Buttondown API Skill

This skill enables you to interact with the Buttondown newsletter platform via its REST API. The API follows standard RESTful conventions, so operations are straightforward CRUD calls.

Authentication

All requests require the user's API key, available from https://buttondown.com/requests.

Use the BUTTONDOWN_API_KEY environment variable
Send it as: Authorization: Token $BUTTONDOWN_API_KEY

Before making any API call, verify the env var is set. If it's missing, tell the user to set it:

export BUTTONDOWN_API_KEY="your-api-key-here"

Base URL

https://api.buttondown.com/v1

All endpoint paths below are relative to this base.

Making Requests

Use curl for all API calls. Standard patterns:

# GET (list/retrieve)
curl -s -H "Authorization: Token $BUTTONDOWN_API_KEY" \
  "https://api.buttondown.com/v1/{resource}"

# POST (create)
curl -s -X POST \
  -H "Authorization: Token $BUTTONDOWN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"field": "value"}' \
  "https://api.buttondown.com/v1/{resource}"

# PATCH (update)
curl -s -X PATCH \
  -H "Authorization: Token $BUTTONDOWN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"field": "new_value"}' \
  "https://api.buttondown.com/v1/{resource}/{id}"

# DELETE
curl -s -X DELETE \
  -H "Authorization: Token $BUTTONDOWN_API_KEY" \
  "https://api.buttondown.com/v1/{resource}/{id}"

Pipe responses through jq for readable output. Use jq -r when extracting specific values.

Pagination

List endpoints return paginated results. The response includes:

count: total number of results
next: URL for next page (null if last page)
previous: URL for previous page (null if first page)
results: array of objects

To fetch all results, follow next URLs until null.

Automations

Automations perform actions automatically based on triggers. Each automation has three parts:

Trigger -- the event that starts it (e.g., a new subscriber confirms)
Filter (optional) -- criteria that narrow when it runs
Actions -- what happens (send email, add tag, send webhook, post to social media, etc.)

Automations can be active or paused. Changes to automation emails affect all future subscribers, including those waiting on a delayed action. Changes to the action list only affect subscribers who trigger the automation after the change.

List automations

GET /automations

Create an automation

POST /automations

Body includes trigger configuration and actions. Key fields:

name: descriptive name for the automation
trigger: the event that starts it (e.g., subscriber.tags.changed, subscriber.confirmed, subscriber.created, email.sent)
status: "active" or "inactive"
filters: object with filters array, groups array, and predicate ("and" or "or")
actions: array of action objects with timing

Filter fields

tags -- matches subscribers who have a specific tag
special.tags_changed -- matches when a specific tag was just added (use this for tag-based automations to avoid re-triggering)

send_email action structure

Automation emails are defined inline in the action, not as separate email objects:

{
  "type": "send_email",
  "metadata": {
    "subject": "Email subject",
    "body": "<!-- buttondown-editor-mode: fancy -->Email body in markdown",
    "email_id": "",
    "template": ""
  },
  "timing": {
    "time": "immediate",
    "delay": {"value": "0", "unit": "days", "time_of_day": null}
  }
}

For delayed emails, set time to "delay" and adjust the delay object (e.g., {"value": "3", "unit": "days"}).

Retrieve an automation

GET /automations/{id}

Update an automation

PATCH /automations/{id}

Delete an automation

DELETE /automations/{id}

Available action types

Send email -- send a specific email to the subscriber
Add tag -- tag the subscriber
Send webhook -- POST to an external URL
Post to social media -- share to Bluesky, LinkedIn, or Twitter (requires connected integrations)
Send Discord invitation -- invite subscriber to a Discord server

Each action can be immediate or delayed (e.g., "send welcome email immediately, then add VIP tag after 7 days").

Subscribers

For reference, though not the primary focus of this skill, the subscriber endpoints are available:

List subscribers

GET /subscribers

Create a subscriber

POST /subscribers

Required: email_address. Optional: type ("regular" to skip double opt-in), tags (array), metadata (object), ip_address.

Update a subscriber

PATCH /subscribers/{id_or_email}

Accepts either subscriber ID or email address as the identifier. Note: changing type from premium to unsubscribed will cancel the subscriber's Stripe subscription.

Delete a subscriber

DELETE /subscribers/{id}

Emails

For reference, email/newsletter endpoints:

List emails

GET /emails

Create an email

POST /emails

The API auto-detects content type (plain text, HTML, or Markdown). You can explicitly set the format with a comment at the start of the body:

Note: the API rejects bodies starting with YAML frontmatter (---). To bypass, include the header X-Buttondown-Live-Dangerously: true.

Retrieve an email

GET /emails/{id}

Tips

Always show the user what you're about to do before making destructive calls (DELETE, bulk updates). Confirm with them first.
When listing resources, format the output as a clean table or summary rather than dumping raw JSON.
If a create/update call fails, check the response body for error details and relay them clearly.
The API returns UUIDs as IDs. When the user refers to a tag or automation by name, list first to find the matching ID.

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