io.usefulapi/mailerlite
REMOTE · MAILERLITE.USEFULAPI.IO · SCANNED SEP 20
Read subscribers, groups, campaigns, fields, segments, automations, webhooks; safe additive writes.
Available components
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. How we score → Why this is hard to score →
Endpoint Security78
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- 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. View diagnostics → Pass
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 401, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
- The authorisation server offers only Dynamic Client Registration (RFC 7591), which MCP 2026-07-28 deprecated in favour of Client ID Metadata Documents. View diagnostics → Partial
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability80
- AI-judged instruction clarity (excellent).Pass
- Tool/resource definitions use about 1021 tokens (~78/item across 13 items; 13 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 13 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 13 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities60
- Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28. See how to fix → Fail
How do I install the io.usefulapi/mailerlite MCP server?
io.usefulapi/mailerlite is a hosted endpoint at https://mailerlite.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.
remote · mailerlite.usefulapi.io
claude mcp add --transport http io-usefulapi-mailerlite 'https://mailerlite.usefulapi.io/mcp'
{
"mcpServers": {
"io-usefulapi-mailerlite": {
"url": "https://mailerlite.usefulapi.io/mcp"
}
}
} {
"servers": {
"io-usefulapi-mailerlite": {
"type": "http",
"url": "https://mailerlite.usefulapi.io/mcp"
}
}
} [mcp_servers.io-usefulapi-mailerlite] url = "https://mailerlite.usefulapi.io/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"io-usefulapi-mailerlite": {
"type": "remote",
"url": "https://mailerlite.usefulapi.io/mcp",
"enabled": true
}
}
} openclaw mcp add io-usefulapi-mailerlite --url 'https://mailerlite.usefulapi.io/mcp' --transport streamable-http
mcp_servers:
io-usefulapi-mailerlite:
url: "https://mailerlite.usefulapi.io/mcp" {
"McpServers": {
"io-usefulapi-mailerlite": {
"Transport": "http",
"Url": "https://mailerlite.usefulapi.io/mcp"
}
}
} assistant mcp add io-usefulapi-mailerlite -t streamable-http -u 'https://mailerlite.usefulapi.io/mcp'
{
"mcpServers": {
"io-usefulapi-mailerlite": {
"type": "http",
"url": "https://mailerlite.usefulapi.io/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 1 Sept 26 +68
- Transport: unverified → pass ▲ security
- Authorization: unverified → pass ▲ security
- Injection markers: unverified → pass ▲ security
- Stability: unverified → pass ▲ security
- MCP protocol: unverified → fail ▼ functional
- Endpoint reachability: not serving MCP → reachable ▲ functional
- Tool coverage: unverified → 100 ▲ functional
- 30 Aug 26 −68
- Endpoint reachability: reachable → not serving MCP ▼ security
- Authorization: pass → unverified ▼ security
- Stability: pass → unverified ▼ security
- Tool safety: pass → unverified ▼ security
- Transport: pass → unverified ▼ security
- Capabilities: fail → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- 26 Aug 26 +1
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.
- 23 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 87 to 90. That category is still filling its 30-day observation window: 26 days of observed history at the previous scan, 27 at this one. The score rises as the window fills, whether or not the server changes.
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 31 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 30 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 20 Sept 2026 · Probed https://mailerlite.usefulapi.io/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=usefulapi.io | CN=WE1,O=Google Trust Services,C=US | 13 Sept 2026 | 12 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | 9279d9ab47c2f4a61319757751e81241 |
| SANs: usefulapi.io, mailerlite.usefulapi.io, *.mailerlite.usefulapi.io | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of mailerlite.usefulapi.io. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| io. | present | 57355 | 8 | Verified |
| usefulapi.io. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication Enforced and verified
The endpoint asked for a token and published valid RFC 9728 metadata describing how to get one.
| Result | Enforced and verified |
|---|---|
| Enforced | On tool calls |
| HTTP status | 200 |
WWW-Authenticate challenge Bearer realm="OAuth", resource_metadata="https://mailerlite.usefulapi.io/.well-known/oauth-protected-resource/mcp", error="invalid_token", error_description="Missing or invalid access token"
Bearer realm="OAuth", resource_metadata="https://mailerlite.usefulapi.io/.well-known/oauth-protected-resource/mcp", error="invalid_token", error_description="Missing or invalid access token"Protected resource metadata
| Document | https://mailerlite.usefulapi.io/.well-known/oauth-protected-resource/mcp |
|---|---|
| Retrieved | Yes |
| Resource | https://mailerlite.usefulapi.io/mcp |
| Authorisation server | https://mailerlite.usefulapi.io |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://mailerlite.usefulapi.io/mcp | Verified | 200 | |
| http (plaintext) | http://mailerlite.usefulapi.io/mcp | Inconclusive | 401 |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
mailerlite_assign_subscriber_to_group Assign subscriber to group ~63
Adds a subscriber to a group (additive membership). MailerLite API: POST /subscribers/{subscriber_id}/groups/{group_id}.
| Name | Type | Req | Description |
|---|---|---|---|
| group_id | string | yes | Group id. |
| subscriber_id | string | yes | Subscriber id. |
No output schema declared.
No examples provided.
mailerlite_create_group Create group ~41
Creates a subscriber group/list (additive). MailerLite API: POST /groups.
| Name | Type | Req | Description |
|---|---|---|---|
| name | string | yes | Name of the new group. |
No output schema declared.
No examples provided.
mailerlite_get_campaign Get campaign ~44
Fetch a single campaign by id. Read-only. MailerLite API: GET /campaigns/{campaign_id}.
| Name | Type | Req | Description |
|---|---|---|---|
| campaign_id | string | yes | Campaign id. |
No output schema declared.
No examples provided.
mailerlite_get_subscriber Get subscriber ~46
Fetch a single subscriber by id or email address. MailerLite API: GET /subscribers/{id}.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Subscriber id OR email address. |
No output schema declared.
No examples provided.
mailerlite_list_automations List automations ~87
List automations (workflows), optionally filtered by enabled state. Page-paginated. MailerLite API: GET /automations.
| Name | Type | Req | Description |
|---|---|---|---|
| filter_enabled | boolean | – | Filter by enabled state (→ filter[enabled]). |
| limit | integer | – | Max automations per page (default 25). |
| page | integer | – | Page number (page-based pagination). |
No output schema declared.
No examples provided.
mailerlite_list_campaigns List campaigns ~94
List campaigns, optionally filtered by status. Page-paginated. Read-only — this server does NOT send campaigns. MailerLite API: GET /campaigns.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | Max campaigns per page (default 25). |
| page | integer | – | Page number (page-based pagination). |
| status | string | – | Filter by status (→ filter[status]): sent | draft | ready. |
No output schema declared.
No examples provided.
mailerlite_list_fields List fields ~102
List custom/default subscriber fields, optionally filtered by type or keyword. Page-paginated. MailerLite API: GET /fields.
| Name | Type | Req | Description |
|---|---|---|---|
| keyword | string | – | Filter by keyword (→ filter[keyword]). |
| limit | integer | – | Max fields per page (default 25). |
| page | integer | – | Page number (page-based pagination). |
| type | string | – | Filter by field type (→ filter[type]): text | number | date. |
No output schema declared.
No examples provided.
mailerlite_list_group_subscribers List group subscribers ~107
List the subscribers belonging to a group, optionally filtered by status. Cursor-paginated. MailerLite API: GET /groups/{group_id}/subscribers.
| Name | Type | Req | Description |
|---|---|---|---|
| cursor | string | – | Pagination cursor from a previous response's meta.next_cursor. |
| group_id | string | yes | Group id. |
| limit | integer | – | Max subscribers per page (default 25, max 100). |
| status | string | – | Filter by status (→ filter[status]). |
No output schema declared.
No examples provided.
mailerlite_list_groups List groups ~100
List subscriber groups/lists, optionally filtered by name. Page-paginated. MailerLite API: GET /groups.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | Max groups per page (default 25). |
| name | string | – | Filter by name (→ filter[name]). |
| page | integer | – | Page number (page-based pagination). |
| sort | string | – | Sort field, e.g. name, total, -total, created_at. |
No output schema declared.
No examples provided.
mailerlite_list_segments List segments ~56
List segments. Page-paginated. MailerLite API: GET /segments.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | Max segments per page (default 25). |
| page | integer | – | Page number (page-based pagination). |
No output schema declared.
No examples provided.
mailerlite_list_subscribers List subscribers ~100
List subscribers, optionally filtered by status. Cursor-paginated. MailerLite API: GET /subscribers.
| Name | Type | Req | Description |
|---|---|---|---|
| cursor | string | – | Pagination cursor from a previous response's meta.next_cursor. |
| limit | integer | – | Max subscribers to return per page (default 25, max 100). |
| status | string | – | Filter by status (→ filter[status]): active | unsubscribed | unconfirmed | bounced | junk. |
No output schema declared.
No examples provided.
mailerlite_list_webhooks List webhooks ~61
List configured webhooks. Page-paginated. MailerLite API: GET /webhooks.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | Max webhooks per page (default 25). |
| page | integer | – | Page number (page-based pagination). |
No output schema declared.
No examples provided.
mailerlite_upsert_subscriber Upsert subscriber ~120
Creates or updates a subscriber (upsert by email). Additive — does NOT send any email. MailerLite API: POST /subscribers.
| Name | Type | Req | Description |
|---|---|---|---|
| string | yes | Subscriber email address (upsert key). | |
| fields | object | – | Custom/default field values keyed by field key, e.g. { name, last_name, company }. |
| groups | array | – | Group id strings to add the subscriber to. |
| status | string | – | Subscriber status: active | unsubscribed | unconfirmed | bounced | junk. |
No output schema declared.
No examples provided.
What is the io.usefulapi/mailerlite MCP server?
io.usefulapi/mailerlite is an MCP server listed in the public MCP registry as io.usefulapi/mailerlite. Read subscribers, groups, campaigns, fields, segments, automations, webhooks; safe additive writes. This page covers its hosted endpoint (https://mailerlite.usefulapi.io/mcp).
Is the io.usefulapi/mailerlite MCP server safe to use?
io.usefulapi/mailerlite scores 86 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 io.usefulapi/mailerlite MCP server expose?
io.usefulapi/mailerlite exposes 13 tools: mailerlite_list_subscribers, mailerlite_get_subscriber, mailerlite_list_groups, mailerlite_list_group_subscribers, mailerlite_list_campaigns, and 8 more. Their descriptions and schemas cost roughly 1,021 tokens of context every time the server is loaded.
Does the io.usefulapi/mailerlite MCP server require authentication?
Yes. io.usefulapi/mailerlite 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 io.usefulapi/mailerlite MCP server still maintained?
io.usefulapi/mailerlite is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.