read.markets/app/main.py
Giorgio Gilestro 6c13f855e9 polar: build /api/polar/webhook handler
Standalone router for inbound Polar (merchant-of-record) deliveries.
No bearer-token dep — authenticity comes from the Standard Webhooks
HMAC instead. Wired up so it's safe to deploy dark: empty
POLAR_WEBHOOK_SECRET makes the endpoint return 503 (loud) rather than
accept unsigned events.

Behaviour
- Standard Webhooks signature verification: HMAC-SHA256 over
  `{webhook-id}.{webhook-timestamp}.{body}`, base64 secret prefixed
  whsec_, ±5min replay window, constant-time compare against any of
  the space-separated v1 tokens.
- Idempotency via UNIQUE on polar_events.event_id — a replayed
  webhook-id short-circuits to 200 "duplicate" without re-running.
- Event dispatch table covers the 10 events we subscribed to:
  subscription.{created,active,updated,uncanceled} -> tier=paid +
  persist polar_customer_id / polar_subscription_id.
  subscription.revoked -> tier=free (customer id kept so a resub
  matches the same User row).
  canceled / past_due / order.* / refund.created -> audit only.
- Unknown event types are acked 200 + recorded; we don't want to 4xx
  on something Polar adds in the future and trigger their retry loop.

Schema (migration 0018)
- users.polar_customer_id, users.polar_subscription_id (both nullable
  String(64)); UNIQUE on polar_customer_id so two users can't claim
  the same Polar identity.
- polar_events table: event_id (unique), event_type, received_at,
  processed_at, error, raw payload (truncated to 16 KiB).

Tests
- 7 in tests/test_polar_webhook.py: bad signature -> 401, stale
  timestamp -> 401, missing headers -> 400, subscription.active flips
  tier to paid + stores IDs, subscription.revoked drops to free while
  keeping customer link, replayed webhook-id is no-op, unknown event
  is acked.
- Full suite: 212 passed, 5 skipped.

Operator next steps before saving the webhook in Polar
1. Pull this branch to prod and apply migration 0018.
2. Save the webhook in Polar pointing at
   https://read.markets/api/polar/webhook — Polar will accept the
   save even though our endpoint still 503s (no secret yet).
3. Copy the secret Polar reveals into the prod .env as
   POLAR_WEBHOOK_SECRET=whsec_... and restart the app.
4. Trigger a test event from Polar's dashboard to confirm 200 OK.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 17:42:41 +02:00

99 lines
3.8 KiB
Python

"""FastAPI entrypoint. Runs Alembic migrations on startup, bootstraps the
feeds table from TOML, mounts the API + HTML routers.
"""
from __future__ import annotations
import asyncio
from contextlib import asynccontextmanager
from pathlib import Path
from alembic import command
from alembic.config import Config as AlembicConfig
from fastapi import FastAPI
from fastapi.middleware.gzip import GZipMiddleware
from fastapi.staticfiles import StaticFiles
from app import branding
from app.config import get_settings
from app.db import get_session_factory
from app.logging import configure_logging, get_logger
from app.routers import api as api_router
from app.routers import auth as auth_router
from app.routers import email as email_router
from app.routers import pages as pages_router
from app.routers import polar_webhook as polar_webhook_router
from app.routers import public as public_router
from app.routers import sync as sync_router
from app.routers import universe as universe_router
from app.services.feeds_bootstrap import bootstrap_feeds
log = get_logger("cassandra")
APP_DIR = Path(__file__).resolve().parent
PROJECT_DIR = APP_DIR.parent
def _run_migrations() -> None:
"""Synchronous Alembic upgrade. Called once at lifespan startup."""
cfg = AlembicConfig(str(PROJECT_DIR / "alembic.ini"))
cfg.set_main_option("script_location", str(PROJECT_DIR / "alembic"))
cfg.set_main_option("sqlalchemy.url", get_settings().DATABASE_URL)
command.upgrade(cfg, "head")
@asynccontextmanager
async def lifespan(app: FastAPI):
configure_logging()
log.info("cassandra.startup")
s = get_settings()
if not s.PORTFOLIO_SYNC_PEPPER and not s.DATABASE_URL.startswith("sqlite"):
# Outer wrap still works (it just degrades to a per-user derived
# key with no shared secret), but a DB leak would let an attacker
# brute-force the PIN offline. Loud warning, not a hard failure.
log.warning("cassandra.portfolio_sync.pepper_missing")
try:
# Alembic's env.py uses asyncio.run() internally; offload it to a
# worker thread so it doesn't collide with FastAPI's running loop.
await asyncio.to_thread(_run_migrations)
log.info("cassandra.migrations.applied")
except Exception as e:
log.error("cassandra.migrations.failed", error=str(e))
raise
async with get_session_factory()() as session:
inserted = await bootstrap_feeds(session)
log.info("cassandra.feeds.bootstrap", inserted=inserted)
yield
log.info("cassandra.shutdown")
app = FastAPI(
title=branding.BRAND_NAME,
description="Macro-strategy dashboard",
version="0.1.0",
lifespan=lifespan,
)
# Gzip responses ≥500 bytes when the client sends Accept-Encoding: gzip.
# The Phase G universe payload is repetitive JSON that gzips to ~25-30%
# of raw size; compression is mandatory for that endpoint to be cheap.
app.add_middleware(GZipMiddleware, minimum_size=500)
app.mount(
"/static",
StaticFiles(directory=str(APP_DIR / "static")),
name="static",
)
app.include_router(auth_router.router, tags=["auth"])
app.include_router(email_router.router, tags=["email"])
app.include_router(api_router.router, prefix="/api", tags=["api"])
app.include_router(universe_router.router, prefix="/api", tags=["universe"])
app.include_router(sync_router.router, tags=["portfolio-sync"])
# Polar webhook (no bearer-token auth — authenticity via HMAC). Path
# `/api/polar/webhook` is set on the route itself so the URL Polar
# stores remains stable even if api_router's prefix ever moves.
app.include_router(polar_webhook_router.router, tags=["polar-webhook"])
# Public router (no auth dep) before pages_router so the marketing/legal
# paths can never collide with future authenticated routes.
app.include_router(public_router.router)
app.include_router(pages_router.router, tags=["pages"])