning_Greeting
          steps:
            - evaluate: $LOCAL.time_of_day is "morning"
            - instruct: >
                Compose a cheerful morning greeting addressing $GLOBAL.user_name
                in $GLOBAL.language with a $GLOBAL.tone tone.
                Store at $LOCAL.greeting.

        - type: action
          name: Afternoon_Greeting
          steps:
            - evaluate: $LOCAL.time_of_day is "afternoon"
            - instruct: >
                Compose a warm afternoon greeting addressing $GLOBAL.user_name
                in $GLOBAL.language with a $GLOBAL.tone tone.
                Store at $LOCAL.greeting.

        - type: action
          name: Evening_Greeting
          steps:
            - evaluate: $LOCAL.time_of_day is "evening"
            - instruct: >
                Compose a relaxed evening greeting addressing $GLOBAL.user_name
                in $GLOBAL.language with a $GLOBAL.tone tone.
                Store at $LOCAL.greeting.

        - type: action
          name: Default_Greeting
          steps:
            - instruct: >
                Compose a neutral greeting addressing $GLOBAL.user_name
                in $GLOBAL.language with a $GLOBAL.tone tone.
                Store at $LOCAL.greeting.