Python build (build-py)

Summary

point build-py is the optional Python emit target. It lowers the same semantic .point source as point build, but writes .py files for hosts that run Python 3.12+.

Use it for logic, actions, routes, workflows, and commands — not for views, layouts, or client realtime code. Generated modules bootstrap packages/point/python_std/ (or the installed @hatchingpoint/point/python_std path) so use std.* resolves to in-package shims instead of ad-hoc pip dependencies.

Do not hand-edit generated/*.py. Repair .point and rebuild.

Project manifest target (optional)

Set a default emit target in point.json:

{
  "name": "my-automation",
  "version": "0.1.0",
  "emit": "python"
}

Then point build src/tools/runner.point writes Python (default generated/runner.py) instead of JavaScript. Per-module overrides use modules:

{
  "emit": "python",
  "modules": {
    "src/ui/app.point": { "emit": "javascript" }
  }
}

point build-py remains explicit when you want Python regardless of manifest settings.

Single-file build

point build-py examples/math.point generated/math.py
point build-py examples/action.point generated/action.py
point build-py examples/tools/process-runner.point generated/process-runner.py

build-py merges use dependencies before check and emit (same as build-py-all). A module that use std.process inlines or imports sibling generated std wrappers as needed.

Default output when omitted: generated/<base>.py.

Batch build

point build-py-all

Emits Python for every discovered pure-logic fixture plus actions, routes, workflows, and commands. Skips views, pages, and other unsupported block families. Root package.json exposes this as bun run build:py; CI runs it to keep generated/*.py in sync.

Run generated Python

Pure logic (no asyncio):

point build-py examples/math.point generated/math.py
python3 -c "import importlib.util, json; spec=importlib.util.spec_from_file_location('math','generated/math.py'); m=importlib.util.module_from_spec(spec); spec.loader.exec_module(m); print(json.dumps({'annual': m.annualPrice(10)}))"

Async action:

point build-py examples/action.point generated/action.py
python3 -c "import asyncio, importlib.util; spec=importlib.util.spec_from_file_location('action','generated/action.py'); m=importlib.util.module_from_spec(spec); spec.loader.exec_module(m); print(asyncio.run(m.loadConfigContents('examples/action.point')).startswith('module Actions'))"

Command entrypoint (if __name__ == "__main__"):

point build-py examples/command.point generated/command.py
python3 generated/command.py

Process + std bridge (use std.process):

point build-py examples/tools/process-runner.point generated/process-runner.py
python3 -c "import asyncio, importlib.util, json; spec=importlib.util.spec_from_file_location('runner','generated/process-runner.py'); m=importlib.util.module_from_spec(spec); spec.loader.exec_module(m); print(json.dumps(asyncio.run(m.processRunnerDemoResult('hello'))))"

Expected process-runner output shape: {"stdout": "hello\n", "stderr": "", "exitCode": 0} (platform echo may vary slightly).

HTTP routes (stdlib server):

point build-py examples/api/middleware-demo.point generated/middleware-demo.py
python3 -c "import importlib.util, os, sys; spec=importlib.util.spec_from_file_location('demo','generated/middleware-demo.py'); m=importlib.util.module_from_spec(spec); spec.loader.exec_module(m); os.environ.setdefault('PORT','8765'); m.start_routes_server()"

std bridge

Point import	Python emit
`use std.json`	`from point_std.json import …`
`use std.path`	`from point_std.path import …`
`use std.process`	`from point_std.process import processSpawn as …`
Relative `./process` (batch emit)	`from process import …` (sibling generated module)

See docs/python-emit-registry.md in the repository for the full external shim map.

Parity tests

bun run test:py-parity
bun test tests/python-parity-suite.test.ts tests/python-std-parity.test.ts

Compares JS and Python outputs for math, path-demo, std/json, std/crypto, std/yaml, process-runner, and middleware-demo when python3 is available.

Limits

Area	Status
Views / JSX / layouts	Not emitted
Realtime WebSocket client	JS/TS only
FastAPI	Not required — routes use stdlib `http.server`
`point.json` `"emit": "python"` per module	Project default or per-module override — `point build` emits `.py` when set