depvex

depvex generates and checks requirements.txt files from static Python imports. It is designed for a single Python application and for repositories that contain multiple independently managed services.

Core capabilities

• AST-based detection of import and from ... import ... statements.
• Standard-library filtering and per-import opt-out with # ignore depvex.
• Recursive Python-file discovery with built-in ignored directories and YAML ignore_dirs support.
• Import-module to installed-distribution mapping through importlib.metadata.
• Version lookup from installed metadata without subprocesses, followed by an optional PyPI fallback.
• Existing dependency pins are retained when the package remains in use; stale entries are removed during a scan.
• One-time scan, CI-oriented check, and debounced filesystem watch mode.
• Per-service requirements files plus a root requirements file for microservice repositories.

Install

Requires Python 3.11+.

python -m pip install depvex

Install PyYAML separately to enable depvex.yaml or depvex.yml:

python -m pip install PyYAML

Intended command interface

depvex --scan .
depvex --check .
depvex --watch .

• --scan updates requirements files.
• --check returns exit code 0 when requirements files match the detected imports and 1 otherwise.
• --watch performs an initial scan and updates files after created or modified Python-file events.

Version note

The new source interface above is not compatible with the older published package, which uses positional commands such as depvex check .. The current source also needs its command dispatcher aligned with the new option-style names before those commands can execute correctly. Install and invoke one version consistently in CI.

Single application

Without configured services, scanning a directory creates or updates its single requirements.txt:

depvex --scan ./my-app

Microservices

Define direct child service folders in depvex.yaml:

micro_servi_folders:
  - api
  - worker

ignore_dirs:
  - tests

Scanning the repository produces:

repository/
├── api/requirements.txt
├── worker/requirements.txt
└── requirements.txt

The root file covers Python files outside api and worker; service-only imports are excluded from it. Watch mode rescans only the affected service when a file changes below a configured service folder.

The current key spelling is micro_servi_folders, and service configuration is read from YAML only. config.json is used for CAPTIVE_PORTAL_URLS and debounce_seconds, not service discovery.

CI

Install the target project's dependencies and the checked-out project before checking, so package metadata is available and the local code is executed:

- run: |
    python -m pip install -r requirements.txt
    python -m pip install .
- run: depvex --check .

check currently reports only an out-of-date result. Run scan, review the requirements diff, and commit expected changes.

Scope and roadmap

Depvex does not resolve dynamic imports or replace a lockfile manager. Its next goals are consistent scan/check calculations, actionable dependency diffs, a canonical microservice configuration key, and automated tests for single-project, microservice, watch, and CI scenarios.