SIGNL4 MCP by usefulapi
REMOTE · SIGNL4.USEFULAPI.IO
Read SIGNL4 alerts, teams, users and duty schedules; raise, acknowledge, close and annotate alerts.
Available components
Last scanned (10 hours ago)
Scores higher than 47% of remote servers
Reachable. Last reached 17 Oct 2026.
Category Monitoring and Observability
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 redirected somewhere other than https, so enforcement is unproven. 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 & Reachability0
- Transport check failed: declared streamable-http, but the endpoint redirected instead of responding directly. See how to fix → View diagnostics → Fail
Schema Quality & AI Usability83
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 2348 tokens (~130/item across 18 items; 18 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management17
- Stability observed for 5 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
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 18 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 19 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
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.
- 17 Oct 26 +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.
- 14 Oct 26 +3
- The server rewrote its instructions, which are the text every model session reads security
- 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 functional
- 13 Oct 26 0
- Stability: unverified → 0.03 ▲ functional
- 12 Oct 26 61
First indexed and scored.
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 17 Oct 2026 · Probed https://signl4.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 | d9be3287b0fde9630e825ba1f79bff3f |
| SANs: usefulapi.io, *.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 signl4.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 | 302 |
WWW-Authenticate challenge Bearer realm="OAuth", resource_metadata="https://signl4.usefulapi.io/.well-known/oauth-protected-resource/mcp"
Bearer realm="OAuth", resource_metadata="https://signl4.usefulapi.io/.well-known/oauth-protected-resource/mcp"Protected resource metadata
| Document | https://signl4.usefulapi.io/.well-known/oauth-protected-resource/mcp |
|---|---|
| Retrieved | Yes |
| Resource | https://signl4.usefulapi.io/mcp |
| Authorisation server | https://signl4.usefulapi.io |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://signl4.usefulapi.io/mcp | Redirected | 302 | https://usefulapi.io/signl4/ |
| http (plaintext) | http://signl4.usefulapi.io/mcp | Inconclusive | 302 | http://signl4.usefulapi.io/mcp |
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 →
signl4_acknowledge_alert Acknowledge alert ~132
WRITE: acknowledge an alert on behalf of a SIGNL4 user (recorded in its history under that user). Stops escalation to further tiers for that alert. POST /v3/signls/{signlId}/acknowledge.
| Name | Type | Req | Description |
|---|---|---|---|
| alert_id | string | yes | Alert (signl) id; get it from signl4_list_alerts or the id returned by signl4_raise_alert. |
| comment | string | – | Optional comment stored with the acknowledgement. |
| user_id | string | yes | The SIGNL4 user the acknowledgement is recorded for; see signl4_list_users. |
No output schema declared.
No examples provided.
signl4_annotate_alert Annotate alert ~134
WRITE: add a text note to an alert's timeline on behalf of a SIGNL4 user. The note is visible to the team in the app. It does not page anyone by itself. POST /v3/signls/{signlId}/annotate.
| Name | Type | Req | Description |
|---|---|---|---|
| alert_id | string | yes | Alert (signl) id; get it from signl4_list_alerts or the id returned by signl4_raise_alert. |
| text | string | yes | The note. |
| user_id | string | yes | The SIGNL4 user the note is recorded for; see signl4_list_users. |
No output schema declared.
No examples provided.
signl4_close_alert Close alert ~124
WRITE: close (resolve) an alert on behalf of a SIGNL4 user; it leaves the open list and stops all further notifications. POST /v3/signls/{signlId}/close.
| Name | Type | Req | Description |
|---|---|---|---|
| alert_id | string | yes | Alert (signl) id; get it from signl4_list_alerts or the id returned by signl4_raise_alert. |
| comment | string | – | Optional comment stored with the closure. |
| user_id | string | yes | The SIGNL4 user the closure is recorded for; see signl4_list_users. |
No output schema declared.
No examples provided.
signl4_get_alert Get alert ~98
Full detail of one alert: title, text, severity, category, status and delivery status, history (who acknowledged/closed it and when), parameters, attachments and escalations with per-user delivery. GET /v3/signls/{signlId}/details.
| Name | Type | Req | Description |
|---|---|---|---|
| alert_id | string | yes | Alert (signl) id; get it from signl4_list_alerts or the id returned by signl4_raise_alert. |
No output schema declared.
No examples provided.
signl4_get_alert_report Get alert report ~97
Alert volume and response statistics per team over several time periods: acknowledged, closed and unhandled counts, overall and per category (optionally for one user). Teams that cannot be read are reported under `errors`. GET /v3/signls/report.
| Name | Type | Req | Description |
|---|---|---|---|
| team_ids | array | – | Limit to these team ids (default: all teams the key can access). |
| user_id | string | – | Report for this user only. |
No output schema declared.
No examples provided.
signl4_get_alert_timeline Get alert timeline ~82
The ordered timeline of an alert: creation, notifications, acknowledgements, annotations, escalations and remote actions. GET /v3/signls/{signlId}/timeline.
| Name | Type | Req | Description |
|---|---|---|---|
| alert_id | string | yes | Alert (signl) id; get it from signl4_list_alerts or the id returned by signl4_raise_alert. |
No output schema declared.
No examples provided.
signl4_get_duty_status Get user duty status ~98
Whether a user is currently on or off duty in each of their teams (dutyMode, onDutyTime, tier). GET /v3/users/{userId}/dutyStatus.
| Name | Type | Req | Description |
|---|---|---|---|
| team_ids | array | – | Limit to these team ids (default: all teams the key can access). |
| user_id | string | yes | SIGNL4 user id (a GUID); get it from signl4_list_users. |
No output schema declared.
No examples provided.
signl4_get_duty_summary Get duty summary ~83
Duty assistant info per team: whether it is enabled and the last two (or all) duty periods. GET /v3/duties/summary.
| Name | Type | Req | Description |
|---|---|---|---|
| last_two_only | boolean | – | Only the last two duties (default true). |
| team_ids | array | – | Limit to these team ids (default: all teams the key can access). |
No output schema declared.
No examples provided.
signl4_get_team Get team ~63
One SIGNL4 team: name, description, time zone, member ids. GET /v3/teams/{teamId}.
| Name | Type | Req | Description |
|---|---|---|---|
| team_id | string | yes | SIGNL4 team id (a GUID); get it from signl4_list_teams. |
No output schema declared.
No examples provided.
signl4_get_user Get user ~67
One SIGNL4 user: name, e-mail, contact addresses, time zone and duty status per team. GET /v3/users/{userId}.
| Name | Type | Req | Description |
|---|---|---|---|
| user_id | string | yes | SIGNL4 user id (a GUID); get it from signl4_list_users. |
No output schema declared.
No examples provided.
signl4_list_alerts List alerts ~276
Search SIGNL4 alerts (signls), newest first, with status, severity, category and history (created, acknowledged, closed). Filter by team, status, creation time, text or external id. Up to 100 per page; pass the returned continuation_token to get the next page. POST /v3/signls/paged (a read).
| Name | Type | Req | Description |
|---|---|---|---|
| category_ids | array | – | Only alerts of these category ids (see signl4_list_categories). |
| continuation_token | string | – | The continuation_token of the previous page. |
| created_after | string | – | ISO 8601 date-time with a timezone, e.g. 2026-10-01T00:00:00Z. |
| created_before | string | – | ISO 8601 date-time with a timezone, e.g. 2026-10-01T00:00:00Z. |
| external_id | string | – | Only alerts raised with this external id. |
| max_results | integer | – | Alerts per page, 1-100 (default 25). |
| status | string | – | Only alerts in this state (default: all). |
| team_ids | array | – | Limit to these team ids (default: all teams the key can access). |
| text | string | – | Free-text search in title and text. |
No output schema declared.
No examples provided.
signl4_list_audit_logs List audit logs ~200
Audit log of changes and events in the SIGNL4 subscription (who changed what, when). Filter by team, time window and message text; pass the returned continuation_token for the next page. GET /v3/audits.
| Name | Type | Req | Description |
|---|---|---|---|
| continuation_token | string | – | The continuation_token of the previous page. |
| from | string | – | ISO 8601 date-time with a timezone, e.g. 2026-10-01T00:00:00Z. |
| max_results | integer | – | Entries per page, 1-200 (default 50). |
| message_contains | string | – | Only entries whose message contains this text. |
| team_ids | array | – | Limit to these team ids (default: all teams the key can access). |
| to | string | – | ISO 8601 date-time with a timezone, e.g. 2026-10-01T00:00:00Z. |
No output schema declared.
No examples provided.
signl4_list_categories List alert categories ~79
List the alert categories of a team (name, color, keywords used to auto-classify alerts). The category name can be passed to signl4_raise_alert. GET /v3/categories/{teamId}.
| Name | Type | Req | Description |
|---|---|---|---|
| team_id | string | yes | SIGNL4 team id (a GUID); get it from signl4_list_teams. |
No output schema declared.
No examples provided.
signl4_list_duty_schedules List duty schedules ~150
Planned on-call duty schedules (who is on duty when): start/end, team, user, tier, stand-in and shift info. Filter by team, user and time window. POST /v3/schedules (a read).
| Name | Type | Req | Description |
|---|---|---|---|
| from | string | – | Start of the window, ISO 8601 with timezone. |
| limit | integer | – | Maximum schedules to return, 1-500 (default 100). |
| team_ids | array | – | Limit to these team ids (default: all teams the key can access). |
| to | string | – | End of the window, ISO 8601 with timezone. |
| user_id | string | – | Only this user's duties. |
No output schema declared.
No examples provided.
signl4_list_team_users List users of teams ~71
List the users of the given teams (all accessible teams by default) with duty status. Teams that cannot be read are reported under `errors`. GET /v3/teams/users.
| Name | Type | Req | Description |
|---|---|---|---|
| team_ids | array | – | Limit to these team ids (default: all teams the key can access). |
No output schema declared.
No examples provided.
signl4_list_teams List teams ~80
List the SIGNL4 teams the API key can access: id, name, description, time zone and member ids. Team ids are needed to raise alerts and to look up categories and duties. GET /v3/teams.
| Name | Type | Req | Description |
|---|---|---|---|
| team_ids | array | – | Limit to these team ids (default: all teams the key can access). |
No output schema declared.
No examples provided.
signl4_list_users List users ~65
List the SIGNL4 users the key can access with name, e-mail, contact addresses, activation state and duty status per team (dutyMode, onDutyTime). User ids are needed to acknowledge/close/annotate alerts. GET /v3/users.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
signl4_raise_alert Raise alert ~232
WRITE: raise a new alert in a SIGNL4 team. THIS NOTIFIES REAL PEOPLE: every team member currently on duty is paged (push, SMS and/or voice call according to their settings) and the alert escalates if nobody acknowledges it. Only use it when the user clearly asked to alert the team; never for tests unless they said so. Not idempotent: a second call pages the team again. Returns the new alert incl. its id. POST /v3/signls.
| Name | Type | Req | Description |
|---|---|---|---|
| category | string | – | Category name, see signl4_list_categories (default: automatic). |
| external_id | string | – | Your own reference for this alert, for later look-up (and for SIGNL4 to group follow-ups). |
| severity | string | – | Severity (default: SIGNL4's default for the team). |
| team_id | string | yes | SIGNL4 team id (a GUID); get it from signl4_list_teams. |
| text | string | yes | Alert message body. |
| title | string | yes | Alert title, shown on the pager screen. |
No output schema declared.
No examples provided.
How do I install the SIGNL4 MCP by usefulapi server?
SIGNL4 MCP by usefulapi is a hosted endpoint at https://signl4.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 · signl4.usefulapi.io
claude mcp add --transport http io-usefulapi-signl4 'https://signl4.usefulapi.io/mcp'
What is the SIGNL4 MCP by usefulapi server?
SIGNL4 MCP by usefulapi is listed in the public MCP registry as io.usefulapi/signl4. Read SIGNL4 alerts, teams, users and duty schedules; raise, acknowledge, close and annotate alerts. This page covers its hosted endpoint (https://signl4.usefulapi.io/mcp).
Is the SIGNL4 MCP by usefulapi server safe to use?
SIGNL4 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 SIGNL4 MCP by usefulapi server expose?
SIGNL4 MCP by usefulapi exposes 18 tools: signl4_list_teams, signl4_get_team, signl4_list_users, signl4_get_user, signl4_list_team_users, and 13 more. Their descriptions and schemas cost roughly 2,131 tokens of context every time the server is loaded.
Does the SIGNL4 MCP by usefulapi server require authentication?
Yes. SIGNL4 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 SIGNL4 MCP by usefulapi server still maintained?
SIGNL4 MCP by usefulapi is still listed as active in the MCP registry. We last reached this channel on 17 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.