ntfy vs SuprSend

ntfy

Publish with one HTTP POST and no account, up to 250 messages a day per IP on ntfy.sh. Unreserved topics on ntfy.sh can be read and written by anyone who knows the name.

SuprSend

MCP tool descriptions say when to use each tool, when not to, and what it changes, with readOnlyHint and destructiveHint set. No rate-limit page or 429 guidance.

ntfy

1. Use a long random topic name, or a reserved topic with a Bearer token
2. Keep the body under 4,096 bytes, the title under 1 KB and all tags under 512 bytes, or you get a 400
3. Don't blind-retry a publish. There's no idempotency key, so the person gets it twice
4. Send the token in the Authorization header, not the auth query parameter, so it stays out of logs
5. Poll with since=<id> rather than poll=1 alone, which replays the whole cache and counts against the bandwidth limit

SuprSend

1. Pass an idempotency key on each trigger. It holds for 24 hours
2. Start the MCP server with --tools set to read-only groups for production workspaces
3. Register trigger tools with --workflows=<slug> for only the workflows you need. The default registers none
4. Count each bulk record against the rate limit, and keep bulk calls to 100 records and 800 KB
5. Treat management API responses as secrets. They include the workspace secret in plain text