metal-cdn

PyPI: pymergetic-metal-cdn · Client: pymergetic-metal-cdn-client
Live demo: cdn.pymergetic.com/cdn · Pack format: wasmmod

Async FastAPI channel for signed wasmmod packs — browse, publish, inspect, and try them in a browser MicroPython shell.

Experimental. Data on the public demo is wiped often. Short tests only — not for production.

Channel state (artifacts + index.json) lives in object storage.
Publisher identity (users + ACL) lives in SQL.
Devices still verify pack signatures with wasmmod — this service does not replace that.

---

What you get

Surface	What it does
Browse	Package tree, lead / @version pins, dependents
Artifacts	Expand a .wasm / .zlib / AOT blob → pack file list
Source viewer	Highlighted text (py / c / rs / toml / …) or hex for binaries
µPy shell	In-browser MicroPython + wasmmod: ▶ → import + exports()
Sessions	Per-browser loader sessions — autoexec / pack / index hits
Publish	Multipart UI + CLI / thin client for CI

---

Inspect a pack

Click an artifact to open its guts — embedded Python (.py / .mpy / .pyc), natives, and optional wasmmod.source.

Text files open with syntax highlighting; bytecode and other binaries get a hex dump.

 

---

Install

pip install pymergetic-metal-cdn
# from this repo (client first — server depends on it):
pip install -e ./client -e ".[dev]" --config-settings editable_mode=compat

Thin publish/download wheel (no FastAPI): pymergetic-metal-cdn-client
→ pymergetic.metal.cdn_client — docs/CLIENT.md · client/README.md.

Version comes from git tags via setuptools-scm (metal-cdn --version).

---

Quick start

cd packages/metal-cdn
python3 -m venv .venv && source .venv/bin/activate
pip install -e ./client -e ".[dev]" --config-settings editable_mode=compat
cp .env.example .env
metal-cdn serve --reload
# → http://127.0.0.1:8000/cdn/        UI
# → http://127.0.0.1:8000/cdn/docs    OpenAPI

Docker one-shot

Rebuild browser µPy (if needed), sync REPL assets, docker build/run, seed sample packs:

./scripts/dev-up.sh
# → http://127.0.0.1:8000/cdn/   (µPy: packages() | import hello)

Flags: --no-upy, --no-seed, --seed-only.
Env: METALPYTHON, METAL_CDN_URL, METAL_CDN_PORT, METAL_CDN_SESSION_SECRET.

Public TLS edge

https://cdn.pymergetic.com/cdn/ — see docs/PROXY.md.

./scripts/dev-up.sh --no-upy
docker compose --profile proxy up -d nginx
curl -sf https://cdn.pymergetic.com/cdn/health

---

Try packs in the shell

The floating µPy panel warms MicroPython in the background. When status is ready, hit ▶ on an artifact (or type it yourself):

import hello
exports(hello)      # public names + types (+ docstring line when set)
hello.greet()

loaded hello · 5 public
  add (WasmFunc)
  hello (WasmFunc)
  greet (function)
  answer (function)
  util (module)

• packages() — live lead catalog (or autoexec snapshot)
• exports(mod) — shipped in autoexec (same place as help())
• GET /repl/autoexec.py mints/reuses a ShellSession, sets wasm.cdn + import hook + SESSION_ID
• Pack/index hits with the session cookie show up under Sessions
• Login claims prior anon sessions; Logout mints a fresh anon

▶ on a .wasm / .zlib / AOT row runs exactly import <pkg> then exports(<pkg>).

---

Client CLI

metal-cdn login --url http://127.0.0.1:8000/cdn --email you@example.com --register
metal-cdn claim hello
metal-cdn publish hello 0.1.0 ./hello.wasm ./hello.wasm.zlib
metal-cdn whoami

Web publish UI: {BASE_PATH}/publish after login.
One-shot pack→AOT→sign→zlib→upload: wasmmod.py publish (docs/CLIENT.md).
Releases / PyPI tags: docs/RELEASE.md.

Optional Postgres: docker compose up -d db + METAL_CDN_DATABASE_URL=….

---

Layout

client/pyproject.toml          # pymergetic-metal-cdn-client
pymergetic/metal/
  cdn_client/                  # thin HTTP client (shared sources)
  cdn/                         # FastAPI server + UI + REPL
screenshots/                   # UI stills for this README

from pymergetic.metal.cdn.main import create_app
from pymergetic.metal.cdn_client import CdnClient

API sketch

Method	Path	Role
GET	/health /ready /metrics	Liveness / readiness / Prometheus
POST	/auth/*	Register, login, token, API keys
GET	/api/sessions	Shell sessions for cookie principal
GET	/repl/autoexec.py	Browser µPy bootstrap
POST	/packages/{name}/claim	Claim ownership
GET	/index/lead	Device-facing index.json
GET	/packages/{name}/closure	Exact-deps install order
POST	/publish	Multipart publish
GET	/artifacts/…	Download / inspect / embedded files

metal-cdn db upgrade   # Alembic

Related

• docs/LAYOUT.md · docs/INDEX.md · docs/PROXY.md
• docs/CLIENT.md · docs/RELEASE.md · docs/ROADMAP.md
• Pack format: wasmmod PACK.md

License

MIT — Rouven Raudzus (raudzus@pymergetic.com)