# SIGNL4 MCP by usefulapi (remote · signl4.usefulapi.io)

Read SIGNL4 alerts, teams, users and duty schedules; raise, acknowledge, close and annotate alerts.

- Trust score: 65/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-17

## Components

- remote · `signl4.usefulapi.io`: 65/100 (this document), [markdown](https://verifymcp.io/servers/io-usefulapi-signl4/signl4.md), [page](https://verifymcp.io/servers/io-usefulapi-signl4/signl4)

## Channel facts

- Endpoint: `https://signl4.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 2026-10-17.

- **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 (excellent).
  - 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.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 17/100
  - Stability observed for 5 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% 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 18 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 19 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 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.

### Claude

```bash
claude mcp add --transport http io-usefulapi-signl4 'https://signl4.usefulapi.io/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "io-usefulapi-signl4": {
      "url": "https://signl4.usefulapi.io/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "io-usefulapi-signl4": {
      "type": "http",
      "url": "https://signl4.usefulapi.io/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.io-usefulapi-signl4]
url = "https://signl4.usefulapi.io/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "io-usefulapi-signl4": {
      "type": "remote",
      "url": "https://signl4.usefulapi.io/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add io-usefulapi-signl4 --url 'https://signl4.usefulapi.io/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  io-usefulapi-signl4:
    url: "https://signl4.usefulapi.io/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "io-usefulapi-signl4": {
      "Transport": "http",
      "Url": "https://signl4.usefulapi.io/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add io-usefulapi-signl4 -t streamable-http -u 'https://signl4.usefulapi.io/mcp'
```

### Other

```json
{
  "mcpServers": {
    "io-usefulapi-signl4": {
      "type": "http",
      "url": "https://signl4.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.

### 2026-10-14 (score 64, +3)

- [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 (18)

### `signl4_list_teams` (~80 tokens)

List teams

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.

Input parameters:

- `team_ids` (array): Limit to these team ids (default: all teams the key can access).

### `signl4_get_team` (~63 tokens)

Get team

One SIGNL4 team: name, description, time zone, member ids. GET /v3/teams/{teamId}.

Input parameters:

- `team_id` (string, required): SIGNL4 team id (a GUID); get it from signl4_list_teams.

### `signl4_list_users` (~65 tokens)

List users

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.

### `signl4_get_user` (~67 tokens)

Get user

One SIGNL4 user: name, e-mail, contact addresses, time zone and duty status per team. GET /v3/users/{userId}.

Input parameters:

- `user_id` (string, required): SIGNL4 user id (a GUID); get it from signl4_list_users.

### `signl4_list_team_users` (~71 tokens)

List users of teams

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.

Input parameters:

- `team_ids` (array): Limit to these team ids (default: all teams the key can access).

### `signl4_list_categories` (~79 tokens)

List alert categories

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}.

Input parameters:

- `team_id` (string, required): SIGNL4 team id (a GUID); get it from signl4_list_teams.

### `signl4_list_alerts` (~276 tokens)

List alerts

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).

Input parameters:

- `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.

### `signl4_get_alert` (~98 tokens)

Get alert

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.

Input parameters:

- `alert_id` (string, required): Alert (signl) id; get it from signl4_list_alerts or the id returned by signl4_raise_alert.

### `signl4_get_alert_timeline` (~82 tokens)

Get alert timeline

The ordered timeline of an alert: creation, notifications, acknowledgements, annotations, escalations and remote actions. GET /v3/signls/{signlId}/timeline.

Input parameters:

- `alert_id` (string, required): Alert (signl) id; get it from signl4_list_alerts or the id returned by signl4_raise_alert.

### `signl4_get_alert_report` (~97 tokens)

Get alert report

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.

Input parameters:

- `team_ids` (array): Limit to these team ids (default: all teams the key can access).
- `user_id` (string): Report for this user only.

### `signl4_raise_alert` (~232 tokens)

Raise alert

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.

Input parameters:

- `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, required): SIGNL4 team id (a GUID); get it from signl4_list_teams.
- `text` (string, required): Alert message body.
- `title` (string, required): Alert title, shown on the pager screen.

### `signl4_acknowledge_alert` (~132 tokens)

Acknowledge alert

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.

Input parameters:

- `alert_id` (string, required): 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, required): The SIGNL4 user the acknowledgement is recorded for; see signl4_list_users.

### `signl4_close_alert` (~124 tokens)

Close alert

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.

Input parameters:

- `alert_id` (string, required): 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, required): The SIGNL4 user the closure is recorded for; see signl4_list_users.

### `signl4_annotate_alert` (~134 tokens)

Annotate alert

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.

Input parameters:

- `alert_id` (string, required): Alert (signl) id; get it from signl4_list_alerts or the id returned by signl4_raise_alert.
- `text` (string, required): The note.
- `user_id` (string, required): The SIGNL4 user the note is recorded for; see signl4_list_users.

### `signl4_list_duty_schedules` (~150 tokens)

List duty schedules

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).

Input parameters:

- `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.

### `signl4_get_duty_status` (~98 tokens)

Get user duty status

Whether a user is currently on or off duty in each of their teams (dutyMode, onDutyTime, tier). GET /v3/users/{userId}/dutyStatus.

Input parameters:

- `team_ids` (array): Limit to these team ids (default: all teams the key can access).
- `user_id` (string, required): SIGNL4 user id (a GUID); get it from signl4_list_users.

### `signl4_get_duty_summary` (~83 tokens)

Get duty summary

Duty assistant info per team: whether it is enabled and the last two (or all) duty periods. GET /v3/duties/summary.

Input parameters:

- `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).

### `signl4_list_audit_logs` (~200 tokens)

List audit logs

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.

Input parameters:

- `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.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/io-usefulapi-signl4/signl4#diagnostics

## Score history

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

## Common questions

### 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.

## Links

- Remote endpoint: https://signl4.usefulapi.io/mcp
- Repository: https://github.com/m190/usefulapi-mcp
- Website: https://usefulapi.io/signl4/
- Changelog RSS feed: https://verifymcp.io/servers/io-usefulapi-signl4/signl4.xml
- Changelog JSON feed: https://verifymcp.io/servers/io-usefulapi-signl4/signl4.json
- HTML version of this page: https://verifymcp.io/servers/io-usefulapi-signl4/signl4