io.usefulapi/customerio

REMOTE · CUSTOMERIO.USEFULAPI.IO · SCANNED AUG 3

Query people, segments, campaigns, and message deliveries; send transactional email or broadcasts.

Available components

+4 this week 72 72 Trust /100

Trust breakdown (6 categories)

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 →

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 not yet verified: we couldn't determine whether a plaintext access path exists. 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 Usability71

AI-judged instruction clarity (good).Pass
Tool/resource definitions use about 1016 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 Management23

Stability observed for 7 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial

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

Capabilities60

Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28. See how to fix → Fail

Install

Add this component to your MCP client. Where a client-specific snippet is available, pick your client below and copy it straight into your config; otherwise use the connection detail shown.

remote · customerio.usefulapi.io

Claude Codex opencode OpenClaw Hermes Other

# add to Claude Code

claude mcp add --transport http io-usefulapi-customerio https://customerio.usefulapi.io/mcp

# ~/.codex/config.toml

[mcp_servers.io-usefulapi-customerio]
url = "https://customerio.usefulapi.io/mcp"

// opencode.json

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

# add to OpenClaw

openclaw mcp add io-usefulapi-customerio --url https://customerio.usefulapi.io/mcp --transport streamable-http

# ~/.hermes/config.yaml

mcp_servers:
  io-usefulapi-customerio:
    url: "https://customerio.usefulapi.io/mcp"

// mcp.json

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

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

Changelog

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.

3 Aug 26 +1

No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.
2 Aug 26 +53
- Authorization: unverified → pass ▲ security
- Transport: fail → pass ▲ security
- MCP protocol: unverified → fail ▼ functional
- Endpoint reachability: not serving MCP → reachable ▲ functional
- Stability: unverified → 0.20 ▲ functional
- Tool coverage: unverified → 100 ▲ functional
1 Aug 26 −52
- Endpoint reachability: reachable → not serving MCP ▼ security
- Stability: 0.13 → unverified ▼ security
- Authorization: pass → unverified ▼ security
- Transport: pass → fail ▼ security
- Tool coverage: 100 → unverified ▼ functional
- Capabilities: fail → unverified ▼ functional
31 Jul 26 +3
- 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 −2
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
29 Jul 26 +1

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.
28 Jul 26 0
- Stability: unverified → 0.03 ▲ functional
27 Jul 26 +56
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional

Show 5 earlier entries Hide earlier entries

Diagnostics

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 3 Aug 2026 · Probed https://customerio.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	17 Jul 2026	15 Oct 2026	ECDSA 256	ECDSA-SHA256	1adac3c085e720fc13c6a920b8ca7092
SANs: usefulapi.io, customerio.usefulapi.io, *.customerio.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

DNSSEC insecure

Validation of customerio.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://customerio.usefulapi.io/.well-known/oauth-protected-resource/mcp", error="invalid_token", error_description="Missing or invalid access token"

Bearer realm="OAuth", resource_metadata="https://customerio.usefulapi.io/.well-known/oauth-protected-resource/mcp", error="invalid_token", error_description="Missing or invalid access token"

Protected resource metadata

Document	https://customerio.usefulapi.io/.well-known/oauth-protected-resource/mcp
Retrieved	Yes
Resource	https://customerio.usefulapi.io/mcp
Authorisation server	https://customerio.usefulapi.io

Transports 2 probes

Transport	URL	Outcome	Status	Location
streamable-http	https://customerio.usefulapi.io/mcp	Verified	200
http (plaintext)	http://customerio.usefulapi.io/mcp	Inconclusive	401

MCP tools — 13 exposed · ~1,016 tokens

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.

Tool Tokens

customerio_get_campaign Get campaign ~39

Get a single campaign by id. App API: GET /v1/campaigns/{campaign_id}.

Input Output Examples

Name	Type	Req	Description
campaign_id	—	yes	Campaign id.

No output schema declared.

No examples provided.

customerio_get_campaign_metrics Get campaign metrics ~90

Get delivery/engagement metrics for a campaign over time. App API: GET /v1/campaigns/{campaign_id}/metrics.

Input Output Examples

Name	Type	Req	Description
campaign_id	—	yes	Campaign id.
period	string	—	Bucket size. Default days.
steps	integer	—	Number of periods to return.
type	string	—	Metric type filter (e.g. email, push, sms).

No output schema declared.

No examples provided.

customerio_get_customer_attributes Get customer attributes ~57

Get a single person's attributes (profile fields). App API: GET /v1/customers/{customer_id}/attributes.

Input Output Examples

Name	Type	Req	Description
customer_id	string	yes	The person's id (or cio_id / email, per your identifier setup).

No output schema declared.

No examples provided.

customerio_get_customer_messages Get customer messages ~76

List messages (deliveries) sent to a single person. App API: GET /v1/customers/{customer_id}/messages.

Input Output Examples

Name	Type	Req	Description
customer_id	string	yes	The person's id.
limit	integer	—	Max messages to return.
start	string	—	Pagination cursor from a previous response's `next`.

No output schema declared.

No examples provided.

customerio_get_customer_segments Get customer segments ~46

List the segments a single person belongs to. App API: GET /v1/customers/{customer_id}/segments.

Input Output Examples

Name	Type	Req	Description
customer_id	string	yes	The person's id.

No output schema declared.

No examples provided.

customerio_list_campaigns List campaigns ~29

List all campaigns in the workspace. App API: GET /v1/campaigns.

Input Output Examples

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

customerio_list_collections List collections ~29

List reusable data collections in the workspace. App API: GET /v1/collections.

Input Output Examples

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

customerio_list_exports List exports ~27

List data exports in the workspace. App API: GET /v1/exports.

Input Output Examples

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

customerio_list_messages List messages ~126

List sent messages (deliveries) across the workspace, filterable by type/campaign/newsletter. App API: GET /v1/messages.

Input Output Examples

Name	Type	Req	Description
campaign_id	—	—	Filter to a specific campaign.
drafts	boolean	—	Include drafts.
limit	integer	—	Max messages to return.
newsletter_id	—	—	Filter to a specific newsletter.
start	string	—	Pagination cursor from a previous response's `next`.
type	string	—	Message type filter, e.g. email \| push \| sms \| in_app \| webhook \| slack \| twilio.

No output schema declared.

No examples provided.

customerio_list_segments List segments ~33

List all segments in the workspace (id + name + type). App API: GET /v1/segments.

Input Output Examples

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

customerio_search_customers Search customers ~117

Search/list people by a Customer.io filter (segment or attribute conditions). e.g. filter={"segment":{"id":7}} or {"and":[...]}. App API: POST /v1/customers.

Input Output Examples

Name	Type	Req	Description
filter	object	yes	Customer.io filter object, e.g. {"segment":{"id":7}} or {"and":[{"attribute":{"field":"email","operator":"exists"}}]}.
limit	integer	—	Max people to return.
start	string	—	Pagination cursor from a previous response's `next`.

No output schema declared.

No examples provided.

customerio_send_transactional_email Send transactional email ~191

⚠️ SENDS A REAL EMAIL. Send a transactional email using a transactional message template. Delivers immediately to the `to` recipient. App API: POST /v1/send/email.

Input Output Examples

Name	Type	Req	Description
body	string	—	Override the email body.
disable_message_retention	boolean	—	If true, don't retain the message body.
from	string	—	Override the sender address.
identifiers	object	yes	Person identifiers, e.g. {"id":"..."} or {"email":"..."}.
message_data	object	—	Template variables (liquid) to interpolate into the message.
send_to_unsubscribed	boolean	—	If true, send even to unsubscribed recipients.
subject	string	—	Override the subject line.
to	string	yes	Recipient email address.
transactional_message_id	—	yes	The transactional message template id (or trigger name).

No output schema declared.

No examples provided.

customerio_trigger_broadcast Trigger broadcast ~156

⚠️ SENDS TO REAL RECIPIENTS. Trigger an API-triggered broadcast, delivering to the resolved recipient set. App API: POST /v1/send/broadcast (posts to /v1/campaigns/{broadcast_id}/triggers).

Input Output Examples

Name	Type	Req	Description
broadcast_id	—	yes	The API-triggered broadcast id.
data	object	—	Liquid variables available to the broadcast templates.
email_add_duplicates	boolean	—	Allow duplicate email recipients.
email_ignore_missing	boolean	—	Skip recipients missing an email instead of erroring.
id_ignore_missing	boolean	—	Skip recipients missing an id instead of erroring.
recipients	object	—	Recipient filter object (overrides the broadcast's configured audience).

No output schema declared.

No examples provided.

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Scoring key

80+ high trust
60–79 medium
below 60 low

How we score

Score history · last 30 days

26 Jul 3 Aug

Day	Score
26 Jul	12
27 Jul	68
28 Jul	68
29 Jul	69
30 Jul	67
31 Jul	70
1 Aug	18
2 Aug	71
3 Aug	72