dagstack-config

Python binding for dagstack/config-spec — YAML configuration with env interpolation, deep-merge layering, Pydantic-based typed sections, runtime reconfigure.

Status: Phase A (skeleton). Implementation in progress — see open issues.

Roadmap

• Phase A (this PR) — repo skeleton, pyproject, CI, spec submodule, empty package.
• Phase B — core primitives: ConfigError + reasons, env interpolation parser, deep merge, Canonical JSON serializer.
• Phase C — Config class, ConfigSource abstraction (YamlFileSource, JsonFileSource, InMemorySource), Subscription handle.
• Phase D — conformance runner against spec/conformance/ golden fixtures.
• Phase 1 release (0.1.0) — after Phase A-D merge. Spec MVP (no watch, hot-reload, OTLP-source, etc.).
• Phase 2+ — source adapters (etcd, Consul, Vault, HTTP), watch + push-reload, LogProcessor-like hooks.

Spec

The spec submodule lives in spec/ (pointing to dagstack/config-spec). Normative decisions are recorded in spec/adr/0001-yaml-configuration.md.

Local development

git clone --recurse-submodules git@github.com:dagstack/config-python.git
cd config-python
uv sync --group dev

make test           # pytest
make lint           # ruff check + format --check
make typecheck      # mypy --strict

Licensing

Apache-2.0 (see LICENSE).

Related

• dagstack/config-spec — language-agnostic spec.
• dagstack/logger-spec — logger that reads config through this binding.
• dagstack/plugin-system-python — reference binding (pattern and Makefile/CI structure).