Ezy

Ezy is a readable, deterministic scripting language for automation: files, processes, HTTP, and JSON as first-class citizens, with syntax that stays close to plain English without becoming a natural-language parser.

name = "World"
say "Hello, {name}!"

if file "config.json" exists
    config = parse_json(read "config.json")
    say config.name

response = get "https://api.example.com/users"
if response is successful
    for each user in response.json
        say user.name

Ezy does not depend on AI at runtime. The lexer, parser, and interpreter are fully deterministic Python code; there is no model in the execution path.

Installation

Requires Python 3.9+.

pip install -e .

This installs the ezy command (see pyproject.toml). The only runtime dependency is requests, used for the HTTP subsystem.

Quick start

ezy run examples/hello.ezy
ezy check examples/hello.ezy   # syntax check only, does not run
ezy repl                       # interactive session

File extensions .ezy and .ez are both accepted.

Linting

Ezy includes a static linter to catch common bugs before execution:

ezy lint script.ezy

The linter detects:

• [E101] Undefined variables
• [E102] Reassignment of constants
• [W202] Unused variables
• [W203] Unreachable code

Formatting

Ezy includes an AST-based formatter (ezy fmt) for the currently supported language constructs. It safely preserves comments by detecting their structural placement.

ezy fmt script.ezy

Check if a file requires formatting (useful for CI, exits 1 if unformatted):

ezy fmt --check script.ezy

Documentation

• docs/language.md — full language reference
• docs/architecture.md — how the interpreter is built
• docs/security.md — security model and review notes
• docs/limitations.md — honest list of what is not (yet) implemented, and deliberate deviations from a natural-language-style design
• examples/ — runnable example scripts

Development

pip install -e ".[dev]"   # or: pip install -e . pytest
python -m pytest tests/ -q

Project layout:

src/ezy/
  lexer.py        tokenizer (indentation-aware)
  parser.py       recursive-descent parser -> AST
  ast_nodes.py    AST node definitions
  interpreter.py  tree-walking evaluator, environments, builtins
  values.py       runtime value types (Function, HttpResponse, ...)
  stdlib/         files.py, process.py, http.py
  cli.py          `ezy` command (run / check / repl)
  repl.py         interactive shell
tests/            pytest suite (lexer, parser, interpreter, files,
                  process, http against a local test server, CLI)
examples/         runnable .ezy scripts
docs/             language reference, architecture, security, limitations

Status

This is a working v0.1 implementation of a real subset of the language described in the original design brief, not a mock or a proof of concept — every statement below docs/limitations.md's "Implemented" section runs and is covered by an automated test. See that file for what is partial or not yet built (a package registry, a formatter, a full point-free pipeline DSL, and a few others), and why.

CLI Scripts

Ezy allows you to create robust CLI applications effortlessly via the built-in cli statement. It automatically provides help text generation, type-checking, alias expansion, and argument parsing.

cli "deploy" desc "Deploy the application"
    flag "verbose" alias "v" desc "Enable verbose output"
    option "env" default "dev" desc "Deployment environment"

if cli.verbose
    say "Deploying to {cli.env}"

Simply run your script:

$ ezy run deploy.ezy --help
Usage: deploy [options] [--] [args...]

Deploy the application

Options:
  -v, --verbose      Enable verbose output
  -e, --env          Deployment environment (default: dev)
  -h, --help         Show this help message