pypi-axi wraps the public PyPI JSON API in an agent-ergonomic CLI. It returns TOON output (~40% fewer tokens than JSON), minimal default schemas, pre-computed aggregates, and structured errors — so an agent can answer "what's the latest version of X", "what does X depend on", or "how popular is X by downloads" in a single call. Read-only, no authentication required.

Install

npm install -g pypi-axi

Or run without installing:

npx -y pypi-axi <command>

Usage

The examples below are snapshots of live PyPI output; versions, dates, and counts will drift as packages change.

view

$ pypi-axi view requests
package:
  name: requests
  version: 2.34.2
  summary: Python HTTP for Humans.
  author: Kenneth Reitz
  license: Apache-2.0
  requiresPython: >=3.10
  projectUrls:
    Documentation: "https://requests.readthedocs.io"
    Source: "https://github.com/psf/requests"
  releaseCount: 163
  latestUpload: 2026-05-14
  dependencyCount: 6

Pass --version <X> to inspect a specific release, or --full to print the complete summary instead of the ~800 char preview.

versions

$ pypi-axi versions requests --limit 5
count: 5 of 160 total
versions[5]{version,uploadDate,yanked}:
  2.34.2,2026-05-14,no
  2.34.1,2026-05-13,no
  2.34.0,2026-05-11,no
  2.34.0.dev1,2026-05-03,no
  2.33.1,2026-03-30,no

deps

$ pypi-axi deps flask
package: Flask
version: 3.1.3
count: 9
deps[9]:
  - dep: blinker
    spec: >=1.9.0
  - dep: click
    spec: >=8.1.3
  - dep: importlib-metadata
    spec: >=3.6.0
    marker: "python_version < \"3.10\""
  ...

Packages with no dependencies return a definitive 0 dependencies for <pkg> <version> result instead of an empty list.

downloads

$ pypi-axi downloads requests
downloads:
  package: requests
  lastDay: 47943472
  lastWeek: 428064895
  lastMonth: 1715479760

Packages pypistats has no data for yet return { status: "no download data available yet" } instead of an error.

search

PyPI has no public search API (the old XML-RPC search endpoint was retired), so search always returns an honest error instead of scraping the HTML search page:

$ pypi-axi search foo
error: PyPI has no public search API
code: VALIDATION_ERROR
help[1]: Use `pypi-axi view <package>` to inspect a known package

No arguments

Running pypi-axi with no arguments prints the tool identity and command hints. Inside a Python project (a directory with requirements.txt, pyproject.toml, or setup.py), it also shows the declared dependencies alongside their latest available version on PyPI:

$ pypi-axi
bin: ~/.local/bin/pypi-axi
description: Inspect PyPI packages — versions, summaries, dependencies, downloads — with token-efficient output
project:
  source: requirements.txt
  dependencyCount: 3
  dependencies[3]{name,declaredSpec,latestAvailable}:
    requests,==2.31.0,2.34.2
    flask,>=2.0,3.1.3
    numpy,any,2.5.1

Agent integration

pypi-axi follows the AXI principle of offering an opt-in session integration first, and an on-demand skill second.

Session hooks (ambient context):

pypi-axi setup hooks

Installs idempotent SessionStart hooks for Claude Code, Codex, and OpenCode so agents see pypi-axi guidance at the start of each session.

Agent Skill (on-demand):

npx skills add mstuart/pypi-axi --skill pypi-axi

You only need one of these — they complement each other when both are installed.

How it maps to the 10 AXI principles

| # | Principle | In pypi-axi | | --- | --- | --- | | 1 | Token-efficient output | TOON on stdout via axi-sdk-js | | 2 | Minimal default schemas | versions returns version, uploadDate, yanked | | 3 | Content truncation | summary preview with ... (truncated, N chars total) + --full | | 4 | Pre-computed aggregates | release counts, dependency counts, "N of M total" | | 5 | Definitive empty states | 0 dependencies for <pkg> <version>, "no download data available yet" | | 6 | Structured errors & exit codes | TOON errors; 0/1/2 exit codes; no prompts | | 7 | Ambient context | setup hooks + installable skill | | 8 | Content first | no-args shows the local project's declared dependencies | | 9 | Contextual disclosure | next-step help lines on truncated/erroring output | | 10 | Consistent help | pypi-axi <command> --help; fast --version path |

Development

npm install
npm test              # vitest, fetch mocked against captured fixtures + one live check
npm run build          # tsc -> dist
npm run build:skill     # regenerate skills/pypi-axi/SKILL.md from the CLI's own help text
npm run dev -- view requests   # run from source

License

MIT