cscm

cscm is a compiler/toolchain for a small configuration-schema definition language. A .cscm file is the single source of truth for a config schema; cscm generates model classes in a target language (currently Python) that load, save, and validate real config files (JSON/YAML) against that schema.

server:
    host: String = "127.0.0.1"
    port: Int(min=1, max=65535) = 8080
    tls:
        enabled: Bool = false

Install

cargo install cscm

pip install cscm

Or download a prebuilt binary from the GitHub Releases page (Linux/macOS/Windows, x86_64 + aarch64).

Usage

cscm schema.cscm --lang python -o config.py

• --lang and -o are each independently optional: --lang is inferred from -o's extension (.py → python) if omitted; if both are omitted it's an error. If -o is omitted, generated code is written to stdout instead of a file.

The generated Python module is a plain dataclass-based API:

from config import Config

cfg = Config.load("config.yaml")   # detects JSON vs YAML from the extension; validates on load
cfg.server.port                    # typed, validated access
cfg.save("config.yaml")

Generated code depends on a small shared runtime package at load/save time:

pip install cscm-runtime

Language

• Indentation-based nesting (spaces only, no tabs).
• # line comments.
• Types: Bool, Int, Float, String, List<T>, Map<T> (T a scalar type; Map keys are always String). Nested indented blocks are the only way to express structure.
• Constraints as call-like arguments on the type: Int(min=1, max=65535), String(max=64), String(pattern="[a-z]+").
• Type? makes a field's value nullable; = default makes the field optional to omit from the config file. The two are independent — see CLAUDE.md for the full grammar and all four combinations.

See sample/web.cscm for a larger example covering every type/constraint combination.

Development

cargo build
cargo test
cargo run -- sample/web.cscm -o /tmp/config.py

See CLAUDE.md for full architecture notes, the generator's semantic-check rules, and current distribution/publishing status.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.