Notification channels

Add an email, bot or webhook channel so Calends has somewhere to send automatic reminders.

The same reminder goes to every enabled channel. Under Settings → Notification channels, click Add channel, pick a type, fill in the fields and save. Each channel has its own name and Enabled toggle; its Test button sends a test message to that channel only, and works before you’ve saved.

Channel URLs and tokens are stored on the server and available to the signed-in app, but never sent to the public page. Full backups include them.

A ledger that has never set up channels but has a “notification email” from older versions uses that address as its only email channel.

1. Under Settings → Notification channels, click Add channel.
2. Choose a type, complete its fields below and click Test. This sends a real message.
3. Save after a successful test and leave the channel enabled.

Email

Field	Details
Email address	Where to send.

Email goes through Cloudflare Email Sending, which needs the EMAIL binding and a MAIL_FROM sender address at deploy time, on a domain verified in Cloudflare. If the server isn’t set up for it, sending fails with an error saying email isn’t configured; use another channel instead. Setup is in Cloudflare Workers + D1.

Docker deployments can’t send email.

Telegram

Field	Details
Bot Token	Create a bot with @BotFather to get a token like 123456:ABC….
Chat ID	Your user ID or a group ID. Send your bot a message first, then use @userinfobot to find your ID.

Messages use Telegram’s HTML formatting, up to 4000 characters.

Lark (Feishu)

Field	Details
Webhook URL	Group settings → Bots → Add custom bot; copy the https://open.feishu.cn/open-apis/bot/v2/hook/… address.
Signing secret	Optional. Required if the bot has signature verification on.

Sent as a message card with a button that opens the app.

DingTalk

Field	Details
Webhook URL	Group settings → Bots → Custom bot; copy the https://oapi.dingtalk.com/robot/send?access_token=… address.
Signing secret	Optional. Required if the bot’s security setting uses signing; starts with SEC.

If the bot’s security setting uses custom keywords instead, choose a word that always appears in reminders.

WeCom

Field	Details
Webhook URL	Group chat → Add group bot; copy the https://qyapi.weixin.qq.com/cgi-bin/webhook/send?key=… address.

Sent as a Markdown message, up to 4000 characters.

Bark

Field	Details
Device Key	Install Bark on your iPhone and copy the key from the app.
Server	Optional, for a self-hosted Bark server; https://api.day.app by default.

ntfy

Field	Details
Topic	Pick a name that’s hard to guess, and subscribe to the same topic in the ntfy app.
Server	Optional; https://ntfy.sh by default.
Access token	Optional, for self-hosted or protected servers; sent as Authorization: Bearer.

ServerChan

Field	Details
SendKey	SCT… for ServerChan Turbo, or sctp… for ServerChan³. Calends picks the right endpoint from the prefix.

Pushes to WeChat.

Discord

Field	Details
Webhook URL	Channel settings → Integrations → Webhooks; copy the https://discord.com/api/webhooks/… address.

Sent as an embed.

Slack

Field	Details
Webhook URL	Turn on Incoming Webhooks in a Slack app and copy the https://hooks.slack.com/services/… address.

Custom webhook

Field	Details
URL	Where reminders are sent.
Extra header	Optional, a single header as Name: value, e.g. Authorization: Bearer ….

Calends sends a POST with JSON:

{
  "subject": "Subscription reminder: …",
  "intro": "You're spending … a month on subscriptions, with N active.",
  "kind": "daily",
  "sections": [
    { "heading": "Upcoming charges", "rows": [{ "title": "…", "amount": "…", "sub": "…" }] }
  ],
  "text": "plain-text version",
  "markdown": "Markdown version",
  "url": "https://calends.example.com/admin"
}

kind is daily (daily reminder), monthly (monthly bill preview) or test. text and markdown are the fully formatted message, ready to forward elsewhere; sections is the structured data if you’d rather format it yourself.

When sending fails

• Click Test next to the channel; on failure you’ll see the error the service returned.
• Many bot APIs return HTTP 200 even on errors, so Calends checks the error code in the response body (errcode for DingTalk and WeCom, code for Lark and ServerChan, ok for Telegram) and shows the reason.
• If a required field is empty, you’re told which field the channel is missing.