Merge pull request 'Feature/add or remove' (#7) from feature/add-or-remove into main

Reviewed-on: #7

README.md

@@ -3,20 +3,18 @@
 
 ## Overview
 
-`service-royalroad-chapters` is a FastAPI-based webserver that monitors Royalroad stories for new chapters and sends notifications data to `backend-api-internal`.
+`service-royalroad-chapters` is a FastAPI-based webserver that monitors RSS feeds for new entries and sends a notification to every subscribed user through `backend-api-internal`. It supports two feed types:
 
-## Features
+- **Royal Road**: new chapters of a story
+- **Gitea**: new releases of a repository on `gitea.com/gitea/`
 
-- **RSS Feed Monitoring**: Parses Royal Road RSS feeds to detect new chapter releases
-- **Automatic Updates**: Updates database with latest chapter numbers
-- **Retry Logic**: Built-in retry mechanisms for network failures with exponential backoff
-- **Prometheus Metrics**: Request counters and performance monitoring on port 9000
+Feeds are shared between users. A feed is stored once and polled once, and each user has their own subscription with an optional custom name.
 
 ## Prerequisites
 
-- Python 3.10+
-- MySQL database
-- Backend notification service (for sending push notifications)
+- Python 3.11+
+- MySQL database with the tables described under [Database](database.sql), including the `users` table
+- `backend-api-internal` (receives the notifications)
 - Royal Road story IDs
 
 ## Installation
@@ -25,6 +23,32 @@
 pip install -r requirements.txt
 ```
 
+Internal libraries (`lib-db-module`, `lib-secret-manager`, `lib-service-auth`) come from the Gitea package registry. Point pip at it first:
+
+```bash
+export PIP_EXTRA_INDEX_URL=https://git.gansejunge.com/api/packages/notifier/pypi/simple/
+```
+
+## Configuration
+
+Secrets are read from files under `/etc/secrets/` (Kubernetes secrets) and fall back to environment variables for development. The files are deleted after startup.
+
+| Secret | File | Dev environment variable |
+|---|---|---|
+| Gateway key | `/etc/secrets/gateway_key` | `GATEWAY_KEY` |
+| Scheduler key | `/etc/secrets/scheduler_key` | `SCHEDULER_KEY` |
+| Gitea token | `/etc/secrets/gitea_token` | `GITEA_TOKEN` |
+| Notification API key | `/etc/secrets/api_key` | (see `lib-secret-manager`) |
+| Database user | `/etc/secrets/db_username` | (see `lib-db-module`) |
+| Database password | `/etc/secrets/db_password` | (see `lib-db-module`) |
+
+Caller keys must be at least 32 characters and must differ from each other. Generate them with:
+
+```bash
+python3 -c "import secrets; print(secrets.token_urlsafe(32))"
+```
+
+
 ## Running the Service
 
 ```bash
@@ -35,36 +59,162 @@ This starts two servers:
 - **Main API**: `http://0.0.0.0:5000` - Handles chapter check requests
 - **Metrics Server**: `http://0.0.0.0:9000/metrics` - Prometheus metrics endpoint
 
-### API Endpoint
+## Authentication
 
-#### Check for New Chapters
+Every route on the main API requires a bearer key, and each key belongs to exactly one caller:
 
 ```http
-GET /royalroad
+Authorization: Bearer <key>
 ```
 
-**Response:**
+| Caller | Key | May call |
+|---|---|---|
+| Gateway (`backend-api`) | `gateway_key` | `/add/feed`, `/delete/feed` |
+| Scheduler (CronJob) | `scheduler_key` | `/royalroad`, `/gitea` |
+
+A missing or unknown key returns `401`. A valid key used on a route it is not allowed to call returns `403`.
+
+User routes also require the user the gateway is acting for:
+
+```http
+X-User-Id: 1
+```
+
+The value must be a positive integer.
+
+## API
+
+### Subscribe to a feed
+
+```http
+POST /add/feed
+```
+
+**Headers:** `Authorization: Bearer <gateway_key>`, `X-User-Id: <user id>`
+
+**Body:**
+
 ```json
 {
-  "status": "checked"
+	"type": "royalroad",
+	"rss_feed_url": "royalroad.com/fiction/118891",
+	"custom_name": "My favourite story"
+}
+```
+
+| Field | Required | Description |
+|---|---|---|
+| `type` | yes | `royalroad` or `gitea` |
+| `rss_feed_url` | yes | Feed or page URL, see [Accepted feed URLs](#accepted-feed-urls) |
+| `custom_name` | no | Name used as the notification title. If empty, the title from the feed is used |
+
+**Response:**
+
+```json
+{
+	"status": "ok",
+	"detail": "Subscribed to feed",
+	"feed_url": "https://www.royalroad.com/fiction/syndication/65058"
 }
 ```
 
 **Behavior:**
-1. Fetches all active stories from the database
-2. Queries Royal Road RSS feed for each story
-3. Compares latest chapter with stored chapter number
-4. Updates database if new chapter is detected
-5. Sends notification to backend service
 
-**Error Responses:**
-- `404`: Feed not found or has no entries
-- `500`: Internal server error during processing
-- `503`: Notification service unavailable after retries
+1. Validates the URL and converts it to the canonical feed URL
+2. If the feed is not stored yet, checks that it exists and records its latest entry, so only entries published after subscribing trigger a notification
+3. Stores the feed, or reactivates it if it was inactive
+4. Creates the user's subscription
+
+Sending the same request again renames the subscription and reactivates it if the user had unsubscribed.
+
+### Unsubscribe from a feed
+
+```http
+POST /delete/feed
+```
+
+**Headers:** `Authorization: Bearer <gateway_key>`, `X-User-Id: <user id>`
+
+**Body:** same as `/add/feed`. `custom_name` is ignored.
+
+**Response:**
+
+```json
+{
+	"status": "ok",
+	"detail": "Unsubscribed from feed",
+	"feed_url": "https://www.royalroad.com/fiction/syndication/118891"
+}
+```
+
+**Behavior:** deactivates the user's subscription. If no active subscribers are left, the feed itself is deactivated and is no longer polled. An unknown feed also returns `ok`.
+
+### Check for new chapters
+
+```http
+POST /royalroad
+```
+
+**Headers:** `Authorization: Bearer <scheduler_key>`
+
+### Check for new Gitea releases
+
+```http
+POST /gitea
+```
+
+**Headers:** `Authorization: Bearer <scheduler_key>`
+
+**Response (both):**
+
+```json
+{
+	"checked": 12,
+	"new": 2,
+	"errors": 0
+}
+```
+
+If any feed failed, the same counts are returned as the `detail` of a `500` response.
+
+**Notification failures:**
+
+- If every notification for a feed fails, `last_entry` is not updated, the feed counts as an error and it is retried on the next run
+- If only some fail, `last_entry` is updated, so the users who were notified are not notified again
+- If the notification backend is unavailable, the remaining users of that feed are skipped
+
+When a new release of `gitea/runner` is detected, the service also triggers the runner build workflow on the Gitea instance, using `gitea_token`.
+
+## Accepted feed URLs
+
+The scheme and `www.` are optional. Whatever is submitted is converted to the canonical feed URL.
+
+| Type | Accepted input | Stored as |
+|---|---|---|
+| `royalroad` | `royalroad.com/fiction/118891`<br>`https://www.royalroad.com/fiction/118891/story-title` | `https://www.royalroad.com/fiction/syndication/118891` |
+| `gitea` | `gitea.com/gitea/runner`<br>`https://gitea.com/gitea/runner/releases`<br>`https://gitea.com/gitea/runner/releases.rss` | `https://gitea.com/gitea/runner/releases.rss` |
+
+Only repositories under `gitea.com/gitea/` are supported.
+
+## Error Responses
+
+Errors are returned as `{"detail": "<message>"}`.
+
+| Status | Cause | Example `detail` |
+|---|---|---|
+| `401` | Missing or invalid bearer key | `Unauthorized` |
+| `403` | Key is valid but not allowed on this route | `Forbidden` |
+| `422` | Invalid `X-User-Id` or body | `type: Input should be 'royalroad' or 'gitea'` |
+| `422` | URL does not match the feed type | `A gitea feed must be on gitea.com` |
+| `422` | URL has the wrong path | `Unrecognised feed path (expected e.g. royalroad.com/fiction/118891)` |
+| `422` | The feed does not exist | `The feed does not exist: <url>` |
+| `502` | The feed could not be checked right now | `Could not verify the feed right now, try again later: <url>` |
+| `500` | Internal error, or a check run with failed feeds | |
+
 
 ## Notification Format
 
-Messages sent to the backend service:
+One message is sent to `backend-api-internal` per subscriber:
 
 ```json
 {
@@ -79,11 +229,7 @@ Messages sent to the backend service:
 }
 ```
 
-**Headers:**
-```http
-X-API-Key-Internal: <api_key>
-Content-Type: application/json
-```
+Gitea releases use the category `utility`. When a subscription has no custom name, the title is the feed title for Royal Road and the repository path (for example `gitea.com/gitea/runner`) for Gitea.
 
 ## Monitoring
 

requirements.txt

@@ -10,11 +10,11 @@ feedparser==6.0.14
 feedparser-sgmllib==2.1.0
 h11==0.16.0
 idna==3.20
-lib-db-module==0.3.0
+lib-db-module==0.4.0
 lib-secret-manager==0.3.1
 lib-send-notifications==0.1.0
 lib-service-auth==0.1.0
-mysql-connector-python==9.4.0
+mysql-connector-python==26.10.0
 opentelemetry-api==1.45.1
 prometheus_client==0.26.0
 pydantic==2.14.1

src/feed_errors.py

@@ -0,0 +1,35 @@
+class FeedError(Exception):
+	"""Base class for every feed problem the API can explain to a client."""
+	status_code = 400
+
+
+class InvalidFeedUrlError(FeedError, ValueError):
+	"""The URL is malformed or doesn't fit the chosen feed type.
+
+	Subclasses ValueError so Pydantic reports it as a normal 422 validation error.
+	"""
+	status_code = 422
+
+
+class WrongHostError(InvalidFeedUrlError):
+	def __init__(self, feed_type: str, expected_host: str):
+		super().__init__(f"A {feed_type} feed must be on {expected_host}")
+
+
+class UnsupportedPathError(InvalidFeedUrlError):
+	def __init__(self, hint: str):
+		super().__init__(f"Unrecognised feed path ({hint})")
+
+
+class FeedNotFoundError(FeedError):
+	status_code = 422
+
+	def __init__(self, url: str):
+		super().__init__(f"The feed does not exist: {url}")
+
+
+class FeedCheckFailedError(FeedError):
+	status_code = 502
+
+	def __init__(self, url: str):
+		super().__init__(f"Could not verify the feed right now, try again later: {url}")

src/feed_handler.py

@@ -1,11 +1,11 @@
 import time
-from dataclasses import dataclass
-from typing import Tuple
+from typing import assert_never
 
 import feedparser
 import requests
-from pydantic import BaseModel
 
+from feed_errors import FeedCheckFailedError, FeedNotFoundError
+from models import FeedEntryType, FeedUpdate
 from simple_logger_handler import setup_logger
 
 logger = setup_logger(__name__)
@@ -14,14 +14,6 @@ _GITEA_INSTANCE_BASE_URL="https://git.gansejunge.com"
 _GITEA_REPOSITORY_OWNER="utility"
 
 
-@dataclass(frozen=True)
-class RoyalRoadStory(BaseModel):
-	chapter_title: str
-	link: str
-	story_title: str
-	chapter_id: str
-
-
 def get_rss_feed_data(rss_feed_url: str, max_retries: int = 3) -> feedparser.FeedParserDict:
 	"""
 	Fetches information from any RSS feed, with retries on network-related errors.
@@ -62,26 +54,28 @@ def get_rss_feed_data(rss_feed_url: str, max_retries: int = 3) -> feedparser.Fee
 	logger.debug(f"[Feed] Parsed {len(feed.entries)} entries from {rss_feed_url}")
 	return feed
 
-def grab_gitea_release_information(rss_feed_url: str) -> Tuple[str, str]:
+def grab_gitea_release_information(rss_feed_url: str) -> FeedUpdate:
 	"""
 	Fetches the latest release information from a Gitea releases RSS feed.
 
 	Returns:
-		A tuple: (release_title, release_link)
+		FeedUpdate:
 
 	Raises:
 		ValueError: If the feed has no entries.
 	"""
 	feed = get_rss_feed_data(rss_feed_url)
-	entry = feed.entries[0]
-	title = entry["title"]
-	link = entry["link"]
+	feed_update = FeedUpdate (
+		entry_id = feed.entries[0]["link"],
+		feed_title = feed.feed.title,
+		body_title = feed.entries[0]["title"],
+		link = feed.entries[0]["link"],
+	)
+	logger.info(f"[Feed] Latest release for feed '{rss_feed_url}': {feed_update.feed_title}")
+	logger.debug(f"[Feed] Latest release for feed '{rss_feed_url}': {feed_update.feed_title} -> {feed_update.link}")
+	return feed_update
 
-	logger.info(f"[Feed] Latest release for feed '{rss_feed_url}': {title}")
-	logger.debug(f"[Feed] Latest release for feed '{rss_feed_url}': {title} -> {link}")
-	return title, link
-
-def grab_royal_road_chapter_information(rss_feed_url: str) -> RoyalRoadStory :
+def grab_royal_road_chapter_information(rss_feed_url: str) -> FeedUpdate :
 	"""
 	Fetches the latest chapter information from a Royalroad RSS feed.
 
@@ -89,7 +83,7 @@ def grab_royal_road_chapter_information(rss_feed_url: str) -> RoyalRoadStory :
 		rss_feed_url: URL of the Royalroad story's RSS feed.
 
 	Returns:
-		A tuple: (chapter_title, chapter_link, story_title, chapter_id)
+		FeedUpdate
 
 	Raises:
 		ValueError: If the feed has no entries.
@@ -97,19 +91,19 @@ def grab_royal_road_chapter_information(rss_feed_url: str) -> RoyalRoadStory :
 	feed = get_rss_feed_data(rss_feed_url)
 	latest_chapter_data = feed.entries[0]
 	chapter_title_with_story_title = latest_chapter_data["title"]
-	chapter_title = chapter_title_with_story_title.removeprefix(feed.feed.title).removeprefix(" - ")
+	body_title = chapter_title_with_story_title.removeprefix(feed.feed.title).removeprefix(" - ")
 
-	royal_road_story =  RoyalRoadStory (
-		chapter_title = chapter_title,
+	feed_update =  FeedUpdate (
+		entry_id = str(latest_chapter_data["id"]),
+		feed_title = feed.feed.title,
+		body_title = body_title,
 		link = latest_chapter_data["link"],
-		story_title = feed.feed.title,
-		chapter_id = str(latest_chapter_data["id"])
 	)
 
-	logger.info(f"[Feed] Latest chapter for story '{royal_road_story.story_title}': {royal_road_story.chapter_title}")
-	logger.debug(f"[Feed] Latest chapter for story '{royal_road_story.story_title}' (RSS URL {rss_feed_url}):"
-				f"{royal_road_story.chapter_title} (ID {royal_road_story.chapter_id}) -> {royal_road_story.link}")
-	return royal_road_story
+	logger.info(f"[Feed] Latest chapter for story '{feed_update.feed_title}': {feed_update.body_title}")
+	logger.debug(f"[Feed] Latest chapter for story '{feed_update.feed_title}' (RSS URL {rss_feed_url}):"
+				f"{feed_update.body_title} (ID {feed_update.entry_id}) -> {feed_update.link}")
+	return feed_update
 
 def build_gitea_runner(version: str, gitea_token: str) -> bool:
 	url = (
@@ -122,7 +116,7 @@ def build_gitea_runner(version: str, gitea_token: str) -> bool:
 	payload = {
 		"ref": "main",
 		"inputs": {
-			"version": version.lstrip("v"),
+			"version": version.removeprefix("v"),
 			"revision": "1",
 		},
 	}
@@ -138,10 +132,30 @@ def build_gitea_runner(version: str, gitea_token: str) -> bool:
 		logger.warning(f"[Feed] Failed to run Gitea-Runner build: {e}")
 	return False
 
+def ensure_feed_exists(url: str, timeout: tuple[float, float] = (3.0, 5.0)) -> None:
+	try:
+		with requests.get(url, stream=True, timeout=timeout, allow_redirects=False) as response:
+			status = response.status_code
+	except requests.RequestException as e:
+		raise FeedCheckFailedError(url) from e
+	if status == 404:
+		raise FeedNotFoundError(url)
+	if status != 200:
+		raise FeedCheckFailedError(url)
+
+def fetch_latest(feed_type: FeedEntryType, url: str) -> FeedUpdate:
+	match feed_type:
+		case FeedEntryType.ROYALROAD:
+			return grab_royal_road_chapter_information(url)
+		case FeedEntryType.GITEA:
+			return grab_gitea_release_information(url)
+		case _:
+			assert_never(feed_type)
+
 if __name__ == "__main__":
-	#rsssss="https://gitea.com/gitea/runner/releases.rss"
+	rsssss="https://gitea.com/gitea/runner/releases.rss"
 	#print(get_rss_feed_data(rsssss))
-	#print(grab_gitea_release_information(rsssss))
+	print(grab_gitea_release_information(rsssss))
 	id="118891"
 	rss_feed_url = f"https://www.royalroad.com/fiction/syndication/{id}"
 	print(grab_royal_road_chapter_information(rss_feed_url))

src/main.py

@@ -4,22 +4,29 @@ from contextlib import asynccontextmanager
 
 import uvicorn
 from fastapi import APIRouter, Depends, FastAPI, HTTPException, Request
+from fastapi.exceptions import RequestValidationError
+from fastapi.responses import JSONResponse
+from requests.exceptions import RequestException
 
 from auth_config import Caller, auth
 from db_module import close_connection_pool, create_connection_pool, get_db, start_healthcheck_thread
+from feed_errors import FeedCheckFailedError, FeedError
 from feed_handler import (
 	build_gitea_runner,
+	ensure_feed_exists,
+	fetch_latest,
 	grab_gitea_release_information,
 	grab_royal_road_chapter_information,
 )
 from metrics_server import REQUEST_COUNTER, metrics_api
+from models import FeedEntry
 from secret_manager import cleanup_secret_files, get_secret
 from send_notifications import NotificationClient, NotificationError, NotificationUnavailableError
+from service_auth import UserId
 from simple_logger_handler import LOG_LEVEL, setup_logger
 
 logger = setup_logger(__name__)
 
-
 @asynccontextmanager
 async def lifespan(app: FastAPI):
 	logger.info("[FastAPI] Starting application...")
@@ -53,6 +60,31 @@ api = FastAPI(
 		dependencies=[Depends(auth.authenticate)],
 )
 
+@api.exception_handler(FeedError)
+async def feed_error_handler(request: Request, exc: FeedError):
+	return JSONResponse(status_code=exc.status_code, content={"detail":str(exc)})
+
+@api.exception_handler(RequestValidationError)
+async def validation_error_handler(request: Request, exc: RequestValidationError):
+	errors = exc.errors()
+
+	# 1) If one of our own FeedErrors caused it, use its message as is
+	for err in errors:
+		original = (err.get("ctx") or {}).get("error")
+		if isinstance(original, FeedError):
+			return JSONResponse(
+				status_code=original.status_code,
+				content={"detail": str(original)},
+			)
+
+	# 2) Anything else (missing field, bad enum value, bad header): flatten to one string
+	messages = []
+	for err in errors:
+		field = ".".join(str(p) for p in err["loc"] if p != "body")
+		msg = err["msg"].removeprefix("Value error, ")
+		messages.append(f"{field}: {msg}" if field else msg)
+	return JSONResponse(status_code=422, content={"detail": "; ".join(messages)})
+
 @api.middleware("http")
 async def prometheus_middleware(request: Request, call_next):
 	logger.debug(f"[FastAPI] Incoming request: {request.method} {request.url.path}")
@@ -103,13 +135,13 @@ def get_release_information(request: Request, db = Depends(get_db)):
 	for feed_id, rss_feed, last_entry in feeds:
 		results["checked"] += 1
 		try:
-			release_title, link = grab_gitea_release_information(rss_feed)
-			logger.debug(f"[FastAPI] ID:{feed_id},RSS Feed {rss_feed}: db={last_entry}, online={link}")
+			gitea_release_information = grab_gitea_release_information(rss_feed)
+			logger.debug(f"[FastAPI] ID:{feed_id},RSS Feed {rss_feed}: db={last_entry}, online={gitea_release_information.entry_id}")
 
-			if link == last_entry:
+			if gitea_release_information.entry_id == last_entry:
 				continue
 
-			logger.info(f"[FastAPI] Release change for ID {feed_id}: {release_title}")
+			logger.info(f"[FastAPI] Release change for ID {feed_id}: {gitea_release_information.body_title}")
 
 			with db.cursor() as cursor:
 				cursor.execute(
@@ -122,13 +154,13 @@ def get_release_information(request: Request, db = Depends(get_db)):
 
 			sent = 0
 			failed = 0
+			repo = gitea_release_information.link.split("/releases")[0].removeprefix("https://")
 			for user_id,feed_name in subscribers:
 				try:
-					repo = link.split("/releases")[0].removeprefix("https://")
 					request.app.state.notifier.send(
 						title=feed_name or repo,
-						body=release_title,
-						link=link,
+						body=gitea_release_information.body_title,
+						link=gitea_release_information.link,
 						category="utility",
 						user_id=user_id,
 					)
@@ -149,14 +181,14 @@ def get_release_information(request: Request, db = Depends(get_db)):
 			with db.cursor() as cursor:
 				cursor.execute(
 					"UPDATE rss_feeds SET last_entry = %s WHERE id = %s",
-					(link, feed_id),
+					(gitea_release_information.entry_id, feed_id),
 				)
 			db.commit()
 			logger.debug(f"[FastAPI] Notification sent and database updated for Gitea feed ID {feed_id}")
 			results["new"] += 1
 
-			if link.startswith("https://gitea.com/gitea/runner/releases/tag/v"):
-				gitea_build_success = build_gitea_runner(release_title, request.app.state.gitea_token)
+			if gitea_release_information.link.startswith("https://gitea.com/gitea/runner/releases/tag/v"):
+				gitea_build_success = build_gitea_runner(gitea_release_information.body_title, request.app.state.gitea_token)
 				logger.info(f"[FastAPI] Gitea build ran successfully:{gitea_build_success}")
 
 		except Exception as e:
@@ -205,12 +237,12 @@ def get_chapters(request: Request, db = Depends(get_db)):
 		results["checked"] += 1
 		try:
 			story = grab_royal_road_chapter_information(rss_feed)
-			logger.debug(f"[FastAPI] ID:{feed_id},RSS Feed {rss_feed}: db={last_entry}, online={story.chapter_id}")
+			logger.debug(f"[FastAPI] ID:{feed_id},RSS Feed {rss_feed}: db={last_entry}, online={story.entry_id}")
 
-			if story.chapter_id == last_entry:
+			if story.entry_id == last_entry:
 				continue
 
-			logger.info(f"[FastAPI] New chapter detected for story ID {feed_id}: {story.story_title}")
+			logger.info(f"[FastAPI] New chapter detected for story ID {feed_id}: {story.feed_title}")
 			with db.cursor() as cursor:
 				cursor.execute (
 					"SELECT user_id, feed_name "
@@ -225,8 +257,8 @@ def get_chapters(request: Request, db = Depends(get_db)):
 			for user_id, feed_name in subscribers:
 				try:
 					request.app.state.notifier.send(
-						title=feed_name or story.story_title,
-						body=story.chapter_title,
+						title=feed_name or story.feed_title,
+						body=story.body_title,
 						link=story.link,
 						category="royal-road",
 						user_id=user_id,
@@ -235,11 +267,11 @@ def get_chapters(request: Request, db = Depends(get_db)):
 				except NotificationUnavailableError:
 					failed = len(subscribers) - sent
 					logger.error (f"[FastAPI] Notifications backend unavailable, skipping "
-								f"{failed} remaining user(s) for story={story.story_title}")
+								f"{failed} remaining user(s) for story={story.feed_title}")
 					break
 				except NotificationError as e:
 					failed += 1
-					logger.error(f"[FastAPI] Failed to send notification to user_id={user_id} for story={story.story_title} "
+					logger.error(f"[FastAPI] Failed to send notification to user_id={user_id} for story={story.feed_title} "
 								f"status={getattr(e, 'status_code',None)}")
 			if subscribers and sent == 0:
 				results["errors"] += 1
@@ -248,7 +280,7 @@ def get_chapters(request: Request, db = Depends(get_db)):
 			with db.cursor() as cursor:
 				cursor.execute(
 					"UPDATE rss_feeds SET last_entry = %s WHERE id = %s",
-					(story.chapter_id, feed_id),
+					(story.entry_id, feed_id),
 				)
 			db.commit()
 			logger.debug(f"[FastAPI] Notification sent and database updated for story ID {feed_id}")
@@ -269,6 +301,97 @@ def get_chapters(request: Request, db = Depends(get_db)):
 	logger.info(f"[FastAPI] Royalroad check complete: {results}")
 	return results
 
+@user_router.post("/add/feed")
+def add_feed(
+	user_id: UserId,
+	feed_entry: FeedEntry,
+	db = Depends(get_db)
+	):
+	url = feed_entry.rss_feed_url
+	logger.info(f"[FastAPI] Subscribe request: RSS URL={url}, user_id={user_id}")
+
+	with db.cursor() as cursor:
+		cursor.execute("SELECT id FROM rss_feeds WHERE rss_feed = %s", (url,),)
+		known = cursor.fetchone()
+
+	last_entry_id = None
+	if known is None:
+		ensure_feed_exists(url)
+		logger.info(f"[FastApi] Adding new RSS feed, type={feed_entry.type}, rss_feed_url={url}")
+		try:
+			last_entry_id = fetch_latest(feed_entry.type, url).entry_id
+		except (ValueError, RequestException) as e:
+			logger.warning(f"[FastAPI] Could not read latest entry for {url}, storing none")
+			raise FeedCheckFailedError(url) from e
+	try:
+		with db.cursor() as cursor:
+			cursor.execute(
+				"INSERT into rss_feeds (type,rss_feed,last_entry) VALUES (%s,%s,%s) "
+				"ON DUPLICATE KEY UPDATE id = LAST_INSERT_ID(id), active = 1",
+				(feed_entry.type, url, last_entry_id),
+			)
+			feed_id = cursor.lastrowid
+
+			cursor.execute (
+				"INSERT INTO rss_feed_subscriptions (user_id, rss_feed_id, feed_name) "
+				"VALUES (%s, %s, %s) "
+				"ON DUPLICATE KEY UPDATE active = 1, feed_name = VALUES(feed_name)",
+				(user_id, feed_id, feed_entry.custom_name),
+			)
+		db.commit()
+	except Exception as e:
+		db.rollback()
+		logger.exception(f"[FastAPI] Failed to subscribe user_id={user_id} to {url}")
+		raise HTTPException(status_code=500) from e
+			
+	logger.info(f"[FastAPI] user_id={user_id} subscribed to feed_id={feed_id}, url={url}")
+	return {"status":"ok","detail":"Subscribed to feed","feed_url":url}
+
+@user_router.post("/delete/feed")
+def delete_feed(
+	user_id: UserId,
+	feed_entry: FeedEntry,
+	db = Depends(get_db),
+	):
+	url = feed_entry.rss_feed_url
+	logger.info(f"[FastAPI] Unsubscribe request: RSS URL={url}, user_id={user_id}")
+
+	try:
+		with db.cursor() as cursor:
+			cursor.execute(
+				"SELECT id FROM rss_feeds WHERE rss_feed = %s",
+				(url,),
+			)
+			known = cursor.fetchone()
+
+			if known is None:
+				db.rollback()
+				return {"status":"ok","detail":"Unsubscribed to feed","feed_url":url}
+
+			feed_id = known[0]
+			cursor.execute(
+				"UPDATE rss_feed_subscriptions SET active = 0 "
+				"WHERE user_id = %s AND rss_feed_id = %s",
+				(user_id, feed_id),
+			)
+
+			cursor.execute(
+				"SELECT 1 from rss_feed_subscriptions "
+				"WHERE rss_feed_id = %s AND active = 1 LIMIT 1",
+				(feed_id,),
+			)
+			if cursor.fetchone() is None:
+				cursor.execute(
+					"UPDATE rss_feeds SET active = 0 WHERE id = %s",
+					(feed_id,),
+				)
+
+		db.commit()
+	except Exception as e:
+		db.rollback()
+		logger.exception(f"[FastAPI] Failed to unsubscribe user_id={user_id} to {url}")
+		raise HTTPException(status_code=500) from e
+	return {"status":"ok","detail":"Unsubscribed to feed","feed_url":url}
 api.include_router(user_router)
 api.include_router(scheduler_router)
 

src/models.py

@@ -0,0 +1,82 @@
+from dataclasses import dataclass
+from enum import StrEnum
+from typing import Self
+from urllib.parse import urlsplit
+
+from pydantic import BaseModel, Field, field_validator, model_validator
+
+from feed_errors import InvalidFeedUrlError, UnsupportedPathError, WrongHostError
+
+REPO_CHARS = frozenset("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.-")
+
+@dataclass(frozen=True)
+class FeedUpdate():
+	entry_id: str
+	feed_title: str
+	body_title: str
+	link: str | None = None
+
+class FeedEntryType(StrEnum):
+	ROYALROAD = "royalroad"
+	GITEA = "gitea"
+
+
+def _path_segments(raw: str, feed_type: FeedEntryType, host: str) -> list[str]:
+	"""Check scheme and host, then return the non-empty path segments."""
+	raw = raw.strip()
+	if "://" not in raw:
+		raw = "https://" + raw  # allow "royalroad.com/fiction/118891"
+	try:
+		parts = urlsplit(raw)
+	except ValueError as e:
+		raise InvalidFeedUrlError("The URL could not be parsed") from e
+	if parts.scheme not in ("http", "https"):
+		raise InvalidFeedUrlError("The URL must use http or https")
+	# Comparing the whole netloc also rejects ports and user@host
+	if parts.netloc.lower().removeprefix("www.") != host:
+		raise WrongHostError(feed_type.value, host)
+	return [s for s in parts.path.split("/") if s]
+
+
+def _royalroad_feed(segments: list[str]) -> str:
+	# fiction/<id>[/<slug>]
+	if len(segments) >= 2 and segments[0] == "fiction":
+		story_id = segments[1]
+		if story_id.isascii() and story_id.isdigit():
+			return f"https://www.royalroad.com/fiction/syndication/{int(story_id)}"
+	raise UnsupportedPathError("expected e.g. royalroad.com/fiction/118891")
+
+
+def _gitea_feed(segments: list[str]) -> str:
+	# gitea/<repo>[/releases | /releases.rss]
+	if len(segments) >= 2 and segments[0] == "gitea":
+		repo, rest = segments[1], segments[2:]
+		repo_ok = repo[0] not in ".-" and set(repo) <= REPO_CHARS
+		if repo_ok and rest in ([], ["releases"], ["releases.rss"]):
+			return f"https://gitea.com/gitea/{repo}/releases.rss"
+	raise UnsupportedPathError("expected e.g. gitea.com/gitea/runner")
+
+
+# To support a new feed type: add an enum member, a function above, add a case tofetch_latest and a line here.
+_RULES = {
+	FeedEntryType.ROYALROAD: ("royalroad.com", _royalroad_feed),
+	FeedEntryType.GITEA: ("gitea.com", _gitea_feed),
+}
+
+
+class FeedEntry(BaseModel):
+	type: FeedEntryType
+	rss_feed_url: str = Field(max_length=512)
+	custom_name: str | None = Field(default=None, max_length=255)
+
+	@field_validator("custom_name")
+	@classmethod
+	def blank_name_is_none(cls, v: str | None) -> str | None:
+		return (v or "").strip() or None
+
+	@model_validator(mode="after")
+	def normalise_feed_url(self) -> Self:
+		host, build_feed_url = _RULES[self.type]
+		segments = _path_segments(self.rss_feed_url, self.type, host)
+		self.rss_feed_url = build_feed_url(segments)
+		return self