reqsync

Keep your requirements.txt (and included requirement files) synced to what is actually installed — fast, safe, and low-effort.

Built for the "I just want my requirements file updated" workflow.

What reqsync is

reqsync reads your active environment and rewrites requirement specifiers so files reflect what you're currently running.

• Preserves comments, extras, markers, and line endings.
• Follows -r includes.
• Skips -c constraints unless you opt in.
• Uses backups + atomic writes.

What reqsync is not

• Not a lockfile manager.
• Not a dependency solver replacement.
• Not a hash-regenerator for --hash pinned lines.

Install

pip install reqsync

Optional extras:

pip install "reqsync[mcp]"      # built-in MCP server support
pip install "reqsync[pretty]"   # optional pretty ecosystem deps

Quick start

# 1) Preview only (no writes)
reqsync run --no-upgrade --dry-run --show-diff

# 2) Apply updates
reqsync run --show-diff

# 3) CI drift gate (fails if changes needed)
reqsync run --check --no-upgrade

Before / after example

# before
requests>=2.30.0
pydantic>=2.5.0

# after (installed env has requests 2.32.3, pydantic 2.7.0)
requests>=2.32.3
pydantic>=2.7.0

Terminal demos

Quick sync preview (--dry-run --show-diff)

CI check mode (--check --no-upgrade)

Integration Guide

Standalone usage

reqsync run --path requirements.txt
reqsync run --path requirements/base.txt --follow-includes

Agentic / MCP usage

# MCP server (stdio)
reqsync mcp

# or dedicated entrypoint
reqsync-mcp

Python API (tool-friendly)

from reqsync.api import run_sync_payload

result = run_sync_payload(
    {
        "path": "requirements.txt",
        "dry_run": True,
        "no_upgrade": True,
        "show_diff": True,
        "policy": "lower-bound",
    }
)
print(result["changed"])
print(result["changes"])

Core commands

reqsync run [OPTIONS]
reqsync help [all|run|version|mcp]
reqsync --version
reqsync version
reqsync mcp [--transport stdio|sse|streamable-http]

Most-used options:

• --path
• --no-upgrade
• --dry-run
• --check
• --show-diff
• --output human|json|both
• --json-report <file>
• --backup-keep-last <n> (default 5)
• --policy lower-bound|floor-only|floor-and-cap|update-in-place

Help discoverability:

reqsync help all
reqsync run --help
reqsync mcp --help

Common workflows

# quick local refresh
reqsync run --show-diff

# no network / no pip upgrade
reqsync run --no-upgrade --dry-run --show-diff

# machine output for tools/models
reqsync run --no-upgrade --dry-run --output json

# update constraints too
reqsync run --path requirements/base.txt --update-constraints

Output shape (for models/tools)

--output json or Python API returns structured keys:

• changed
• files (with role, changed, change_count)
• changes (file, package, installed_version, old_line, new_line)
• backup_paths
• diff

Safety model

• Blocks outside virtualenv unless --system-ok.
• Blocks hash-pinned files unless --allow-hashes.
• Optional dirty-repo guard via --allow-dirty.
• Lock + backup + atomic write for safer file operations.
• Timestamped backups are auto-pruned (keep latest 5 per file by default).

Docs

• Usage
• Configuration
• Integration
• Changelog

Author & Links

Created by: Roy Dawson IV
GitHub: https://github.com/imyourboyroy
PyPi: https://pypi.org/user/ImYourBoyRoy/

Project repo: https://github.com/ImYourBoyRoy/reqsync

License

MIT — see LICENSE.