---
id: nab-index
version: "0.0.14"
license: MIT
license_treatment: permissive
maintenance: active
---

# nab-index — PyPI Simple-API client and on-disk cache for nab

License: permissive · Maintenance: active · Downloads: 425.5K/mo

## What it is and what it does

nab-index is a low-level PyPI Simple-API client library designed for tools that need typed, cached access to package metadata. It wraps the PyPI Simple API with an async transport layer (defaulting to urllib3, with optional httpx support), a disk cache for project listings and file metadata, and a multi-index router that can apply per-package index overrides using PEP 508 markers. It also includes a small VCS clone helper for higher-level VCS policy integration.

The package is primarily used internally by nab and nab-project; most end users should use nab instead. It targets developers building package management tools or dependency resolvers who need direct control over index queries and caching behavior. The API is explicitly marked as experimental and under rapid change, so adopters should pin to exact versions rather than using flexible version constraints.

Use it for:

- Building custom package management tools that need direct PyPI Simple-API access with on-disk caching.
- Implementing multi-index package resolution with per-package index overrides using PEP 508 markers.
- Integrating VCS-based package sources alongside PyPI indexes in a dependency resolver.
- Creating offline-capable package metadata queries by leveraging the disk cache layer.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

A typed PyPI Simple-API client with on-disk caching and multi-index routing, used internally by nab and nab-project to fetch and cache package metadata.

Yes, if you are building a package management tool or dependency resolver that needs typed PyPI Simple-API access with caching and multi-index routing. No, if you are an end user looking for package management—use nab instead. Condition: pin to an exact version because the API is under rapid experimentation. The package is actively maintained, has no known vulnerabilities, and carries a permissive MIT license.

## Install

pip install nab-index
uv add nab-index
poetry add nab-index

## Installing nab-index

Before you install: Low friction: pure Python wheel with five runtime dependencies (nab-provider, packaging, truststore, typing-extensions, urllib3). Active maintenance with a release on 2026-08-14 and last commit the same day.

License in practice: MIT license (permissive) places no restrictions on use, modification, or distribution.

Quickstart:

pip install nab-index

from nab_index import SimpleIndex
index = SimpleIndex()
# Use the index to query PyPI Simple API with caching

Requires Python 3.10 or later; the API is under rapid experimentation, so pinning to an exact version is recommended.

Verify before relying:

- Whether the experimental API surface has stabilized enough for production use despite the beta status and recommendation to pin exact versions.
- Performance characteristics of the on-disk cache under high-volume or concurrent access patterns.

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 425.5K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

pypi simple api client, package metadata cache, async pypi index, on-disk cache pypi, multi-index package router, pypi-client, package-metadata, caching

[View on SkillFed](https://skillfed.io/packages/nab-index) · [View on PyPI](https://pypi.org/project/nab-index/)