Tags

Tags are { name, value } pairs attached to an email. They are stored with the email, returned by GET /emails/{id} and echoed in every webhook payload for that email (as an object, "tags": { "category": "welcome" }). Use them to tie events back to your own records without storing the SpacePost id.

import { SpacePost } from "@spacepost/node";

const spacepost = new SpacePost(process.env.SPACEPOST_API_KEY);

await spacepost.emails.send({
  from: "Acme <hello@acme.com>",
  to: "user@example.com",
  subject: "Welcome",
  html: "<p>Hi</p>",
  tags: [
    { name: "category", value: "welcome" },
    { name: "user_id", value: "u_1042" },
  ],
});

curl -X POST https://api.spacepost.dev/emails \
  -H "Authorization: Bearer $SPACEPOST_API_KEY" -H "Content-Type: application/json" \
  -d '{
    "from": "Acme <hello@acme.com>",
    "to": ["user@example.com"],
    "subject": "Welcome",
    "html": "<p>Hi</p>",
    "tags": [{ "name": "category", "value": "welcome" }, { "name": "user_id", "value": "u_1042" }]
  }'

X-SpacePost-Tags: category=welcome, user_id=u_1042

Rules

Up to 50 tags per email.
name and value are each 1 to 256 characters and may contain only ASCII letters, numbers, underscores and dashes (A-Z a-z 0-9 _ -).
Spaces, dots, @ and non-ASCII characters are rejected with a 422. Hash or slug values such as email addresses first, for example user_1042 or a SHA-256 hex digest.