# Buttondown MCP by usefulapi (remote · buttondown.usefulapi.io)

Read Buttondown subscribers, emails, analytics and automations; add subscribers; write email drafts.

- Trust score: 65/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-18

## Components

- remote · `buttondown.usefulapi.io`: 65/100 (this document), [markdown](https://verifymcp.io/servers/io-usefulapi-buttondown/buttondown.md), [page](https://verifymcp.io/servers/io-usefulapi-buttondown/buttondown)

## Channel facts

- Endpoint: `https://buttondown.usefulapi.io/mcp`
- Transports: `streamable-http`
- Auth: `required`
- Version: `1.0.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-18.

- **Endpoint Security**: 78/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation is enforced on tool calls, advertised via RFC 9728 protected-resource metadata. Discovery is public, which costs nothing: no tool can be invoked without a token.
  - HTTPS enforcement could not be verified: the plaintext port redirected somewhere other than https, so enforcement is unproven.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
  - The authorisation server offers only Dynamic Client Registration (RFC 7591), which MCP 2026-07-28 deprecated in favour of Client ID Metadata Documents.
- **Transport & Reachability**: 0/100
  - Transport check failed: declared streamable-http, but the endpoint redirected instead of responding directly.
- **Schema Quality & AI Usability**: 83/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 2862 tokens (~114/item across 25 items; 25 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 20/100
  - Stability observed for 6 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 96/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 89% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 25 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 26 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 60/100
  - Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28.

## Install

### How do I install the Buttondown MCP by usefulapi server?

Buttondown MCP by usefulapi is a hosted endpoint at https://buttondown.usefulapi.io/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http io-usefulapi-buttondown 'https://buttondown.usefulapi.io/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "io-usefulapi-buttondown": {
      "url": "https://buttondown.usefulapi.io/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "io-usefulapi-buttondown": {
      "type": "http",
      "url": "https://buttondown.usefulapi.io/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.io-usefulapi-buttondown]
url = "https://buttondown.usefulapi.io/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "io-usefulapi-buttondown": {
      "type": "remote",
      "url": "https://buttondown.usefulapi.io/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add io-usefulapi-buttondown --url 'https://buttondown.usefulapi.io/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  io-usefulapi-buttondown:
    url: "https://buttondown.usefulapi.io/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "io-usefulapi-buttondown": {
      "Transport": "http",
      "Url": "https://buttondown.usefulapi.io/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add io-usefulapi-buttondown -t streamable-http -u 'https://buttondown.usefulapi.io/mcp'
```

### Other

```json
{
  "mcpServers": {
    "io-usefulapi-buttondown": {
      "type": "http",
      "url": "https://buttondown.usefulapi.io/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-10-17 (score 65, +1)

No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-15 (score 64, +1)

No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-14 (score 63, +2)

- [security] The server rewrote its instructions, which are the text every model session reads
- [functional] The server now declares the “prompts” capability
- [functional] First check of Schema quality: 100
- [functional] New prompt “getting_started”
- [functional] Server version: 1.0.0 → 1.1.0

### 2026-10-13 (score 61, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-12 (score 61)

First indexed and scored.

## MCP tools (25)

### `buttondown_get_account` (~31 tokens)

Get account

The Buttondown account this API key belongs to: username and e-mail address. GET /accounts/me.

### `buttondown_list_newsletters` (~76 tokens)

List newsletters

List the newsletters on the account with name, username, domains, sender, locale and timezone. The newsletter's API key, custom CSS and e-mail templates are never returned. GET /newsletters.

Input parameters:

- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.

### `buttondown_get_newsletter` (~68 tokens)

Get newsletter

One newsletter by id (settings and identity only; no API key, CSS or templates). GET /newsletters/{id}.

Input parameters:

- `newsletter_id` (string, required): The object's Buttondown id (a UUID or a prefixed id such as em_..., sub_..., tag_...).

### `buttondown_list_subscribers` (~240 tokens)

List subscribers

List or search subscribers (newest first by default) with e-mail, type (regular, unactivated, unsubscribed, premium, ...), tags, notes, metadata, source, open/click rates and dates. Filter by e-mail text, type, tag, signup date or domain. GET /subscribers.

Input parameters:

- `created_after` (string): Only subscribers created on or after this date (yyyy-mm-dd).
- `created_before` (string): Only subscribers created before this date (yyyy-mm-dd).
- `domain` (array): Only subscribers whose e-mail domain is one of these.
- `email_address` (string): Only subscribers whose e-mail address contains this text.
- `not_type` (array): Exclude subscribers of these types.
- `ordering` (string): Sort field, - for descending (default -creation_date).
- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.
- `tag` (array): Only subscribers with these tag names.
- `type` (array): Only subscribers of these types (e.g. regular, unactivated, unsubscribed).

### `buttondown_get_subscriber` (~62 tokens)

Get subscriber

One subscriber by id or by e-mail address: type, tags, notes, metadata, source, engagement and lifecycle dates. GET /subscribers/{id_or_email}.

Input parameters:

- `id_or_email` (string, required): The subscriber's id or e-mail address.

### `buttondown_add_subscriber` (~268 tokens)

Add a subscriber

WRITE: add ONE subscriber by e-mail address. No subscriber type is set, so Buttondown applies the newsletter's normal sign-up rules (double opt-in: the subscriber is typically created as unactivated and Buttondown e-mails THAT ONE address a confirmation message; opt-in is never bypassed, nor is the firewall). Only add people who asked to subscribe. Creating a subscriber (and its tags) can also start the newsletter's own automations, which may e-mail that one subscriber. An existing e-mail is left untouched (error, no overwrite). Optional tags (a tag that does not exist is created, which needs a plan with tags), a private note and metadata. Buttondown limits creation to 100 subscribers per day. POST /subscribers.

Input parameters:

- `email_address` (string, required): The new subscriber's e-mail address. They receive the confirmation e-mail.
- `metadata` (object): Free-form key-value data stored on the subscriber.
- `notes` (string): Private note (never shown to the subscriber).
- `referrer_url` (string): Where the subscriber came from.
- `tags` (array): Tag names to apply.
- `utm_campaign` (string)
- `utm_medium` (string)
- `utm_source` (string)

### `buttondown_update_subscriber` (~203 tokens)

Update a subscriber's tags, notes or metadata

WRITE: change ONE subscriber's tags, private note or metadata. Tags are merged (add_tags / remove_tags change only those names; the others stay). A given note or metadata replaces the existing value (destructive for that field). The subscriber's type (unsubscribe, block, ...) and e-mail address cannot be changed here, and this tool sends nothing itself; but a tag, note or metadata change can start the newsletter's own automations (for example a tag-triggered welcome sequence), which may e-mail that one subscriber. PATCH /subscribers/{id_or_email}.

Input parameters:

- `add_tags` (array): Tag names to add.
- `id_or_email` (string, required): The subscriber's id or e-mail address.
- `metadata` (object): Replace the subscriber's metadata object with this one.
- `notes` (string): Replace the private note with this text (empty string clears it).
- `remove_tags` (array): Tag names to remove.

### `buttondown_list_emails` (~234 tokens)

List emails

List emails (drafts, scheduled and sent), newest first by default, with subject, status, publish date, slug, archive URL and analytics summary. The body is left out unless include_body is set. Filter by status, subject text or date. GET /emails.

Input parameters:

- `created_after` (string): Only emails created on or after this date (yyyy-mm-dd).
- `created_before` (string): Only emails created before this date (yyyy-mm-dd).
- `include_body` (boolean): Include each email's full body (large). Default false.
- `ordering` (string): Sort order (default -creation_date).
- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.
- `published_after` (string): Only emails published on or after this date (yyyy-mm-dd).
- `published_before` (string): Only emails published before this date (yyyy-mm-dd).
- `status` (array): Only emails with these statuses (draft, scheduled, sent, ...).
- `subject` (string): Only emails whose subject contains this text.

### `buttondown_get_email` (~72 tokens)

Get email

One email by id with its full body, subject, status, publish date, slug, archive settings and analytics summary. GET /emails/{id}.

Input parameters:

- `email_id` (string, required): The object's Buttondown id (a UUID or a prefixed id such as em_..., sub_..., tag_...).

### `buttondown_get_email_analytics` (~81 tokens)

Get email analytics

Delivery and engagement numbers for one sent email: recipients, deliveries, opens, clicks, failures, unsubscriptions, complaints, replies, page views. GET /emails/{id}/analytics.

Input parameters:

- `email_id` (string, required): The object's Buttondown id (a UUID or a prefixed id such as em_..., sub_..., tag_...).

### `buttondown_create_email_draft` (~150 tokens)

Create an email draft

WRITE: create a DRAFT email (status always "draft"). Nothing is sent or scheduled and no subscriber is e-mailed; to send it, the user must open the draft in Buttondown and send it there. This server has no tool that sends or schedules email. Body is Markdown or HTML. POST /emails.

Input parameters:

- `body` (string): Email body in Markdown (or HTML).
- `canonical_url` (string): URL of the original source of the content.
- `description` (string): Short description used for archives and SEO.
- `image` (string): Preview image URL.
- `slug` (string): Archive URL slug.
- `subject` (string, required): Subject line.

### `buttondown_update_email_draft` (~173 tokens)

Edit an email draft

WRITE: edit the subject, body, description, slug or preview image of an email that is still a DRAFT (replaces those fields; the previous text is lost unless Buttondown's email history is used). Refuses any email that is not a draft, and never changes status or publish date, so nothing is sent or scheduled. PATCH /emails/{id}.

Input parameters:

- `body` (string): New body in Markdown (or HTML); replaces the whole body.
- `canonical_url` (string)
- `description` (string)
- `email_id` (string, required): The object's Buttondown id (a UUID or a prefixed id such as em_..., sub_..., tag_...).
- `image` (string)
- `slug` (string)
- `subject` (string)

### `buttondown_list_tags` (~55 tokens)

List tags

List subscriber tags with name, color, descriptions and whether subscribers can edit them. GET /tags.

Input parameters:

- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.

### `buttondown_get_tag_analytics` (~48 tokens)

Get tag analytics

Subscribers created, open rate and click rate for one tag. GET /tags/{id}/analytics.

Input parameters:

- `tag_id` (string, required): Tag id (see buttondown_list_tags).

### `buttondown_create_tag` (~124 tokens)

Create a tag

WRITE: create a subscriber tag (needs a Buttondown plan with tags). An existing tag with the same name is returned as an error and not changed. POST /tags.

Input parameters:

- `color` (string, required): Hex color, e.g. #FFD700.
- `description` (string): Internal description (only you see it).
- `name` (string, required): Tag name (up to 100 characters).
- `public_description` (string): Public description shown in the subscriber portal.
- `subscriber_editable` (boolean): Let subscribers add/remove this tag themselves. Default false.

### `buttondown_list_automations` (~87 tokens)

List automations

List automations (welcome sequences and other triggered e-mails) with name, status, trigger, actions and filters (webhook URLs in actions are shown by host only). Read-only: automations are not started or changed. GET /automations.

Input parameters:

- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.

### `buttondown_get_automation` (~62 tokens)

Get automation

One automation by id with its trigger, actions and filters. GET /automations/{id}.

Input parameters:

- `automation_id` (string, required): The object's Buttondown id (a UUID or a prefixed id such as em_..., sub_..., tag_...).

### `buttondown_get_automation_analytics` (~60 tokens)

Get automation analytics

Performance numbers for one automation. GET /automations/{id}/analytics.

Input parameters:

- `automation_id` (string, required): The object's Buttondown id (a UUID or a prefixed id such as em_..., sub_..., tag_...).

### `buttondown_list_surveys` (~65 tokens)

List surveys

List surveys with question, answers, status and response count. GET /surveys.

Input parameters:

- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.
- `status` (string): Only surveys with this status.

### `buttondown_list_survey_responses` (~135 tokens)

List survey responses

List survey responses (who answered what), optionally for one survey, email or subscriber. GET /survey_responses.

Input parameters:

- `created_after` (string): A date, yyyy-mm-dd.
- `created_before` (string): A date, yyyy-mm-dd.
- `email_id` (string): Only responses submitted from this email.
- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.
- `subscriber_id` (string): Only responses by this subscriber (id, not e-mail).
- `survey_id` (string): Only responses to this survey.

### `buttondown_list_segments` (~50 tokens)

List segments

List saved subscriber segments with name, description and filters. GET /segments.

Input parameters:

- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.

### `buttondown_list_forms` (~55 tokens)

List forms

List sign-up forms with title, slug, status, tags and subscriber counts. GET /forms.

Input parameters:

- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.

### `buttondown_list_snippets` (~58 tokens)

List snippets

List reusable content snippets with identifier, name, mode and how often each is referenced. GET /snippets.

Input parameters:

- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.

### `buttondown_list_webhooks` (~67 tokens)

List webhooks

List configured webhooks with status and subscribed event types. The signing key is never returned and the URL is shown by host only. GET /webhooks.

Input parameters:

- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.

### `buttondown_list_events` (~132 tokens)

List email events

List delivery events (delivered, opened, clicked, bounced, unsubscribed, ...), newest first, optionally for one email or subscriber. GET /events.

Input parameters:

- `email_id` (string): Only events for this email.
- `event_type` (string): Only events of this type.
- `page` (integer): Page number, from 1 (default 1). Pass the previous reply's next_page.
- `page_size` (integer): Results per page, 1-500 (default 100).
- `subscriber_id` (string): Only events for this subscriber (id, not e-mail).

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/io-usefulapi-buttondown/buttondown#diagnostics

## Score history

- 2026-10-18: 65
- 2026-10-17: 65
- 2026-10-16: 64
- 2026-10-15: 64
- 2026-10-14: 63
- 2026-10-13: 61
- 2026-10-12: 61

## Common questions

### What is the Buttondown MCP by usefulapi server?

Buttondown MCP by usefulapi is listed in the public MCP registry as io.usefulapi/buttondown. Read Buttondown subscribers, emails, analytics and automations; add subscribers; write email drafts. This page covers its hosted endpoint (https://buttondown.usefulapi.io/mcp).

### Is the Buttondown MCP by usefulapi server safe to use?

Buttondown MCP by usefulapi scores 65 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Buttondown MCP by usefulapi server expose?

Buttondown MCP by usefulapi exposes 25 tools: buttondown_get_account, buttondown_list_newsletters, buttondown_get_newsletter, buttondown_list_subscribers, buttondown_get_subscriber, and 20 more. Their descriptions and schemas cost roughly 2,656 tokens of context every time the server is loaded.

### Does the Buttondown MCP by usefulapi server require authentication?

Yes. Buttondown MCP by usefulapi asked us for credentials when we connected, so you will need to authorise it in your MCP client before it can do anything.

### Is the Buttondown MCP by usefulapi server still maintained?

Buttondown MCP by usefulapi is still listed as active in the MCP registry. We last reached this channel on 18 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://buttondown.usefulapi.io/mcp
- Repository: https://github.com/m190/usefulapi-mcp
- Website: https://usefulapi.io/buttondown/
- Changelog RSS feed: https://verifymcp.io/servers/io-usefulapi-buttondown/buttondown.xml
- Changelog JSON feed: https://verifymcp.io/servers/io-usefulapi-buttondown/buttondown.json
- HTML version of this page: https://verifymcp.io/servers/io-usefulapi-buttondown/buttondown