lens-contract 0.2.0

The shared contract surface for the lens analyser family — manifest builder + FastAPI/CLI scaffolding every member exposes.

lens-contract

The shared contract surface for the lens analyser family. Every Python member exposes the same manifest, the same GET /health + GET /manifest routes, and the same serve / manifest CLI subcommands. This package is that common surface, so a contract change is one release here instead of an edit in every analyser.

It is infrastructure, not an analyser (role: library): it does not appear in the family table and is not auto-routable.

What it provides

Helper	Replaces the per-repo…
make_manifest(...)	_version() try/except + MANIFEST dict in manifest.py
add_contract_routes(app, MANIFEST)	hand-written GET /health + GET /manifest
make_app(MANIFEST, analyse)	the whole api.py for the path-only common case
upload_tempfile(content, filename)	the POST /analyse upload→tempfile→cleanup dance
run_contract_subcommands(...)	the serve (+--reload) + manifest dispatch in cli.py
add_cors(app, env_prefix=…)	per-repo CORS (one impl; env-driven; never * by default)
add_rate_limit(app, env_prefix=…)	per-repo slowapi setup (opt-in; needs lens-contract[ratelimit])

Making any member Electron/browser-ready

add_cors lets any member front a browser or Electron app via env vars, no code change:

• {PREFIX}_MODE=desktop → allow localhost / 127.0.0.1 / file:// origins (Electron)
• otherwise → allow {PREFIX}_ALLOWED_ORIGINS (comma-separated; defaults to the common dev ports)

add_rate_limit is opt-in via {PREFIX}_RATE_LIMIT_ENABLED=true (limit from {PREFIX}_RATE_LIMIT, e.g. 60/minute).

What it deliberately does not provide

Per the family principle share the contract, not forced abstraction: the analyse() business logic, the human-readable CLI output (rich), and the rich analyse-CLI flags stay in each repo. rich is not even a dependency here.

Usage

# manifest.py
from lens_contract import make_manifest
MANIFEST = make_manifest(
    name="name-analyser", accepts=["..."], produces="NameAnalysis",
    extensions=[".ext"], auto_routable=True,
)

# api.py — common case
from lens_contract import make_app
from name_analyser import NameAnalyser
app = make_app(MANIFEST, lambda path: NameAnalyser().analyse(path))

# cli.py
from lens_contract import run_contract_subcommands
def main():
    if run_contract_subcommands(MANIFEST, app_path="name_analyser.api:app",
                                default_port=8010, env_prefix="NAME_ANALYSER"):
        return
    ...  # bespoke analyse argparse + human output

Members needing extra /analyse form fields (e.g. --llm) build their own app with add_contract_routes + upload_tempfile — see conversation-analyser as the reference adopter.

Develop

uv venv && uv pip install -e '.[dev]'
uv run pytest